"Engineering design is a decision making process required to optimally convert resources into systems, components or processes to meet desired needs." -- Dr. D. A. Lucca (possibly quoting someone else).
A #design describes how to apply #tools to materials.
David Cary also maintains related pages:
[a few extremely common materials, and a few exotic materials]
CSPC (cellulose core, silicon matrix, polyester-filled composite -- otherwise known as fiberglass over hot-glued corrugated cardboard). This material is light, waterproof, cheap, and easy to build in any arbitrary shape.-- Steve Roberts http://www.microship.com/bike/behemoth/packaging.html [materials]
Supplies: [FIXME: is this the same as #materials ? ]
Batteries finishing nails wire WD-40 superglue Duct Tape masking tape scotch tape (writable with pencil) clear contact paper paint spare light bulbs ziplock bags trash bags
Screwdriver Tape measure hammer scissors pliers (needle-nose) flashlight Dentist's Mirror toolbox extension cord power strip
furniture: [FIXME: house considerations ? office space ?]
chair desk bookshelves lamp trash bucket plastic mat to go under chair
Pet Peeve: I despise the versions that have friction -- the ones where if you turn off your engine, you start slowing down and eventually stop. This makes it unnecessarily hard to understand Einstein's theory of relativity. The completely frictionless ones are better -- since in the real world velocity *is* truly relative.
Pet peeve: Please *do not* peel the stickers off and rearrange them to "fix" the cube. They never stick back on very well, and soon fall off and are lost. Instead, if you *must* have it fixed and you don't have the patience to do that merely by twisting, *guess what's inside first*, then *take it apart* into "individual cubes". It's quite surprising how the whole thing holds together (mechanical engineering). Sure, it's "looser" after you do this, but easier-to-spin is not a bad thing. [FIXME: describe exactly how to get the 1st cube out, or link to a page that does.] http://search.dmoz.org/cgi-bin/search?search=rubik [FIXME: do I need 2 copies, 1 here, one at dav_info.html ?]
[rubik cube / typography ?] http://www.lineto.com/application.html?ID=122&dir_id=121
Rubik's Cube by Karl Dahlke http://www.eklhad.net/rubik/ has a on-line program that allows you to enter your current rubic's cube configuration, and it tells you step-by-step how to solve it. (You can download the source code to the program).
``As far as I know I am the fastest active cuber in Britain with a best average of 23.0 seconds'' -- stiff_hands http://homepage.ntlworld.com/angela.hayden/cube/cube_frontpage.html
traditional architecture (designing buildings on the ground to support the humans inside).
related to learning.html , #design , #synergetics , #city [should I move ``city design'' info there ?], #spacecraft_design , #furniture , computer_architecture.html ,
Design, in general.
What I call "general design" seems to be the same as what others call "the meta-field of design" (Adam Greenfield) and "design science" (Buckminster Fuller).
See also simplicity
see also spacecraft_design
see also FUD (Fear Uncertainty and Doubt) learning.html#fud
see also general-purpose tools vs. single-purpose tools #general_purpose
``Water floats a ship. Water sinks a ship'' -- Chinese proverb
"If we make peaceful revolution impossible, we make violent revolution inevitable." - John F. Kennedy
"Poison is in everything, and no thing is without poison. The dosage makes it either a poison or a remedy." -- Theophrastus Bombastus von Hohenheim
[FIXME: ___ ... applied to computer architecture. ]
[FIXME: this also applies to functional data compression -- move those snippets there.] [FIXME: move to unknowns.html] [FIXME: #furniture]
Architects know that some kinds of design problems are more personal than others. One of the cleanest, most abstract design problems is designing bridges. There your job is largely a matter of spanning a given distance with the least material. The other end of the spectrum is designing chairs. Chair designers have to spend their time thinking about human butts.
Most of us hate to acknowledge this. Designing systems of great mathematical elegance sounds a lot more appealing to most of us than pandering to human weaknesses. ...
I think almost anything you can do to make programs shorter is good. There should be lots of library functions; anything that can be implicit should be; the syntax should be terse to a fault; even the names of things should be short.
And it's not only programs that should be short. The manual should be thin as well. A good part of manuals is taken up with clarifications and reservations and warnings and special cases. If you force yourself to shorten the manual, in the best case you do it by fixing the things in the language that required so much explanation.
What New Abstractions Are Left to Discover?
I'm not sure how reasonable a hope this is, but one thing I would really love to do, personally, is discover a new abstraction-- something that would make as much of a difference as having first class functions or recursion or even keyword parameters. This may be an impossible dream. These things don't get discovered that often. But I am always looking.
-- Ross M. Greenberg, in article "Windows NT in the Enterprise" in Network Computing 1999-03-22
"To me, there are only a few things worse than a poor implementation of a good idea. One is watching that good idea get caught up in never-ending add-a-feature-hell, and another is for it to be committee-ized to death. Even worse is a scenario where the idea doesn't ever get implemented and users never find out why. "
-- Rodney Rhodes
Recently, upon finding myself in a rental car ... This feature worked differently than in my own car, however, because holding down the button an extra second didn't engage the auto-down function. I instinctively double-clicked the button the next time and was delighted when the window lowered itself automatically. Now if I could just get an Undo command for my oven ...
-- Ed. "Letters" Macworld (www.macworld.com) Jan 1996
An Undo command for the oven -- the mind reels ! How about an eyedropper tool for selecting the exact shade of toast you want ? ...
[FIXME: move to unknowns.html ? or just link back here ?]
Mathematicians call good work "beautiful," and so, either now or in the past, have scientists, engineers, musicians, architects, designers, writers, and painters. Is it just a coincidence that they used the same word, or could there be some overlap in what they meant? If there is an overlap, can we use one field's discoveries about beauty to help us in another?
... ``how do you make good stuff?''
... The same principles of good design crop up again and again.
Good design is simple. ...
Good design is timeless. ...
Good design solves the right problem. ... Problems can be improved as well as solutions. ...
Good design is suggestive. ... ... a building or object should let you use it how you want: a good building, for example, will serve as a backdrop for whatever life people want to lead in it, instead of making them live as if they were executing a program written by the architect.
Good design is often slightly funny. ...
Good design is hard. ... Not every kind of hard is good. ... You want the kind of pain you get from going running, not the kind you get from stepping on a nail. ...
Good design looks easy. ...
Good design uses symmetry. ... There are two kinds of symmetry, repetition and recursion. Recursion means repetition in subelements, like the pattern of veins in a leaf. ... The Eiffel Tower looks striking partly because it is a recursive solution, a tower on a tower.
Good design resembles nature. ... It's not cheating to copy. ...
Good design is redesign. ... Mistakes are natural. Instead of treating them as disasters, make them easy to acknowledge and easy to fix. ... Open-source software has fewer bugs because it admits the possibility of bugs. ... It helps to have a medium that makes change easy. ...
Good design can copy. ...
Good design is often strange. ...
Good design happens in chunks. ... Nothing is more powerful than a community of talented people working on related problems. ... but great work still comes disproportionately from a few hotspots: the Bauhaus, the Manhattan Project, the New Yorker, Lockheed's Skunk Works, Xerox Parc. ... At any given time there are a few hot topics and a few groups doing great work on them, and it's nearly impossible to do good work yourself if you're too far removed from one of these centers. ...
Good design is often daring. ...
Re:Go NASA. Faster, better Cheaper. (Score:1)
by Gurlia (email@example.com) on Tuesday November 30, @04:08PM EST (#52)
This is probably off-topic... but, WoW! I'm surprised by the parallels to Open Source software... Just consider: these little tough probes are made by shooting them with air-guns into desert ground. Sounds like Open Source software being released to the public early, let people find where and why it broke, then developers use that to make it better, more crash-proof, and so on, ad infinitum, until we finally arrive at something like Linux, stable, robust, and just solid in general.
This sure does sound like the Cathedral and the Bazaar (credits to ESR) to me... NASA had been spending all that money building these intricate "cathedrals" (aka the traditional spacecrafts). And, try as hard as they might, there have always been all kinds of problems with delicate equipment breaking, etc., and tons of $$$ are spent on fixing or preventing these problems. Compare this with the two "crash-land-with-style" probes: built by a totally different philosophy (ie., crash 'em as hard as you can then make it tougher so it won't break next time, instead of spending years at the drawing board coming up with a "beautiful" and complex cathedral design), very resistant to harsh treatment, etc.. This new approach is cheaper, smaller, better. Reminds anyone of MS bloatware vs. the small but super-stable Linux? The parallel to Open Source software is simply amazing...
(Disclaimer: I have been reading Slashdot too much, and this Open Source thing is just getting into my head... argh, time to get back to programming! :-D )
-- 1999 ? http://slashdot.org/comments.pl?sid=2719
As Professor Bryson puts it, "You can only make one thing best at a time." ...
... It is tempting to fix many design variables and select a few at a time to optimize, then fix these and vary others. This is known as partial optimization or sub-optimization ...
"Optimal" Redesign of Cessna Cardinal.
DAV: Of course we would prefer the global optimum. But I want to avoid the ``everything must change'' extremism computer_architecture.html#everything_must_change . Clever designs can partition parts that have little to do with each other. Then each part can be independently optimized. See #don_reinertsen . This is one reason to ``ask for what you really want'' creed.html#really_want , because adding more constraints or asking for something a little different gives a (sometimes very) different result.
Design your system for debugging, starting from the beginning. When you are creating a design, imagine the worst possible places for a bug and create a way to debug them. Lay the ground work ahead of time for debugging with your client or your product design team. Know what procedures you will use and what data you will have to collect.
As far as I know, none of these people has ever killed again. Locking up someone who has made this tragic mistake in the past will have no effect on future deaths, and it is future deaths on which we must focus.
Only one group has the ability to stop future deaths: The safety experts who continue to insist we put our children in the backseat while ignoring that, for many people, "out of sight, out if mind" is literally true.
DAV: another example of counter-intuitive results, and the importance of measuring whether it really helps ( video_game.html#Michael_Abrash ). see also learning.html#mike_males for another example of doing something to ``save the children'' that just makes things worse.
-- Adam Greenfield http://www.alistapart.com/stories/bathingape/
I think there's a common misperception... that design is an endeavor that concerns the decoration of a surface in an attempt to achieve aesthetic distinction or beauty.
... success in design strongly implies a satisfying the requirements of a user. This is what distinguishes it from art or self-expression...
... Within the meta-field of design -- something that to me encompasses graphic design, typography, industrial design, interior design, architecture, fashion, even gardening, maybe even cuisine -- you'd have to be pretty thick to miss the broad movement towards utility, simplicity, and clarity.
In some cases, this may have been driven by a plain love for the clean line, the spare façade, the frisson of absolutist glee one can derive from submitting to an ideology likeless is more.But my understanding is that the will towards simplicity was driven -- over a very long time, and in a great many places -- by a real and increasing concern for the human being using the designed object in question.
... good (i.e., deep) design is ... potentially a lubricant and a cushion to smooth, simplify and mitigate all the inevitable daily hassles we're presented with by having the temerity to live in an era of complexity.
general-purpose tools vs. single-purpose tools.
see also generalize vs. specialize dav_info.html#generalize_specialize
DAV: I am having a little cognitive dissonance here.
On one hand, I think it's really cool to have general-purpose tools. General-purpose PCs that can do lots of things never envisioned by their original designer, ... PDAs that can accept new and improved software ... multipurpose tools that do lots of stuff and still fit in your pocket (rather than having to carry around an entire tackle box of single-purpose tools) ...
On the other hand, single-purpose tools are also nice. ... telephones that ``just work'', unlike some PDA/cellphone combos that seem to crash regularly ... ... A knife that's just a knife ... ... The single purpose tools in Unix ``cut'', ``sort'', etc. ... email handling programs that just handle email, rather than displaying animated graphics and relaying virus programs to everyone else in your address book ... tools that are optimized to do one thing well, and when you have a collection of them and one does not work, all the rest of them are unaffected. (In other words, when you let someone else borrow one tool, or one tool wears out or breaks, or the batteries in one tool are drained, or you lose a tool). ... multipurpose tools often have one thing they do well, but all other secondary abilities are a compromise.
The importance of scalability/upgradeability: idea_space.html#level It's much easier to improve my collection of tools (not only in dollar cost, but in time spent learning how to use the new, improved collection) if I can simply add a simple new tool and learn how to use it, then (after I am comfortable with the new tool) discarding old tools it makes redundant. As opposed to getting a complicated new tool, spending much longer getting used to its new quirks, then trying to remember all the different functions of complicated old tools, worring that if I discard this old tool, even though most of its functions are obsoleted by the old tool, perhaps I might still need this old tool to do the 1 or 2 things that the new tool doesn't do as well -- or worse, doesn't do at all.
Occasionally one thing can be both ``simple'' and ``multifunctional'' -- graphic display hardware without complex arbitrary restrictions on what text/colors can go where ... ... paper for origami folding ... bookshelves that are smart enough *not* to make every shelf the same height, so that they can hold all different sizes of books or display objects d'art without wasting lots of space, ... dremel tools come close ... what else ?
-- ``less is more (more or less)'' chapter by William Buxton
`` superappliances: the behavioral implications of artifacts
... the Swiss Army Knife http://www.swissarmy.com/ joins the Cuisinart as a single device that can perform a wide range of functions. ...
... both ... represent what I call a superappliance. ... both the personal computer and the interactive television [also] fall into this category. ...
... appliances of this class all share the following properties:
- Multiple function. ... functionality otherwise delivered through a number of simpler special-purpose devices.
- Single location. ... The higher the overhead or inconvenience in moving the appliance, the more constrained functionality becomes.
- Single user. ...
- Single function at a time. ...
- Space/complexity trade-off. These multifunction appliances are inherently more complex than any of the single-function tools that they overlap with. This is largely due to the overhead in switching the modality from one function to the other. On the other hand, they typically occupy less space and cost less than the equivalent set of single-function tools.
... it would be shortsighted to assume that there are not viable design alternatives to the digital superappliance.
One foundation of the discipline of the architecture of buildings is the design of physical space appropriate for particular activities. This way of thinking is perhaps best captured in the following quote from the architect Louis I. Kahn:
Thoughts exchanged by one and another are not the same in one room as in another.
... we associate specific locations with specific activities. ...
... with conventional specialized tools, each activity can take place independent from, and simultaneously with, any other activity...
... Rather than converging toward ever more complex multifunction tools, my claim is that going forward we must diverge toward a set of simpler, more-specialized tools. ...
plumbing, the Internet, and the Waternet
... there is little significant difference among personal computers that hang on the Internet. On the more mature Waternet, this is not the case. Attached to it are diverse appliances such as sinks, lawn sprinklers, toilets, baths, showers, fire hydrants, and so on.
... the reason the Palm Pilot succeeded when its predecessors had failed is that the designers specified the product in human terms rather than technological terms. ... the need to fit into a jacket pocket, to be able to find an address faster than one could in a traditional address book, and to find ``Whan can I have dinner with you ?'' or ``Am I free next Thursday ?'' faster than one could with a traditional date book. They also included the specification that one should be able to back up the contents of the device in one button push, so that if the device was lost, one would only lose the cost of the device, not the information.
on strength versus generality
... Why not achieve both strength and generality by having a suite of strong-specific tools ? ... even though each tool may be individually manageable, their collective complexity rapidly exceeds a human's ability to cope. ... the cognitive load imposed on the user in order to take advantage of the tools.
... when the strong-specific tools are digital and networked, they have ... the capacity to communicate and cooperate, thereby assuming much of the load that would otherwise burden the user. ...
... when a call comes in, the phone can notify the stereo to turn down the music. ...
... automotive electronics ... make up about 30 percent of the cost of a modern car... These systems involve real-time, process control, information sharing, and networked cooperating parallel processors from diverse vendors. If I am right, this type of system is what will soon appear in our office and home systems. Yet, given that most schools still focus on teaching traditional functional programming, how well are we preparing our students for this inevitable change in computing paradigm ?
devices as notation
... with Roman numerals... long division (from a question of cognitive load) was about as hard as second-year calculus is today...
... computers are notational instruments par excellence that have the potential to reduce the complexity of today's world, much as the introduction of the decimal did for mathematics in the past.
... to determine longitude ... With the introduction of the chronometer, the calculations were reduced to simple arithmetic and could be done in minutes. In the sense of causing a reduction in complexity, the chronometer was arguably as important a notational device as the decimal.
Increasing complexity is the enemy, and well-designed devices, appropriately deployed, can play a significant role in turning this tide.
design in front of the glass: what you see (hear and touch) is what you think you get
... two of the most powerful observations that a designer of computers could have. ...
- You can change the input/output devices.
- By your choice, you can have a huge influence shaping the end user's mental model of the system.
example 2: e-commerce beyond the Amazon
... Symbol Technologies http://www.symbol.com/ ... the amount of e-commerce that goes through browsers driven by their technology likely exceeds the total e-commerce being transacted on all Netscape and Internet Explorer browsers combined (including Amazon.com) by about 5 million times! How can this be ... ? ... Symbol Technologies is the largest manufacturer of barcode readers in the world ... most people would claim that checking out groceries is not e-commerce... the transactions run over the same wires, routers, and servers as most other e-commerce. ...
the Renaissance is over -- long live the Renaissance
... our earlier discussion of weak-general versus strong-specific systems.
The exact same issues that we saw in this discussion are evident in the tension between the need for discipline specialization versus general holistic knowledge. Given the much-discussed constraints on human ability, how can we expect an individual to maintain the requisite specialist knowledge in their technical discipline, while at the same time have the needed competence in industrial design, sociology, anthropology, psychology, and so on, which this essay implies are needed to do one's job ?
so does the solution in this case lie in a social network of specialized individuals. ... however, in this case, it is due to a social network of people rather than a network of computers.
In 1959, Sir Charles P. Snow ... the science community and that of the arts and humanities... Snow characterized these two communities as having ... lost the ability to communicate on any plane of serious intellectual endeavor. ... He coined the term the two cultures to characterize the polarization of these two communities.
... A commonly expressed view ... can be reduced to ``Let us create a community of Renaissance men and women, instead of these specialists.'' I would suggest that the result of this would be a culture of mediocre generalists, which is not what we need. ...
On the other hand, the notion of a Renaissance team is entirely viable: a social network of specialists ... But while viable, the systemic biases of language, funding, and institutional barriers make this type of team the exception rather than the norm.
... our educational system ... in the rare cases where team performance is encouraged, more often than not, it is a homogenous, rather than a heterogeneous, team from the perspective of skills and culture, in the C.P. Snow sense.
-- _The Invisible Future: the seamless integration of technology with everyday life_ book edited by Peter J. Denning, editor. 2002 [idea_space; #architecture; ?]
I think simplicity is such a important general design rule that it deserves a section all by itself.
related local pages:
Marissa Mayer, who keeps Google's home page pure, understands that less is more. Other tech companies are starting to get it, too. Here's why making things simple is the new competitive advantage.http://www.fastcompany.com/magazine/100/beauty-of-simplicity.html
In October of 1969, the computer industry journal, Datamation, noted that DEC's PDP-11 was much more powerful than the AGC, but this is beside the point. Simpler systems are inherently easier to program, maintain, and fail less often.[simplicity; space hardware]
-- marx on Mon May 26th, 2003 http://www.kuro5hin.org/comments/2003/5/23/134430/275?pid=277
... even geniuses can easily get confused when there is too much complexity. If we can keep everything very simple, except possibly some part about error estimates or something similar, then the field will be less confusing, it will be open to more people, and progress will be faster.
... There seems to be a kind of culture in some parts of science that the one who presents the most difficult and convoluted equations has won, i.e. if you have succeeded in presenting something which no one else can fully understand, then you cannot be criticized. It should be the opposite; the one who can explain something in the simplest way should "win".
This is nothing new, it's simply Occam's Razor, but for some reason it seems to have fallen out of grace lately.
-- Jan Gray http://www.fpgacpu.org/log/sep00.html#000919 [FIXME: crosslink to computer_architecture.html#FPGA or computer_architecture.html#simple_cpu ]
``A theme of my work: for FPGA CPU cores, simple is beautiful. In my experience, ...
- smaller is cheaper
- smaller is faster
- smaller is more power frugal
- simpler is easier to test
I am a disbeliever of anything that requires ... much documentation, head-scratching, hand-waving, and eyes-glazing-over.-- Dave Winer, quoted at http://www.zeldman.com/ which has further thoughts on the subject.
DECEMBER 1, 1999- "Complexity increases the possibility of failure; a twin-engine airplane has twice as many engine problems as a single-engine airplane." By analogy, in both software and electronics, the rule that simplicity increases robustness. It is correspondingly argued that the right way to build reliable systems is to put all your eggs in one basket, after making sure that you've built a really good basket.
Source: The New Hacker's Dictionary -- http://www.linuxcare.com/news_columns/lingo/archive_99december.epl ... (Is it in the Jargon File ? creed.html#jargon )
"Frugal-Ed" is a forum for educators to discuss frugal or simple living and voluntary simplicity.-- http://csf.colorado.edu/archive/
`` There was a man named do Bono, a Maltese, who wished to investigate the process of creative thinking. He prepared for an experiment a room with two doors, one across from other. You go in one door, cross the room and then you walk out the other. He put at the door entrance some material--two flat boards, some ropes. And he got as his subjects some young children. He said to the children "This is a game we play. You must go through this room and out the other door. You must not touch the floor with any part of your body, or clothing.". All of the children figured out what to do -- they tied the one board to each foot and they walked across the room like on skis.
Now he performed second part of the experiment. He gave only one board instead of two. This time the children adopted the trick with a difference. They tied the rope to the end of single board and then stood on it, and jumped up, tugging the rope to pull the board forward, hopping and tugging, moving a little bit at a time. The average time to cross in the second part was less than in the first time.
Why didn't children in the first group think of the trick? They looked at what they were given to use for materials and, they like all of us, wanted to use everything. But they did not need everything. They could do better with less, in a different way. ''
-- Frederik Pohl, The Gold at the Starbow's End
`` The other nice side effect of the minimalistic approach Palm's designers took with this model is it uses remarkably little power. It has only a 16 MHz processor, which draws very little current. The backlight is a big source of power drain but the Zire doesn't have one of these. Color screens use a lot of power but this model doesn't have one of these, either. Even RAM draws power so by keeping this down to [2 MB]. In short, the Zire may use the least amount of power of any handheld Palm has made since its very first model.
I've been using a Zire as much as physically possible since I got it and the internal battery has so far completely defeated my attempts to drain it. ... The usual estimate is someone uses their handheld for 30 minutes a day so you might get away with charging a Zire only once every couple of months. Compared with handhelds that have to be charged almost every day, this is phenomenal. ''
the Dana's rugged simplicity means it's less likely to have either hardware or software problems-- "A Dana for Every Schoolkid? : Using Palm software, this device offers many laptop-like benefits at a fraction of the cost" article by Stephen H. Wildstrom 2003-04-21 http://www.businessweek.com/magazine/content/03_16/b3829030.htm [FIXME: crosslink with wearable_electronic.html#dana ?]
Stuff related to Buckminster Fuller (who apparently coined the word "synergy"), his World Game, and geometry. (tensegrity ?)
... The irony, however, is that if somehow we could have gotten Galileo and Fuller together over lunch, Galileo would have perhaps found Fuller positively mad.http://www.historyguide.org/intellect/lecture6a.html
A vast overabundance of this Earthian cosmic energy income is now technically impoundable and distributable to humanity by presently proven technology. We are not allowed to enjoy this primarily because tax-hungry government bureaucracies and money-drunk big business can't figure a way of putting meters between these cosmic energy sources and the Earthian passengers, so nothing is done about it. The technical equipment -- steel plows, shovels, wheelbarrows, boilers, copper tubing, etc. -- essential to individuals' successful harvesting of their own cosmic energy income cannot be economically produced in the backyard kitchen, garage, or studio without the large scale industrial tools' production elsewhere of industrial materials and tools-that-make-tools involving vast initial capital investments. If big business and big government don't want to amass and make available adequate capital for up-to-date technological tooling, people will rarely be able to tap the cosmic energy income, except by berry-, nut-, mushroom-, or apple-picking and by fishing.
-- http://osearth.com/workshops/whysimulationswork.shtml [FIXME: books_to_read][FIXME: #simplicity]
Engineer and author John Lienhard might well have been describing o.s.EARTH's mission in his wonderful book The Engines of our Ingenuity:
We now use the term black box any time we have to describe a function that we hide from sight. It has practically turned into a metaphor for our retreat from understanding how things work....Educating a strong and capable citizenry means teaching students that someone else's subject matter is not a black box, that those boxes can and must be opened. Once we realize that we cannot deal with part of a system in isolation, it becomes very clear that encasing knowledge in boxes is one of the most destructive things we do.
So how do we open black boxes when they grow so complex? We need to find the threads of simplicity that run through them.
-- Oxford University Press, pp. 170-171
--R. Buckminster Fuller quoted at http://www.pbs.org/wnet/bucky/ http://www.wnet.org/archive/bucky.cgi (these 2 seem identical) http://www.lsi.usp.br/usp/rod/bucky/buckminster_fuller.html "Interesting People & Ideas" http://www.lclark.edu/~miller/ideas.html#bucky http://www.plexus.org/chalkboard/land/messages/214.html
I'm not trying to counsel any of you to do anything really special except to dare to think and to dare to go with the truth and to dare to really love completely.
-- R. Buckminster Fuller http://www.westnet.com/~crywalt/inventions/inv_138.html
Consequently, I also said in 1927, "Here I am launching a half-century-magnitude program with nobody telling me to do so, or suggesting how to do it." I had absolutely no money and my darling wife (who has now been married to me for 66 years) was willing to go along with my thinking and commitments. I said to myself, "If I, in confining my activity to inventing, proving and improving, and physically producing artifacts suggested to me by physical challenges of the a priori environment, which inventions alter the environment consistently with evolution's trending, whereby I am doing that which is compatible with what universal evolution seems intent upon doing -- which is to say, if I am doing what God wants done, i.e., employing my mind to help other humans' minds to render all humanity a physically self-regenerative and comprehensively intellectual integrity success so that humans can effectively give their priority of attention to the ongoing local Universe information-gathering and local problem-solving, primarily with design-science artifact solutions which will altogether result in comprehensive environmental transformation leading to conditions so favorable to humans' physical wellbeing and metaphysical equanimity as to permit humans to become permanently engaged with only the by-mind-conceived challenges of local Universe -- then I do not have to worry about not being commissioned to do so by any Earthians and I don't have to worry how we are going to acquire the money, tools, and services necessary to produce the successively evoluting special-case physical artifacts that will most effectively increase humanity's technological functioning advantage to an omnisuccess-producing degree."
Other pages with long list of Buckminster Fuller links:
http://web.shorty.com/geeks/96/sep/msg00159.html how to mismake a soccer ball Subject: how to mismake a soccer ball From: (Anton Sherwood) Date: Tue, 3 Sep 1996 23:24:53 -0700 I wrote a little C program to enumerate the ways to make a closed ball from 12 pentagons and up to 20 hexagons. (I don't care whether the faces are regular, because I got on this track by wondering about the varieties of buckyballs.) I thought I'd have to build (and debug) a representation of the polygons and their connections. Easier to do the search by hand... But eventually it hit me that all I need is a bit string representing the convex and concave vertices of the boundary of the incomplete ball. Solutions = 526363 Dead ends = 21982613 Face overflows = 19186580 Edge overflows = 410 The output is also a bit string: 1 for a pentagon, 0 for a hexagon; and they're added in a strict spiral sequence, so even though the program knows nothing about the shape, it's easy for a human to build it up from its code. Each solution appears in the tree 120/G times, where G is the size of its symmetry group. And what's my point in doing this? Well, if you should ever want to build a dome house with a square floor, let me know! Anton Sherwood *\\* +1 415 267 0685 *\\* "NO!!! Not THAT button!!!"
|shape||size in unit tetras (or unit triangles)||size in unit cubes (or unit squares)|
|equilateral triangle with sides of length s (see #t(x) for details)||s^2||s^2 * sqrt(3) / 4|
|equilateral triangle with sides of length 2*s||4*s^2||s^2 * sqrt(3)|
|square with sides of length s||s^2 * 4 / sqrt(3)||s^2|
|square with diagonal of length s||s^2 * 2 / sqrt(3)||s^2 / 2|
|area of hexagon inscribed inside a circle of radius r||r^2 * 6||r^2 * 3 * sqrt(3) / 2|
|area of hexagon circumscribed around a circle of radius r (it's pretty easy to see that once you chop out the inscribed hexagon, the 6 remaining fragments can be assembled into 2 more triangles the same size as the 6 interior trangles)||r^2 * 8||r^2 * 6 / sqrt(3)|
|area of 12-gon (dodecagon) inscribed inside a circle of radius r||r^2 * 12 * sin(π/12)*cos(π/12) * 4/sqrt(3) =~= 6.9 * r^2||3 * r^2. I find this a great mystery.|
|area of 12-gon (dodecagon) circumscribed around a circle of radius r||r^2 * ... =~= 7.4 * r^2||r^2 * 12 * sin(π/12)/cos(π/12) =~= 3.2 * r^2|
|area of a circle of radius r (obviously more than the 6 triangles of the inscribed hexagon ... the little leftovers between that hexagon and the circle add up to a bit more than 1 more triangle) (obviously more than the 2 squares of the inscribed square with diagonal of length 2*r ... the little leftovers add up to a bit more than 1 more square)||4*π*r^2 / sqrt(3) =~= 7.26*r^2||pi*r^2 = π*r^2 =~= 3.14*r^2|
|area of pentagon with sides of length s||s^2 * sqrt( 25 + 10*sqrt(5) ) / sqrt(3)||s^2 * sqrt( 25 + 10*sqrt(5) ) / 4|
|area of sphere (compare the unit dodecahedron, which has a surface of 20 unit triangles ...)||16*pi*r^2 / sqrt(3) =~= (29.02)*r^2||4*pi*r^2 =~= (12.566)*r^2|
|volume of a sphere http://mathworld.wolfram.com/Sphere.html /* was sphere */ = 2/3 the volume of cylinder circumscribed around it||4*pi*r^3/3|
|volume of cylinder circumscribed around unit sphere||2*pi*r^2|
|the Platonic solids http://mathworld.wolfram.com/PlatonicSolid.html|
|volume of regular tetrahedon with edges of length s||s^3||s^3 / ( 6 * sqrt(2) )|
|volume of regular tetrahedon with edges of length sqrt(2)||2*sqrt(2)||1/3|
|volume of cube with edges of length s||s^3 * 6 * sqrt(2)||s^3|
|volume of cube with face diagonal of length s||s^3 * 3||s^3 * / ( 2 * sqrt(2) )|
|volume of regular octahedron with edges of length s||s^3 * 4||s^3 * sqrt(2) / 3|
|volume of regular dodecahedron with edges of length s||s^3 * 3 * sqrt(10) * ( φ )^4 = s^3 * ( 15 + 7 * sqrt(5) ) * sqrt(2) * 3 / 2||s^3 * sqrt(5) * ( φ )^4 / 2 = s^3 * ( 15 + 7 * sqrt(5) ) / 4|
|volume of regular icosahedron with edges of length s||s^3 * 5 * sqrt(2) * (φ)^2 = s^3 * ( 3 + sqrt(5) ) * sqrt(2) * 5 / 2||
s^3 * 5 * (φ)^2 / 6
s^3 * ( 3 + sqrt(5) ) * 5 / 12
(where φ = (1 + sqrt(5))/2 = the golden ratio ).
Often we want to approximate a sphere by a few points (the vertices of a polyhedron) or by a few pieces of paper (the gores of a globe).
The opposite problem is #sphere_packing.
See also #map_software for more map projections.
[FIXME: Does that source code, when executed, give exactly the same results listed by Hardin et al ?: ]
``Tables of Spherical Codes with Icosahedral Symmetry: A library of good packings, coverings and maximal volume arrangements of points on the sphere in 3 dimensions having icosahedral symmetry. The number of points ranges from 60 to 78032.'' by R. H. Hardin, N. J. A. Sloane and W. D. Smith http://www.research.att.com/~njas/icosahedral.codes/ (includes source code) For each of these point listings, if I draw the voroni cell around each of these points (dividing the sphere into little hexagons and pentagons), or simply draw lines between each point and ``enough'' nearest neigbors until the sphere is divided up into little triangles, those spherical (but nearly flat) polygons become a (nearly ?) regular tiling of the sphere.
Todo: use this idea to convert a map of Earth into little tiles (Which source code makes this easier to do ?) ... then what ? Simplest thing to do: Just print out the tiles, and assemble into a nearly-spherical polyhedron. Next-simplest: Print out *several copies* high-resolution version of the tiles, spread them out on my kitchen table, and play with my ideas of tiling the sphere onto the plane, and different ways to flatten pieces of the sphere with little distortion. (In particular, long, narrow slivers flatten with little distortion ...) Perhaps I could come up with a completely different ``more accurate'' map of the Earth. [FIXME:]
[FIXME: Think about extending this to 4 or more dimensions. Would this have any practical use ? ... how about covering the surface of the 4D object ``the surface of Earth from 0 A.D. to 2020 A.D.'', which is a cylinder in some projections ? Or we could warp it to fit (half of) a hypersphere, where one pole represents the 2 initial humans (Adam and Eve), and we map ``time'' radially from that pole, such that any one instant is mapped as a 3D sphere, with area proportional to # of humans alive at that instant ]
Although Kahan writes these in terms of sin, cos, etc., the haversine simplifies one formula.
haversin(theta) = (sin(theta/2)^2.
archaversine(x) = 2*arcsin( sqrt(x) ).
(while haversin(theta) is symbolically also equal to (1-cos(theta)/2, numerical calculations using that formula give poor results for small theta).
v(theta-Theta, phi, Phi) := archaversine( haversine(phi-Phi) + cos(phi)*cos(Phi)*haversine(theta-Theta) ).
w(theta-Theta, phi, Phi) := 2*arctan( sqrt(q/r) ), where t := (tan((theta-Theta)/2))^2 p := (tan((phi-Phi)/2))^2 P := (tan((phi+Phi)/2))^2 q := (P + t + 1)*p + t r := ((p+1)*t + 1)*P + 1.
Formula v is the famous haversine formula. Kahan points out that forumula v "loses almost half the figures carried when v nears π."
Kahan says formula w "conserves almost all the arithmetic's accuracy for all valid angles input in radians, for which no (tan...) can be infinite. For angles in degrees use" if (p+P+t == infinity) then result = 180 degrees - phi - Phi else result = 2 arctan( sqrt(q/r) ).
For the angle between two vectors A and B specified in Cartesian coordinates, Kahan suggests using
angle(x,y):= 2*arctan( abs( A*abs(B) - abs(A)*B ) / abs( A*abs(B) + abs(A)*B) ).
In 3D, abs(A) = sqrt( A.x^2 + A.y^2 + A.z^2 ).
I've been thinking about building my own globe. Rather than approximating it with some sort of polyhedra made of flat polygons, I've been thinking about approximating it out of pieces of paper that are curved. (Unfortunately, paper can only curve in one direction ... which is what makes "map projection" so difficult -- the globe is not a developable surface ). Perhaps the intersecting cylinders illustrated by Paul Bourke would be much better than the standard thin globe gores.
filling space with a bunch of spheres, or filling some area with a collection of circles (possibly unequal-sized).
[2004-01-24:DavidCary I moved this from http://rdrop.com/~cary/html/3d_design.html#maps to http://visual.wiki.taoriver.net/moin.cgi/EarthMap ; this is now an old archive]
(and a few of the most interesting paper maps ... should I split out paper maps into their own category ?) (also photographs of Earth, Luna, and other planets)
Hydrographic Surveys Hydrographic surveys are conducted to determine the configuration of the bottoms of water bodies, especially as it pertains to navigation. This includes the detection, location and identification of wrecks and obstructions primarily through the use of side scan sonar and multibeam sonar technology. Using this technology, NOAA played a crucial role in finding the wreckage of: TWA 800, John F. Kennedy, Jr.'s plane and EgyptAir 990;, Electronic Navigational Charts, etc. NOAA began its release of prototypes of digital vector ENCs for testing and evaluation by the public. The ENCs are available solely via the Internet at no cost to any interested party seeking to download this data.
David Rumsey Historical Map Collection ... contains over 8,000 maps. The collection focuses on rare 18th and 19th century North and South America maps and ... The collection can be used to study genealogy and family history.http://www.davidrumsey.com/ [FIXME: what kind of software do they use ? Is there an open-source alternative ?]
DAV bought some nice maps from these people in 2001-02-20; the mailing label says
RealEarth GlobeMaps Universal Marketing Company 1013 Barrington Oaks Place Roswell GA 30075-4790
[FIXME: merge with other heading of same name]
ready-to-run mapping software; and (non-image) raw map data. See #sphere_approximation for other "projections" and other ideas and algorithms that might be useful for mapping software
finding interesting places on Earth
"Take our fun online quiz to find the best places to live, work, & retire. Discover perfect hometowns rated to match YOUR unique interests. Compare the best cities and small towns with free colorful reports. Then search for jobs in your career field in your Top Spots."
Sean Gorman ...
... Gorman has become part of an expanding field of researchers whose work is coming under scrutiny for national security reasons. His story illustrates new ripples in the old tension between an open society and a secure society.
... "It's a tricky balance," said Michael Vatis, founder and first director of the National Infrastructure Protection Center. ..."But I don't think security through obscurity is a winning strategy."
Gorman compiled his mega-map using publicly available material he found on the Internet. None of it was classified. His interest in maps evolved from his childhood, he said, because he "grew up all over the place." Hunched in the back seat of the family car, he would puzzle over maps, trying to figure out where they should turn. Five years ago, he began work on a master's degree in geography. His original intention was to map the physical infrastructure of the Internet, to see who was connected, who was not, and to measure its economic impact.
... "I wasn't even thinking about implications."
The implications, however, in the post-Sept. 11 world, were enough to knock the wind out of John M. Derrick Jr., chairman of the board of Pepco Holdings Inc., which provides power to 1.8 million customers. When a reporter showed him sample pages of Gorman's findings, he exhaled sharply.
"This is why CEOs of major power companies don't sleep well these days," Derrick said, flattening the pages with his fist. "Why in the world have we been so stupid as a country to have all this information in the public domain? Does that openness still make sense? It sure as hell doesn't to me."
... perhaps link to "transparent society", ways to make society open *and* secure.
there are an infinite number of spherical spaceforms, including the lens spaces and the fascinating Poincaré space. ...
The authors give the construction and complete classification of all 3-dimensional spherical spaces, and discuss which topologies are likely to be detectable by crystallographic methods. They predict the shape of the pair separation histogram ...
The authors are Jean-Pierre Luminet (DARC/LUTH, Observatoire de Paris, France), Roland Lehoucq (Service d’Astrophysique, CEA Saclay, France), Jean-Philippe Uzan (Laboratoire de Physique Théorique, Orsay, France), Evelise Gausmann (Université de Sao Paulo, Brésil) et Jeffrey Weeks (Canton, USA).
There would also need to be legal changes. In the UK, for example, automatic control of steering and brakes is illegal.
Canadian engineer Paul Moller's Skycar M400
skyhooks, space elevators, beanstalks, etc.
also Loftstrom loops.
Designing a skyhook has some similarities to #spacecraft_design , yet in other ways it's completely different than any artifact ever built before.
"space elevator" appears stationary (perhaps with minor vibrations) to someone standing on Earth (or whatever planet it is installed on). The "skyhook" appears to spin; typically one end comes down to (near) the planet surface, grabs the cargo, then pulls back out ... and releases it somewhere out in space. "rotavators, which are basically rotating shorter space elevators in lower orbits"
[... You'd think, for example, that the strongest fibers would be polyethylene, which is just long carbon chains. It turns out that a large part of the strength of stronger materials (e.g. nylon, Kevlar) is the side groups that keep the chains from slipping past each other. There are a lot of tensility vs shock resistance vs brittleness issues that mean that there isn't any one best, or even "strongest", material. --JoSH]
Tethers Unlimited, Inc. (TUI)http://tethers.com/
Tethers Unlimited, Inc. (TUI) is a research and development company specializing in advanced space technologies and scientific computing solutions. TUI was founded in 1994 by Dr. Robert P. Hoyt and Dr. Robert L. Forward to develop products based upon space tether technologies.seems to be doing a lot of 5 Km tethers ...
points to some reference materials about building a beanstalk.
start of space has been variously defined, however NASA currently defines it as
an altitude of 60 miles. Anyone who manages to attain an altitude of 60 miles
is designated by NASA to be an astronaut.
Andrew M. Sopchak 2002-07-26
"Edwards' estimated costs for putting up the first elevator are in the $40 billion range - considerably less the than the world's economic production." -- ???
the International Space Station (ISS). ...
last year or so, a report came out that indicated
the ISS was going to chew through 100-150 billion USD.
For those with long memories,
you may recall that the price tag for the ISS was as low as 4 billion USD in the 80's.
Part of the problem is that you get incremental budget overflows
(plus many, many missed deadlines) with these large projects.
A nice intuitive way to express the strength to weight ratio of a material is called "characteristic length". It is the length of material fashioned into a constant cross-section rope that can just support itself when hung from one end in a uniform one earth gravity field. (The formula is tensile-strength/(density*1g)). ...
Later editions of the CRC handbook [ book.html#crc_press ] have a NASA originated table labelled "Mechanical and Physical Properties of Whiskers". The indicated whiskers are actual laboratory grown, millimeter length, single crystal rods of various substances, whose strength and density can be measured. The measured properties give the following characteristic lengths:Graphite whiskers 961 km Al2O3 whiskers 527 km Iron whiskers 162 km Si3N4 whiskers 455 km SiC whiskers 704 km Si whiskers 337 km
... By comparison we have todays engineering materials:Bulk aluminum 10 km Bulk iron 11 km Bulk steel 40 km Nylon 88 km Fiberglass 98 km Kevlar 195 km
... Mars is the best nontrivial place in the solar system to build a synchronous skyhook, since it both rotates quickly, and has a shallow gravity well. Any kind of skyhook for Mars can be made of steel, and is a piece of cake with Kevlar.
[DAV: note that the distance from Earth's surface to geosync is an altitude of 35 786 Km, and that because earth's gravity decreases with distance and cables can be engineered with taper, the above distances are very pessimistic. ]
[DAV: the distance from the Moon's surface to its geosync (lunar-sync ?) orbit is (from its mass and rotating once a month) an altitude of about 92 000 Km; about 1/4 of the Mean Earth-Moon distance of 384 401 km. This is for a space elevator pointing out at some random direction from the Moon's equator. But if we align it directly towards or away from the Earth (i.e., right through the L1 or L2 Lagrange points), ... it seems intuitive that we need the center of mass at the Lagrange point, only 50 000 Km from the surface of the moon ? ]
"Using Mechanosynthetic Assemblers to Build an Orbital Tower" by Jerome D. Rosen 1995-04-04 http://www.islandone.org/MMSG/9601-news.html#RTFToC46
From: "Scott Jensen" Subject: Re: Space Elevator Date: 03 Nov 1999 00:00:00 GMT Newsgroups: sci.nanotech ... It was first conceived by Yuri Artsutanov in 1960 in Russia. Arthur C. Clarke wrote about it in his book "Ascent To Orbit: A Scientific Autobiography" (John Wiley & Sons, 1984) in chapter twenty-one "The Space Elevator -- And Beyond". The chapter is nothing more than a short introduction for a paper that appeared in "Advances in Earth Orientated Applications of Space Technology" (Vol. I, no. 1, 1981, pp. 39-48), but I'm guessing you'll have a better chance of getting hold of Clarke's book thus why I gave it. ... The material Artsutanov suggested for using only existed in microscopic quantities. On the bright side, we'd only need 900 tons of it. Sorry, I forget what was the material he proposed using. However, if the manufacturing of it could be solved, then yes the space elevator could be easily constructed. ... > ...and is not likely to in the near > future. The only materials even theoretically capable of doing the job > are things like single-crystal (gem quality) diamond 80 thousand miles long! What? Carbon crystals have breaking lengths of up to 3000kms. A "to-sea-level" space elevator would "only" need to be 5000km long. ... > Not to mention the > transportation system to get a trillion tons into geosynchronous orbit. No one proposes using Earth materials. It is either asteriods or lunar. Probably lunar. Oh, as a side note, we can make a space elevator for the Moon using mere steel. What many propose is first using mass drivers to create the lunar space elevator then use the lunar space elevator to send up the material to make the Earth space elevator. Scott
serious design proposals. spaceships, Dyson spheres, Ringworld, space stations, ...
see also #skyhook
These are pretty long-term designs. For already-implemented and near-term designs, see Orbital Mechanics astro_links.html#orbit .
see also design in general.
see nanotech.html for a promising manufacturing technique.
[FIXME: comb out the skyhook info, make separate skyhook section] [FIXME: comb out satellite info, move to Orbital Mechanics]
[FIXME: compare to http://c2.com/cgi/wiki?MatrixTemplateLibrary and to
A good C++ library: NTL provides data structures and algorithms for manipulating signed, arbitrary-length integers; and for vectors, matrices, and polynomials over the integers and finite fields. ... http://www.shoup.net/ntl/ ...
Engineering Design Process for Satellites Step 1: Identify the problem. Step 2: Create criteria. Step 3: Design your satellite's subsystems. Step 4: Decide what instruments will make up your satellite's payload. Step 5: Optimization. Step 6: Draw a blueprint of your design. Step 7: Name your product.
NASA cybercrime investigators are looking into the theft of militarily significant design documents pertaining to the next generation of reusable space vehicles.
The documents, which are restricted under current export laws from being shared with foreign nationals or governments and are also strictly controlled under the International Trafficking in Arms Regulations (ITAR), were obtained by Computerworld from a hacker who claims to be based in Latin America.
When asked how easy or difficult it is to crack into NASA systems, a hacker by the nickname Hackah Jak, a member of the defacement group known as Hackweiser, replied, "Who hasn't hacked NASA?"
John Pescatore, an analyst at Stamford, Conn.-based Gartner Inc., said the disclosure of the documents on the Internet is "a very bad thing," ...
``GPS Guidance for Projectiles'' article by Lawrence L. Wells 2001-10-01 in _GPS World_ http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=1806
" Gun Hardening
A major advantage of modern technology is the small size -- and, therefore, low mass -- of components such as application specific integrated circuits (ASICs). Also, ball grid array mounting of digital devices, with high input/output pin count, results in a dense, low-cost, and very strong component mount. Taken together with proper layout and packaging, many of the receiver components will survive gunfire shock without additional support.
Epoxy bonding is used where additional strength is needed. Figure 2 shows an epoxy serpentine underfill, which greatly increases the shear strength of the component mount. In some cases, the mounting will survive but the component is sheared from its base by the shock. Figure 3 shows the solution in that case: an epoxy dam to support the component.
... A projectile typically receives all its kinetic energy for flight from the gun charge. ...
Low Power Consumption
... Each component in the design was selected with power consumption as the number two selection criteria (recurring cost being the first criteria). "
This article mentions ``15-kilogram acceleration''; I suspect this is a typo -- did Wells mean 15 000 gee launch acceleration ? [low power]
-- recc. Ed Nisley [FIXME: book recc]
Don't read _Set Phasers on Stun and Other True Tales of Design, Technology, and Human Error_ by Steven Casey (Aegean Publishing, 1993; ISBN 0-9636178-7-7) near bedtime.
Molecular Manufacturing Shortcut Group A Chapter of the National Space Society http://www.islandone.org/MMSG/
Implications of Molecular Nanotechnology Technical Performance Parameters on Previously Defined Space System Architectures http://nano.xerox.com/nanotech/nano4/mckendreePaper.html by Thomas Lawrence McKendree. More details at SYSTEM ARCHITECTURES FOR SPACE SYSTEMS USING MOLECULAR NANOTECHNOLOGY http://www.islandone.org/MMSG/McKendreeThesis95/PhdRsrchProp.html by Thomas L. McKendree
M2P2 would generate a magnetic field and then inject plasma (ionized gas) that would drag the magnetic field lines out and form a plasma bubble 30 to 60 km in diameter.
This is similar to the Earth's magnetic field trapping a large volume of electrified gas - thus forming the magnetosphere - and forcing the solar wind to flow around it.
With a bottle of just 3 kg (6.6 lb) of helium as the plasma fuel, the magnetic bubble could be operated for three months. The size of the bubble would expand and contract with variations in the solar wind, so the force on the 100 kg spacecraft would stay constant at 1 Newton (about a quarter of a pound). The 3 kilowatts of electricity to run the magnet and plasma generator would come from solar cells.
There is enough power in the solar wind to accelerate a 136 kg (300 lb) spacecraft to speeds of up to 288,000 km/h (180,000 mph) or 6.9 million km (4.3 million mi) a day.
If launched in 2003, M2P2 would go past the heliopause, where the solar wind runs into the interstellar wind, by 2013. That's a distance of more than 150 times the distance from the sun to the Earth. Voyager 1, launched in 1977, will get there in 2019.
Winglee said that adding dust particles to the magnetic bubble would enhance the thrust, and accelerate the M2P2 even faster for a mission to another star.
Nigel C. Eastmond <nce at liv.ac.uk> 1995-11-29
Subject: Re: Most Beautiful Sci-Fi Ships Ever (Poll)
Are you chaps totally forgetting about Dune? What about those amazing cylinders with the ornate door that you drive oodles of funny rhomboids though? They were pretty nice. Mind you, when you consider that Star Wars was a long time ago in a galaxy far away and that Star trek was only a few hundred years in the future, the timeline for Dune means that the Spice- sucking Squids of the Spacing Guild were a damn-sight more advanced than any half-mad Emporer-type with bad teeth and thousands of years ahead of the insane shipmates of the Enterprise, boldly going into God knows what.
Darth Vader used to order "Prepare for hyperspace". Kirk, Picard et al. would call "Ahead Warp Factor 2". Didn't they realize that with a bit of cosmic origami, that the damn stuff could be FOLDED? All you have to do is get tripped out on some damn expensive shit from Arrakis and off you went. You could design ANYTHING to fly like that. It didn't have to look like metal cowpat (Millenium Falcon) or a gigantic water pistol (Rebel frigate). You could really go to town with lots of gilt and stuff. Cool!
From: dietz@Computerese.Information.Network (Paul Dietz) Newsgroups: sci.space.science Subject: Re: Ion drive Date: 24 Nov 1995 03:50:48 GMT Organization: Computerese Information Network (CIN.net ) Lines: 20 Return-Path: firstname.lastname@example.org To: email@example.com Joshua B Hopkins (firstname.lastname@example.org) wrote: : In choosing a propellant for an ion drive, you want to look at two major : issues. The energy required to ionize the propellant must be fairly low, : otherwise you spend too much energy ionizing the fuel and not as much : accelerating it. Generally, heavier atoms/molecules are desireable, : because while they decrease the Isp, they increase the thrust. Heavier atoms/molecules do not necessarily decrease Isp, because you can just increase the voltage in proportion to the mass/charge ratio of the ions. The real reason to go to high mass/charge ratio particles is the effect on thrust density. There is a limit to the current density in ion engines due to the space charge of the ions. At fixed exhaust velocity, thrust density goes as the square of the mass/charge ratio. Paul
see astro_links.html for some related devices that have already been put in space.
see lunh2o.html for info on the Lunar Prospector. satellite
siege engine enthusiasts
Cheap paper bags of flour make fun projectiles ... Trebuchets do their best work with standardised uniform projectiles, but an awful lot of Quasimodo's output was so frivolous you'd have to call it "Comic Relief". Basically, if it looked like you could hurl it, we hurled it. If it looked like you couldn't hurl it, we still tried.
What exactly is the complicated multi-pulley-like contraption one sees attached to the top of the throwing arm on the trebuchet by Mr. Doucleff and the trebuchet that Mark uses while playing AOE ? Doucleff doesn't explain anything (why should he ? he has a trebuchet !) and the Radlinski trebuchet apparently doesn't have this feature. Does this optional feature really help improve range ? David Cary is almost tempted to build his own and find out.
$49.00 plus Shipping and Handling. "Tabletop Trebuchet kit" is reviewed by Dan http://www.dansdata.com/treb.htm .
Anybody with some wood glue, a couple of seven inch clamps and the ability to build a Lego kit should be able to put the treb together in a few hours, not counting glue-drying time. ...
Firing a little treb is easy, because you don't have to worry about killing people ...
Anyone who builds a trebuchet is just a teensy bit scary link_farm.html#people_that_scare_me .
Sounds like an interesting concept.
TRIZ leads engineers to generate potential solutions at a much faster rate than mere brainstorming would. ... Altshuller ... is more the Charles Ives of science than an early venture capital cowboy. Just as Ives refused to copyright his musical compositions, Altshuller always insisted that his ideas remain in the public domain, say those who knew him, and he was not particularly happy when TRIZ's stateside commercialization began. "Altshuller said TRIZ is not for this," says Zlotin. "TRIZ should be only for all human beings to get." Now chief scientist at Ideation International, a TRIZ consultancy, Zlotin describes Altshuller as "Communist, but not idiotic Communist like people who like power. He was Communist in the sense of Jesus Christ; he wanted to make, for all people, something good." ... Though Altshuller was freed after Stalin's death in 1953, it would be several more years before he felt safe in publishing his theories. To support himself in the meantime, he turned to writing science fiction, under the pen name Genrich Altov. English translations of three of Altshuller's stories, collected in a book called "Ballad of the Stars," reflect not only Altshuller's views of the inventive process but his struggle to maintain his scientific faith amid crushing adversity and solitude. Science fiction, to Altshuller, was more than just a way to put bread on the table. Despite the fact that the ideas contained in sci-fi tales are often completely outlandish, as he writes in his exegesis of TRIZ, "The Innovation Algorithm," they remain useful for catalyzing research and inventiveness: "SF helps overcome psychological barriers on the road to [the] 'crazy' ideas without which science cannot continue its development." Altshuller even went so far as to catalog these concepts in a "Registry of Contemporary Science Fiction Ideas." ... "In many ways, the ability to ask the right questions is more powerful than the ability to answer them," says inventor Levy. "It's the difference between knowledge and wisdom."
Some nifty theorems regarding what David Cary calls the "triangle function" t(x).
LATE BREAKING NEWS: I've just discovered that what I call t(), others call "sigmaI": "sigmaI which is like factorial but adds instead of multiplies".
Dr. Math uses T(n) notation for Triangular Numbers http://mathforum.org/dr.math/faq/faq.number.glossary.html#triangular
[FIXME: is there a better place to put my geometry ramblings ?]
o 3 o o
o 6 o o o o o
o 10 o o o o o o o o o
o 15 o o o o o o o o o o o o o o
o 21 o o o o o o o o o o o o o o o o o o o o
o 28 o o o o o o o o o o o o o o o o o o o o o o o o o o o
o 36 o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
a*b = t(a+b) - ( t(a) + t(b) ).
For example, to multiply 5*3, first arrange a triangle of size t(a+b) = t(8) = 36 oranges:
o 36 o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o
Crossing out t(3) = 6 oranges at the top, and t(5) = 15 oranges on the right, leaves only
x x x x x x o o o x o o o x x o o o x x x o o o x x x x o o o x x x x x 5*3 = 15 remaining oranges.
The Babylonians also defined multiply in terms of a unary function x^2:
a*b = ((a + b)^2 - a^2 - b^2)/2
a*b = (a + b)^2/4 - (a - b)^2/4
These look very similar to my definitions of multiply:
a*b = t(a+b) - ( t(a) + t(b) )
a*b = (t(a+b) - t(a-b) - b) / 2 (2002-12-03:DAV: discovered a*b = (t(a+b) - t(a-b) - b) / 2 after playing with the formulas I found on the Anne Veling page)
The so-called "square" function x^2 can also be defined in terms of t(x): x^2 = t(x) + t(x-1). The square function has nothing to do with the square shape -- let me try to give an example. Take *any* shape whatsoever, (say, a life-size statue of a giraffe). Scale it up and make a new statue of exactly the same shape, except x times bigger. In other words, make the nose-to-tail distance x times bigger, the hoof-to-shoulder distance x times bigger, the breadth across the shoulders x times bigger, etc. Inevitably, when a shape is properly scaled, every other 1D measure -- even the ones you didn't actually measure when you made this new statue -- all have x times the corresponding measurement of the original. For example, the circumference of the widest part of the belly, or the length up one leg and down the other. Then the area (cross sectional area, surface area, or any other 2D measure) of the new statue now has x^2 its original measurement. That's what the "2" part means -- 2D. Any 3D measurement on this statue (say, the volume of the smallest box you can pack the statue into, or the volume of water displaced when the statue is submerged) now has x^3 times the corresponding measurement on the original statue. Some mathematicians like to play with 4D shapes -- can you guess how the 4D "hypervolume" of a 4D object compares to one x times larger ? Some very pretty shapes have a measurement that scales to a fractional power like x^1.5 -- these are called fractals.
If you look carefully at these single-layer triangles of oranges, you can see the little triangular gaps between them. But if you stack 2 layers of oranges, that fills in the gaps. If you squash these 2 layers down to 2D, the oranges become triangular and cover the entire area:
+ / \ / b \ b = orange on bottom layer +-----+ / \ t / \ t = orange from top layer / b \ / b \ squashed down into the gaps on the bottom layer. +-----+-----+ / \ t / \ t / \ / b \ / b \ / b \ +-----+-----+-----+[FIXME: make some pretty drawings of oranges in 2 layers here -- I think bright orange on a black background would be pretty].
If you take some oranges (or marbles, or whatever you have handy) and stack them in 2 layers like this, compare how long one side of the triangle gets (counted in oranges) vs. how many total oranges are in these 2 layers. We have
+ / \ / b \ +-----+ length = 1 total: 1 orange + / \ / b \ +-----+ / \ t / \ / b \ / b \ +-----+-----+ length = 2 total: 4 oranges + / \ / b \ +-----+ / \ t / \ / b \ / b \ +-----+-----+ / \ t / \ t / \ / b \ / b \ / b \ +-----+-----+-----+ length = 3 total: 9 oranges + / \ / b \ +-----+ / \ t / \ / b \ / b \ +-----+-----+ / \ t / \ t / \ / b \ / b \ / b \ +-----+-----+-----+ / \ t / \ t / \ t / \ / b \ / b \ / b \ / b \ +-----+-----+-----+-----+ length = 4 total: 16 oranges ... length = x total: x^2 oranges
As you can see, there is a triangle of t(x) oranges on the bottom layer with x triangles on an edge. Then there is a slighly smaller triangle of t(x-1) oranges on the top layer with (x-1) triangles on an edge. So
x^2 = t(x) + t(x-1).
You can see that if we double (x=2) the edge length of *any* triangle of oranges, no matter how many oranges that may be,
+ / \ / \ original trangle made up of any number of oranges +-----+ + / \ / \ +-----+ new bigger triangle / \ / \ / \ / \ +-----+-----+
this new triangle now has x^2 = 2^2 = 4 times as many oranges as the original. [FIXME: draw a picture of just setting 4 copies of the original triangle of, say, 9 oranges. Then show another picture after you then flip the central triangle over, and another showing how the oranges all fit together *without* squashing, and without gaps. The central triangle has flipped top and bottom -- it has t(x) oranges on the top and t(x-1) oranges on the bottom. This makes a continuous, smooth top area. ]
We've already shown that x^2 = t(x) + t(x-1). (b)
The previous 2 equations can be shuffled to show that
x*(x+1)/2 (commonly seen in some non-triangle-aware equations)
= (x^2 + x)/2 (distribute)
= (t(x) + t(x-1) + x)/2 (using property (b))
= ( t(x) + t(x) )/2 (using property (a))
= t(x) (halve above and below fraction bar)
When you see x*(x+1) or (x^2 + x) in some equation, more than likely triangle geometry can simplify things (by replacing x*(x+1) == (x^2 + x) with 2*t(x), then trying to figure out *where* a triangle of size t(x) exists in the situation that equation describes ).
c == [ (a+b)^2 + 3*a + b ]/2 c == [ a^2 + b^2 + 2*a*b + 3*a + b ]/2 c == [ a^2 + b^2 + 2*a*b + 3*a + b ]/2 we recognize the pattern "(x^2 + x)/2 = t(x)", usually a clue that triangles will be helpful, and convert to triangle notation: c == [ (a^2 + a)/2 + 2*a/2 + (b^2 + b)/2 + 2*a*b/2 ] c == (a^2 + a)/2 + a + (b^2 + b)/2 + a*b c == t(a) + a + t(b) + a*b Next we substitute the definition of multiply, a*b = t(a+b) - ( t(a) + t(b) ) to get c == t(a) + a + t(b) + t(a+b) - ( t(a) + t(b) ) Lots of terms cancel out, and we are left with c == a + t(a+b). To recover the original 2 values from c, we merely find the largest triangle we can build from c oranges, which has sides of length L = (a+b). Then we count the "a" leftover oranges, and we calculate b = L-a. We know that c must have come from a single unique pair of whole integers (a,b), since a < a+b+1 a + t(a+b) < t(a+b) + a+b+1 a + t(a+b) < t(a+b+1) . In other words, no matter how many "leftover" oranges a we have, it's never enough to build a triangle even 1 row larger. Unfortunately, there are multiple (a,b) pairs where b is a integer, but a is some real number, that map to the same value c. For example, b = 1, a = 1.772, c = a+t(a+b) = 7 b = 2, a = 1.000, c = a+t(a+b) = 7
[FIXME: tilings are generally thought of as 2D ... so move to the rest of my 2D stuff at machine_vision ? ... but DAV is interested in tiling 3D objects, in particular the sphere.]
``What is a tessellation? A tessellation is a pattern formed by the repetition of a single unit or shape that, when repeated, fills the plane with no gaps and no overlaps.''
c c c c c c c a a a c c c c e e e a a a a c c c e e e e a a a a D D D e e e e a a a D D D D e e e b b b D D D D f f f b b b b D D D f f f f b b b b f f f f b b b f f fThe area of each region is identically 14 dots (perfect, since we want equal areas in our 2D barcodes ). (2 kinds of regions alternate in vertical stripes) each region is rotationally (x2) symmetric about its centroid (nice, I suppose it's adequate approximation to desired hexagon/circle), and center-to-center distances in vertical direction are all 4, center-to-center distances in other directions ("diagonally") are all exactly sqrt( (3.5)^2 + 2^2 ) =~= 4.03 (almost exactly the ideal 4.0), and center-to-center distances horizontally are 7 pixels ( giving a vertical/horizontal ratio of 7/4 = 1.75, almost identically the perfect vertical/horizontal ratio for packed spheres of sqrt(3) =~= 1.73 ).
This was derived from
c c c c c c a a c c c c e e a a a a c c e e e e a a a a D D e e e e a a D D D D e e b b D D D D f f b b b b D D f f f f b b b b f f f f b b f f
where each region is *exactly* the best possible appproximation in 12 dots to a circle, center-to-center distances in vertical direction are all 4, center-to-center distances in other directions (diagonal) are sqrt(3^2+2^2) =~=3.61. and center-to-center distances horizontally are 6 pixels, giving a horizontal/vertical ratio of 6/4 = 1.5, as opposed to the perfect v/h ratio for packed spheres of sqrt(3) =~= 1.73. This would be ideal if your printer printed dots just *slighly* taller than they are high, with a aspect ratio of sqrt(3) / (6/4) =~= 1.155.
A smaller (but less "round") mapping of hex grid on square dots is
c c a a c c e e a a D D e e b b D D f f b b f f
where each region is the best possible approximation in 4 dots to a circle, it's very symmetric, center-to-center distances in vertical directions are 2, center-to-center distances in other directions are sqrt( 2^2 + 1^2) = 2.24, and center-to-center distances vertically are 4 pixels, giving a vertical/horizontal ratio of 4/2 = 2, as opposed to the perfect v/h ratio for packed spheres of sqrt(3) =~= 1.73. This would be ideal if your printer printed dots just *slighly* narrower than they were tall, with a aspect ratio of (4/2) / sqrt(3) =~= 1.155. (Hm; same as 12-point grid ?)
Of course, the smallest mapping of hex grid on square dots is
c a c e a D e b D f b f
also known as a bricklayer's layout, where each region is 2 dots. This is same as squares above except squashed in vertical direction by a factor of 2. A vertical/horizontal ratio of 2/2 = 1, as opposed to the perfect v/h ratio for packed spheres of sqrt(3) =~= 1.73. This would be ideal if your printer printed dots wider than they were tall, with a aspect ratio of sqrt(3) / 1 =~= 1.732.
Here are some more mappings of a hex grid onto square pixels:
c c c c c c c c a a a c c c c e e e a a a a c c e e e e a a a a D D e e e e a a a D D D D e e e b b b D D D D f f f b b b b D D D D f f f f b b b b f f f f b b b f f f
Every region is the same shape and size (14 pixels) (but rotated in all 4 directions) , no single-pixel protuberances.
b b b b b b b b
This region is exactly the best possible approximation in 8 dots to a circle. But, there's more than one way to pack these shapes. Once a 45 degree diagonal is packed, each parallel stripe can be shifted into one of 2 positions -- either precisely horizontally aligned with the region to the left, a flattened version of the 12-dot regions above, or shifted so there's a region exactly one pixel above and another 1 pixel below the region to the left, which seems to be more symmetric ...).
D D D D D D a a D D g g a a a a g g g g a a E E g g E E E E b b E E F F b b b b F F F F b b c c F F c c c c c cPacket like a squashed version of the 12-dot "cross" region above. Center-to-center distances in the (2) horizontal direction are all 4. Center-to-center distances in the (4) diagonal directions are all sqrt( 2^2 + 2^2 ) =~= 2.83. Center-to-center distances in the vertical direction are also 4 (much too small), giving a horizontal/vertical ratio of 4/4 = 1 (a perfect approximation to square rhomboid). This would better match the ideal the perfect v/h ratio for packed spheres of sqrt(3) =~= 1.73 if the pixels were much taller than they are wide, with an aspect ratio of sqrt(3) =~= 1.73.
D D D D D D g g a a D D g g g g a a a a E E g g a a E E E E b b E E b b b b F F b b F F F F c c F F c c c c c c
The same shape, but a more symmetric packing -- moving the furthest-away-touching region a bit closer, which pushes one of the closest-touching regions a bit further away. Center-to-center distances in the (2) lower-left-to-upper-right diagonal direction are sqrt( 2^2 + 2^2 ) =~= 2.83, as in the previous tile. But the other 4 regions touching a given region (2 to upper left, 2 to lower right) have a center-to-center distance of sqrt( 1^2 + 3^2 ) = 3.16. It's not really symmetric around the horizontal or vertical axis, so adjusting printer pixel ratio won't help much. It's more symmetric around the lower-left-to-upper-right diagonal. The upper-left center-to-center distance is sqrt( 4^2 + 4^2 ) = 5.66, which is just a bit too large. the UL/UR ratio is sqrt( 4^2 + 4^2 ) / sqrt( 2^2 + 2^2 ) = 2, just a little larger than the perfect v/h ratio for packed spheres of sqrt(3) =~= 1.73. If we could stretch the pattern in the lower-left-to-upper-right direction (or shrink it in the lower-right-to-upper-left direction), then we could place the region centroids at exact hexagon centers.
[FIXME: draw pictures of these with more contrasty colors ? ]
a c c c e a a a c e e e b b b D f f f b D D D f ...
Each triangle maps onto 4 pixels, which can be thought of as (slightly distorted) triangular pixels
+ / \ / a \ ==== +--+ +-----+ | a| / \ c / \ ==== +--+--+--+ / b \ / d \ |b | c| d| +-----+-----+ +--+--+--+
The maximum possible density for length-3 slash codes is to pack them into 5 pixel cells, like
a a a a c b a c c c e b b b D c e e e b D D D f e D f f f for
b b b c c a b a b c a x c x c a a x x x
When David Cary heard about the dot-loss problem (very small dots fall off the paper), I developed this 2D barcode idea very similar to the slash code, but with improved "stickyness". This assumes that dots at least 5 pixels in area are just barely big enough to stay attached, and that the print/read process has enough resolution to detect single pixels.
This also has the side effect that all the information is carried in the *perimeter* of the blob. I'm told that human eyesight can distinguish differences in the perimeter better than differences in the interior. So perhaps this would make an above-average human-readable code as well.
Similar to slash code, but each blob encodes 2 bits (rather than 1 bit): the first bit encodes horizontally, x x a * * b b * * a x x where a = not(b) = encoded bit. The other bit of this blob encodes vertically, c d x * * x x * * x d c where c = not(d) = other encoded bit.
This gives 2 black pixels and 2 white pixels to each encoded bit, exactly like the (length=3 pixels) slash code.
If you're willing to give up some redundancy, you could differentially encode each bit in only 1 black pixel and 1 white pixel for each encoded bit, giving 4 bits per blob.
Or you could even make each of the 8 pixels encode a different bit. Unfortunately this means giving up on the robust differential detection pattern (you need some other mechanism to adjust the detection threshold) and it also means the total black pixels/cell is no longer a constant 8 pixels (so humans viewing it from a distance no longer see a perfectly uniform gray, but may see some clumping).
These blobs fit in a 12 pixel cell. They could be packed in a square grid, leaving 4 white pixels in the diagonal gaps between blobs (a 16 pixel cell) -- perhaps you could take advantage of the "fixed" white gaps and black centers to adjust the threshold for the 8 bit per blob encoding. This gives 8 bits of information every 16 pixels, an information density of 2 pixels/bit, slightly better than the length-3 slash code density of 5 pixels/bit.
Alternatively, these 12 pixel blobs could be packed even tighter in a hexagonal grid to cover every pixel with no gaps as show in the hexagonal example above. If one uses 8 bit per blob encoding, then there is the risk that long streams of 1 bits may cause solid black coverage over wide areas -- -- this makes it almost impossible to set threshold appropriately. One could either use the robust differential encoding for each bit ( 4 bits per blob, information density of 12/4 = 3 pixels/bit ), or use some less-robust run-length-limit to ensure at least one white reference pixel per cell (giving at least 7 bits/cell, an information density of 12/7 = 1.7 pixels/bit).
Often we want each module of a bar code to be "compact", so the foreground/background characteristics don't change much over the whole area (i.e., so we can use a single threshold per module even in the face of a linearly changing background gradient; or we can use a simple linear adjustment gradient even in the face of a non-linear background gradient). However, we also want to be able to tile (tesselate) these modules over a large area.
Also, we also want a QAM constellation to be "compact". If we spent the money to get a linear amplifier capable of getting a certain distance from the 0 point on the constellation, we might as well use *all* the points inside that constellation. [FIXME: cross link to ham radio]
Starting with a grid of pixels, I define a "circle-like object" to be a subset of pixels, such that given any pixel in the subset (or more particularly, the pixel in the subset furthest from the center point), every pixel in the grid that is the same or smaller distance from the center point is also in the subset.
(I see that Steve Waterman has extended this idea to 3D, producing Waterman polyhedra and applying some of them to polyhedral maps of Earth Waterman polyhedron: Cartography )
I know there are at least 3 kinds of circle-like objects: centered on corner of pixel, centered on middle of pixel, and centered on edge of pixel. I suspect there are other types as well, that are even less symmetric.
Some "circles" centered on center of pixel have a "sharp" single-pixel bump, which doesn't look very circular to me.
Here are all the circle-like objects of a square grid that are either centered on corner of pixel, or centered on middle of pixel, up to 81 pixels, sorted by area: (are there any that have outer pixels close to 12 sided polygon?)
Shape Pixels(area) ; pixels(perimeter) (distance from midpoint to center of outermost pixel) o 1 ; 1 tesselating oo oo 4 = 2^2 ; 4 tesselating (0.707 or less) o ooo 5; 4 tesselating o (1 or less) ooo ooo 9 = 3^2 ; 8 tesselating ooo (1.41 or less) oo oooo oooo 12 = 2^2 + 4*2 ; 8 tesselating oo (1.58 or less) o ooo ooooo 13 = 3^2 + 4 ; 8 tesselating ooo (2 or less) o oooo oooo 16 = 4^2 ; 12 tesselating oooo 16QAM oooo (2.12 or less) ooo ooooo ooooo 21 = 3^2 + 4*2 ; 12 non-tesselating ooooo (2.24 or less) ooo smallest non-tesselating circle-like object oo oooo oooooo oooooo 24: 4^2 + 4*2 ; 12 tesselating oooo (2.55 or less) oo ooooo ooooo ooooo 25 = 5^2 ; 16 tesselating ooooo the largest circle-like object that is also a perfect square. ooooo (2.83 or less) o ooooo ooooo ooooooo 29 = 5^2 + 4*1 ; 16 non-tesselating ooooo (3 or less) ooooo the smallest that has any 1:2 slopes (also has *no* 1:1 slopes) o oooo oooooo oooooo oooooo 32: 4^2 + 4x4 ; 16 non-tesselating oooooo (the common 32-point constellation for 32QAM) oooo (2.92 or less) ooo ooooo ooooooo ooooooo 37 = 5^2 + 4*3 ; 16 non-tesselating ooooooo (3.16 or less) ooooo ooo oo oooo oooooo oooooooo oooooooo 40 = 4^2 + 4*4 + 4*2 ; 16 tesselating oooooo (3.53 or less) oooo Is this the largest circle-like object that is also tesselating? oo oo oooooo oooooo oooooooo oooooooo 44 = 6*6 + 4*2 ; 20 (or only 12, if you use convex hull) oooooo the 2nd smallest that has any 1:2 slopes (also has *no* 1:1 slopes) oooooo (3.54 or less -- notice the very little difference from above) oo non-tesselating ooooo ooooooo ooooooo ooooooo 45 = 5^2 + 4*5 ; 20 ooooooo (3.61 or less) ooooooo ooooo oooo oooooo oooooooo oooooooo oooooooo 52 = 6*6 + 4*4 (has no 1:2 slopes) ; 20 oooooooo (3.81 or less) oooooo oooo o ooooo ooooooo ooooooo ooooooooo 49 = 5^2 + 4*5 + 4*1 ; 20 ooooooo the third smallest with any 1:2 slopes ooooooo (4 or less) ooooo o ooo ooooo ooooooo ooooooooo ooooooooo 57 = 5^2 + 4*5 + 4*3 ; 20 ooooooooo (4.12 or less) ooooooo ooooo ooo oooooo oooooooo oooooooo oooooooo 60 = 6^2 + 4*6 ; 24 oooooooo (4.30 or less) oooooooo oooooooo oooooo ooo ooooooo ooooooo ooooooooo ooooooooo 61 = 7^2 + 4*3 ; 20 ooooooooo the 4th smallest with any 1:2 slopes ooooooo (4.24 or less) ooooooo ooo 64 = 8^2 64QAM is unfortunately not a "circle-like object". (radius 6.36, but does not include several points closer than that). The following shows how to arrange more points into a smaller circle. oo oooooo oooooooo oooooooo oooooooooo 68 = 6^2 + 4*6 + 4*2 ; 24 oooooooooo the 5th-smallest with 1:2 slopes oooooooo the smallest with *both* 1:2 and 1:1 slopes. oooooooo (4.53 or less) oooooo oo ooooo ooooooo ooooooooo ooooooooo ooooooooo 69 = 7^2 + 4*5 ; 24 ooooooooo (4.47 or less) ooooooooo ooooooo ooooo oooo oooooo oooooooo oooooooooo oooooooooo 76 = 6^2 + 4*6 + 4*4 ; 24 oooooooooo oooooooooo oooooooo (4.74 or less) oooooo oooo oooo oooooooo oooooooo oooooooooo oooooooooo 80 = 8^2 + 4*4 ; 28 oooooooooo the 6th-smallest with 1:2 slopes oooooooooo (has no 1:1 slopes) oooooooo (4.95 or less) oooooooo oooo o ooooooo ooooooooo ooooooooo ooooooooo ooooooooooo 81 = 7^2 + 4*7 + 4*1 ; 24 ooooooooo (5 or less) ooooooooo because of the 3:4:5 triangle, ooooooooo the first to add more than 8 to the area. ooooooo The smallest with a 1:3 slope. o
Circle-like objects on a hex grid:
centered on one pixel: o 1 o o o o o +6 = 7 o o o o o o o o o o +6 = 13 o o o o o o o o o o o o o o o o o +6 = 19 o o o o o o o o o o o o o o o o o o o o o o o o o +12 = 31 o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o +6 = 37 o o o o o o o o o o o o o o o centered on corner: o o o 3 tesselating o o o o o o +3 = 6 tesselating o o o o o o o o o o +6 = 12 tesselating o o o o o o o o o o o o o o o o +6 = 18 non-tesselating (?) o o o o o o o o o o o o o o o o o o o o +3 = 21 o o o o o o o o o o o o o o o o o o o o o o o o o +6 = 27 tesselating (?) o o o o o o o o o o o o o o o o o o o o o o o o o o o o +3 = 30 o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o +6 = 36 o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o +6 = 42 o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o +6 = 48 o o o o o o (is the largest tesselating circle-like object?) o o o o o o o o o
Bonus: triangular grid.
6 unbroken equilateral unit triangles can fit in a hexagon inscribed inside a circle. But what is the area (in fractions of a unit triangle) of the little leftover circular segments? The leftovers add up to a bit more than 1 and 1/4 unit triangles. A hexagon circumscribed around a unit circle has an area equal to the total area of 8 unit triangles.
(Similarly, 4 unit squares exactly fit in a square circumscribed around a unit circle. The square inscribed in a unit circle has a diagonal of length 2*r and has an area equal to 2 unit squares. The little leftovers add up to a bit more than 1 square.)
The area of a unit square is 4/sqrt(3) unit triangles. The area of a circle A is: A = πr^2 unit squares = 4*π*r^2 / sqrt(3) unit triangles. (this is related to the "area of circle of radius r" in terms of unit triangles, as mentioned above)
The continued fraction for 4*π/sqrt(3) = [7; 3, 1, 11, 3, 1, ...] =~= 7.255197...
That continued fraction gives us the approximations of approximate number of unit-strut triangles to approximate the total area of the unit-radius circle: 7, 22/3, 29/4, 341/47, ... 7, 7+1/3, 7+1/4, 7+12/47, ...
From: email@example.com (SpyKnife) Subject: Re: Space Elevator Date: 19 Nov 1999 00:00:00 GMT Approved: firstname.lastname@example.org X-Complaints-To: email@example.com Organization: AOL http://www.aol.com NNTP-Posting-Date: Fri, 19 Nov 1999 21:09:12 GMT Newsgroups: sci.nanotech X-Psw: Cadmium 0.01 Diamondoid Solids and other nanomaterials would probably be more reliable than systems composed of active moving parts full of ratchets and computers. [Presumably this is in the context of large structures? Maybe, maybe not. Large structures that last a long time have typically overpowered the problem (forces handled, erosion, etc) with mass, like the pyramids. That's not an option for skyhooks and the like. Inert matter, no matter how strong, is subject to wear and tear; self-repairing systems can last much longer. Consider living organisms (ones not programmed to die) such as Galapagos tortoises and Sequoia trees. A stone spire the height of a redwood wouldn't last a fraction of the thousands of years they can attain. --JoSH]
some aerospace researchers are working to ... build a plane with malleable wings that bend and twist during flight. ... airplanes with flexible wings could lead more efficient and maneuverable aircraft for both military and commercial aviation.
The struts and cables of early biplane designs also led to large parasite drag, so the effects of improved span efficiency were not obvious. ... The induced drag of a multiplane may be lower than that of a monoplane of equal span and total lift because the nonplanar system can influence a larger mass of air, imparting to this air mass a lower average velocity change, and therefore less energy and drag.
the favorable interference between two wings of a closely-coupled biplane can be used to improve the section performance. ... This may help to explain the preference for biplanes in the low Reynolds number world of insects.
Wings that form closed loops, such as the ring-wing illustrated below, do not eliminate the "tip vortices" or trailing vortex wakes even though the wing has no tips. Still, the vortex drag of the circular ring wing is just 50% that of a planar wing with the same span and total lift ...
... When the horizontal extension is added to the winglet, forming the "C" shape, the circulation is extended from the winglet as well, producing a surface that is loaded downward for minimum induced drag at fixed total lift. ...
This configuration was independently "discovered" by a genetic algorithm that was asked to find a wing of fixed lift, span, and height with minimum drag. The system was allowed to build wings of many individual elements with arbitrary dihedral and optimal twist distributions. ...
... Airport and manufacturing constraints limit the span of a new large aircraft. [DAV: not a problem with small aircraft. For small aircraft, is it true that single-wing with large span is optimal ?] ...
... the boxplane achieves the lowest drag for a given span and height, although winglets are quite similar. ...
... Jones showed that with fixed integrated bending moment (a rough indicator of wing weight) winglets produced about as much drag savings as planar tip extensions. More recent analyses using more realistic weight estimation methods have yielded similar results ... For some applications, this discouraging result is not relevant since the aircraft must operate with a span constraint, ...
... it is my hope that advances in aerodynamics and other disciplines can be employed to do more than just marginally lower the cost of air transportation, but rather improve its safety and comfort.
while a variety of practical issues may indeed limit the size of aircraft, basic structural weight and aerodynamic performance considerations permit aircraft of much larger dimensions.
... Karl Bergey ... emeritus professor of aerospace engineering at the University of Oklahoma.
Bergey is building a fast, high-performance homebuilt that happens to use a Cherokee wing -- the original stubby rectangular one...
... tapered wings... offer three apparent advantages over rectangular ones. ...
- structural. ... reduces the bending moment ... at the root ...
- aerodynamic ... Induced drag cannot be eliminated, but it is at its minimum when the spanwise distribution of lift is elliptical. ...
- aesthetic. ... when the design of a wings is viewed as a commercial rather than a technological enterprise, the aesthetic argument, however insubstantial or misguided, may turn out to be the most compelling one ...
... A certain amount of material is unavoidably needed to give a wing its aerodynamic shape, ... Aerodynamic scale effect makes it possible to use a smaller rectangular wing for a given stalling speed... the tapered wing, though inherently slightly lighter, must be larger, erasing the weight saving. ...
... Whatever the shape of the wing, tapered or straight, the nature of the airflow around the wing tends to force the spanwise lift distribution toward the ideal elliptical shape...
... Tapered wings tend to stall outboard, reducing aileron effectiveness and increasing the likelihood of a rolloff into a spin. ...
The rectangular wing, on the other hand, naturally tends to stall from the root... With a couple of degrees of twist, a rectangular wing closely approaches an elliptical lift distribution and provides impeccable stalling behavior besides.
Paper airplanes are one category of functional origami #origami . See also flying robots robot_links.html#flying_robots .
see also #educational_toys and one of my favorite varieties of functional origami, #paper_airplanes . Alas, I haven't had any time recently to play with origami. I am more interested in pure geometry, and functional origami than with representational origami.
related to the bootstrap problem learning.html#bootstrap and robot replication computer_architecture.html#replication .
I've often wondered what set of mechanical tools it takes to get "closure" (in the software tools sense). I.e., say Ann has a bunch of tools in her garage, and (given a bunch of raw materials) she builds, say, a milling machine and some other tools to fill my (empty) garage. Then, with only raw materials going into my garage, I build another set of tools, and I give them and (a copy of) the plans I used to build them to Joe. If Joe -- using only (a) those tools, (b) those plans, and (c) some more raw materials -- can construct another milling machine and *all* the other tools in my garage, such that they are as good as or better than the tools in my garage, then this set of tools and plans has "closure". I'm not sure how raw I want to get with "raw materials"; maybe I'll accepts screws and bolts and sheet metal and car starter motors and a computer as "raw materials", and let other people worry about extracting iron from rocks. On the other hand, I want to be a little more sophisticated with "plans" and "tools", and try to make CNC mostly-automated tools.
I think it would be cool to load up a stack of sheet metal into a gizmo that would feed them one at a time (like a paper sheet feeder) and then when I came back the next day, I would have a pile of (possibly all unique) precisely cut sheet metal parts. -- DAV
John Bump http://www.frii.com/~katana/casting.html has already gotten pretty good at casting aluminum, and plans on building a entire milling machine and a airplane. I think this is a good start.
Nesting is the process of finding minimum waste arrangements of irregular shapes on regular stock sheets. The problem arises in a number of manufacturing applications, some of which are sheet metal fabrication, composite layup, water jet cutting, and tooling. ...
The 2NA (2-stage Nesting Algorithm) software is a set of C-language subroutines that construct approximate solutions to the 2D nesting problem. The 2NA code uses a two-stage heuristic algorithm ... Furthermore, 2NA has recently been expanded to allow "nesting in cutouts," i.e. the placement of parts inside other parts that have holes.
2-stage Nesting Algorithm (2NA) is Copyright © 2002 The Boeing Company.
-- http://www.boeing.com/phantom/2NA/ [FIXME: 2NA Polygon Simplification http://www.boeing.com/phantom/2NA/description/nesting1.html looks interesting ... ]
2003-05-29:DAV: started section on closure.
"submarine": literally, under water.
Many various devices designed to be used under water. see also "swimming robots" robot_links.html#swim
-- Morrisey http://www1.alphasmart.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=22;t=000167
As for taking electronic devices underwater with Zip-Loc bags, we used to try that with tape players while scuba diving (Great Lakes wreck diving involves lengthy stretches of decompression). They didn't leak as long as you didn't take them deeper than 15-20 feet (we'd leave them on the anchor line at 20 feet and pick them up on our way up), but the issue was hydrostatic pressure -- it'd press all the buttons and sometimes even crack the case. Headsets were easy to waterproof (you dip them in a can of the rubber goo used to put grips on tools) but short of a custom-built housing, the tape players were always a challenge. Not sure how this would apply to AlphaSmarts.
Alcatel Submarine Networks (ASN) http://www.alcatel.com.au/cable.htm owns one of the 5 modern submarine cable manufacturing facilities in the world. Their facility cost $120 million, and can manufacture over 6 000 Km of optical fibre cable per year. Supplied the 1996 JASURAUS cable between Australia and Asia. The built the cable for Cable & Wireless and MFS http://www.cwplc.com/press/1996/p96oct28.htm for the approximately £315 million London to New York cable (10 Gigabits/s) planned for 1998. [FIXME: bignums ?]
Transatlantic cable communications: "The Original Information Highway" http://www.rescol.ca/collections/canso/ lots of cool photographs and FAQs about the first successful transatlantic cable, (laid by the Niagra and the Agamemnon, starting in the center and ending at Newfoundland and Ireland, finished around 1858 August 5) earlier submarine cable attempts, and other related information. "...it would be a pity to kill the birds".
http://w2.siemens.de/infoshop/150_cd/business/u867-8.htm 1875: the "first direct transatlantic cable from Ireland to the U.S." is finished.
Some "things" don't work when they hold still, they require dynamic action.
A list of things that I've found that are counter-intuitive (at least to me). (Sometimes things that are counter-intuitive lead to counter-productive behavior).
"traffic waves: sometimes one driver can vastly improve traffic." by William Beaty
"traffic "experiments" and a cure for waves & jams" 1998 William Beaty
" we are not meaningless molecules in the flow, since our individual actions sometimes have immense repercussions for both good and for "evil." It's an important lesson, since traffic psychology is a miniature model for everyday ethical questions and especially for national and global politics." -- William Beaty
But such infuriating backups could be avoided -- at least on single lanes that don't require merging -- if just 20 percent of cars were equipped with adaptive cruise control (ACC), says adjunct physics Professor L.C. Davis. Doing computer simulations on his laptop from programs he wrote, Davis studies the origins of traffic jams and the impact that vehicles equipped with ACC have on traffic flow.
ACC detects the presence of a preceding vehicle and measures the distance as well as relative speed using a forward-looking sensor, and it automatically adjusts the vehicle speed to keep a proper range.
-- "World Resources 1992-93" http://www.ciesin.org/docs/001-233/001-233all.html
Although it might seem that reducing child mortality would increase population growth, the opposite is the case if countries also develop economically. As countries develop, they go through a process called demographic transition in which living standards are raised, child mortality is reduced, and fertility declines. This transition can be speeded by policies that promote education, health care, and use of contraceptives.
... total fertility rates in the industrialized countries have remained roughly at or below 2 during the 1980s and into 1990. (The fertility rate is the average number of children women bear in their lifetime.) ...
I find it counter-intuitive that many people in the US think that "24-hour time" is more complicated and harder to use: "we have a much simpler system here, it uses only 12 hours and am and pm." Wikipedia: military time
I find it amazing and counter-intuitive that most people (including myself), when confronted by a map that is truly more accurate than ones they've seen before, instantly feel that this ``new'' map is inaccurate, suspect, some sort of trick, etc. Why is this ? And what can cartographers do to indicate uncertainty and to guide people towards more appropriate maps ? )
It's all too easy to be tricked into thinking that one user interface is "simpler" or "more understandable" or "more efficient" than another user interface, merely because it is more familiar.
Some examples where people are suspicious of more accurate things that are different from what they are used to: "Young People Prefer "Sizzle Sounds" of MP3 Format" 2009 http://slashdot.org/article.pl?sid=09/03/11/153205 and perhaps WSPQ: world's smallest political quiz) .
Another example of someone tricked into thinking that one user interface is clunky and hard-to-use, merely because it is unfamiliar: "User Interface Design For Programmers" http://www.joelonsoftware.com/printerFriendly/uibook/fog0000000249.html by Joel Spolsky 2001
Crimes dropped when street lights were put out in two cities in the north of Sweden. Traffic was also calmer and no rise in traffic accidents. Övertorneå and parts of Haparanda was darkened for at least five months last winter, because of a dispute over energy prices. Article (in Swedish): http://www.svd.se/dynamiskt/inrikes/did_14733730.asp Translation of some passages: "The number of thefts and burglary has been halfed since the city was darkened this autumn  because of the well-known dispute with Ekfors Kraft [local energy company]." "- We thought it would be the opposite, says Sören Mukkavaara, police constaple in Övertorneå.""There is no reliable scientific evidence that outdoor lighting deters crime more than it facilitates crime. There is good evidence that darkness reduces crime."
How to construct a dodecahedron http://everything2.com/index.pl?node=How%20to%20construct%20a%20dodecahedron built around an (inscribed) cube. (using ASCII art)
How to carve a dodecahedron out of a cube http://everything2.com/index.pl?node=How%20to%20carve%20a%20dodecahedron%20out%20of%20a%20cube
The white lotus is a symbol of purity, yet it grows in swamps ... The secret ... was discovered by a German botanist, Dr. Wilhelm Barthlott at the University of Bonn, who spent 20 years studying the microscopic architecture of thousands of plant surfaces with a scanning electron microscope. Dr. Barthlott noticed that the leaves that needed the least amount of cleaning before they were scanned had the roughest surfaces.
And the cleanest leaf of all -- the white lotus -- turned out to have tiny points on it, like a bed of nails, Dr. Barthlott found. When a speck of dust or dirt falls on the leaf, it teeters precariously on those points. When a drop of water rolls across the tiny points, it picks up the poorly attached dirt and carries it away.
The lotus, in other words, has a self- cleaning leaf.
The lotus effect, as it is called, has been applied to a house paint made in Germany called Lotusan. The paint, on the market in Europe and Asia, is guaranteed to stay clean for five years without detergents or sandblasting. Now the lotus effect is being developed for other products, including roof shingles and auto paint.
The lotus effect is an example of biomimicry, an engineering approach that has been gaining momentum in recent years as manufacturers look to nature to solve some engineering problems. By looking at the way plants and animals handle similar kinds of problems, the engineers hope to make products that are less polluting, use fewer materials and even cut costs.
"Businesses should work like a living system," said Janine M. Benyus, a science writer who wrote "Biomimicry," published in 1997, and is now a consultant on the subject. "They should find a way to create conditions conducive to life, not toxic to life."
... tries to mimic abalone shells, which are among the hardest, most durable materials in nature. The shells are made up of alternating layers of hard and soft material. When a crack occurs in a hard layer, it is absorbed by the soft layer and does not spread.
We are taught to value simplicity and beauty. That's nice. I like circles too.
However, complexity is not always the enemy. What's important is not simplicity or complexity, but how you bridge the two.
You need a certain amount of complexity to do any particular job.
Clifford Pickover suggests `` In 105 AD, Ts'ai Lun reported the invention of paper to the Chinese Emperor. Ts'ai Lun was an official to the Chinese Imperial court, and I consider his early form of paper to be humanity's most important invention''
John Henry Holland (who ``discovered'' genetic algorithms): ``board games offer ... an entry into the world of long horizons and rigorous thought -- both in short supply''
Tor Nørretranders: ``the mirror ... widespread production and use of mirrors that came about in the Renaissance ... the modern version of self-consciousness: Viewing oneself through the eyes of others, rather than just from the inside or through the eyes of God. ... Hence, consciousness as we know it is an effect of an advanced mental task: To acknowledge the person experienced out there in the mirror as the same as the one being simultaneously experienced from within. To know that the person out there in the mirror is controlled by me in here. The invention of the mirror is closely related to the problem of free will and to the invention of the modern human ego ... Many malaises of modern life stems from the fact that one tends to consider the mirror-image of oneself as more real than the view from within. ''
James Bailey: ``the bit ...the bit which, used in parallel profusion, can embody living realities far beyond the expressive power of static text. Images and music are just the beginning of it.''
Howard Rheingold: ``There is no such thing as the single most important invention of the last two thousand years. The evolution of technology doesn't work like that. It's a web of ideas, not a zero-sum game. Knowing how to turn knowledge into power is the most powerful form of knowledge. The mindsets, mindtools, and institutions that make massive technological progress possible are all part of an invisible cultural system -- it is learned, not inherent, it was invented, not evolved, it hypnotizes you to see the world in a certain way. ... We have a lot of the knowledge that turns knowledge into power. We need more of the wisdom that knows what we ought to do with the power of invention. ''
and many other interesting tidbits.
The early promise of smart structures -- equipping spacecraft, aircraft, automobiles and ships with networks of sensors and actuators that allow them to respond actively to changing environmental forces, an approach predicted to revolutionize their design, construction and performance -- has never materialized.
That is because ... when such networks grew beyond a modest size of about 100 nodes, they became too complex for central computers to handle. In addition, the weight, power consumption and cost quickly became prohibitive. In other words, they could not be scaled up to large sizes.
... recent advances ... appear to be overcoming these limitations, reported Kenneth Frampton, assistant professor of mechanical engineering at Vanderbilt, ...
Frampton, ... and his colleagues have incorporated these advances ... to design a smart vibration-reduction system for a 15-foot-long rocket payload faring. Currently, the high noise and vibration levels inside rockets ... significantly increase the cost of manufacturing satellites and other equipment boosted into space. So a system that reduces these levels by even a small amount would cut payload development costs substantially.
... a detailed computer simulation of the system ... showed it should provide a degree of vibration-reduction comparable to that of a centrally controlled smart system.
"... the embedded system is scalable," says Frampton. "That means we should be able to build it as big as we need to and it should continue to function."
In the older approach, all the sensors and actuators are connected to a central computer. It receives information from all the sensors, processes it and then sends instructions to all the actuators on how they should respond. As the size of the structure and the number of sensors and actuators increase, the amount of wiring required increases dramatically. Difference in arrival times of information from the nearest and farthest sensors also increases, as does the time it takes the farthest sensors to receive their orders. The bigger the system, the greater these and other problems become.
In an embedded system, on the other hand, each node contains a ... microprocessor with a relatively simple program and modest amount of memory that allows it to directly control the sensors and actuators wired to its node. The microprocessor also communicates with its nearest neighbors so they can work together. ... Although each processor has considerably less capability than that of a central computer, it has far less information to handle, and its workload does not increase as the system gets bigger.
"Embedded systems are also far more 'fault tolerant' than centrally controlled systems," Frampton points out. If the central processor breaks down, the entire system shuts down. But a decentralized system will continue to work even when several microprocessors fail, although ... with ... diminished capability.
The second step in Frampton's project is to put a 100-node system into an actual rocket faring comparable to the simulated system. Then he will test how well in it performs ... This information will allow the engineers to get better estimates not only of the system's performance but also its weight and cost.
Collaborators on the project include Research Assistant Professor Akos Ledeczi, Associate Professor Gabor Karsai and Associate Professor Gautam Biswas from the Vanderbilt Department of Electrical Engineering and Computer Science.
Kenneth D. Frampton http://people.vanderbilt.edu/~ken.frampton/ [FIXME: read his publications]
http://bugzilla.mozilla.org/show_bug.cgi?id=100309#c22 one implementation: http://members.aol.com/wrld0rigin/povwrldjpg.htm
Brian "NeTDeMoN" Bober 2001-11-25 23:10
... Is there any way we can get a good idea of the concentration of Mozilla people in different areas? I thought possibly a site could go up called people.mozilla.org that Mozilla people can add themselves to. Then on a map of the world the concentration of Mozilla people could be colored in. They can click their location on the map if its not one of the choices.
Boeing Phantom Works is involved in some interesting Research and Development Projects: the Blended Wing Body (BWB) aircraft, the Canard Rotorwing (CRW) aircraft, several UAVs (unmanned aerial vehicle), and several spacecraft.
Boeing Phantom Works is developing some interesting Advanced Technologies & Processes: Open Systems Architectures (perhaps this is related to GNU radio todo.html#GNU_radio ), Phased Array Antennas, ``automated fiber placement. Because individual composite fibers wrap more smoothly around complex shapes than composite sheets do, fiber placement can produce large, complex-shaped composite structures - ... much better, faster and about 40 percent cheaper than traditional approaches.'', Stitched RFI: ``stitched resin film infusion... involves sewing together layers of dry composite woven fabric and then infusing it with resin under heat and pressure. Compared with conventional pre-preg composite processes, stitched/RFI can produce more near net-shaped structures that resist delamination'', Friction Stir Joining.
(Is this a completely different division of Boeing ?) The XSS Micro-satellite series http://boeing.com/defense-space/space/xss/index.htm ``micro-satellites ... are fully equipped with on-board avionics, propulsion and high-resolution cameras allowing a highly maneuverable micro-satellite to perform close proximity inspection. ... micro-satellites will perform maintenance and repair activities that extend the life and performance of orbital assets sooner, and at less cost, than replacement from the ground.''
(Is this a completely different division of Boeing ?) INTERNATIONAL SPACE STATION http://boeing.com/defense-space/space/spacestation/sitemap.html SPACE SHUTTLE http://boeing.com/defense-space/space/hsfe_shuttle/sitemap.html (Is this a completely different division of Boeing ?) Boeing Satellite Systems http://boeing.com/defense-space/space/bss/sitemap.html ... the Boeing Digital Signal Processing section http://boeing.com/defense-space/space/bss/dsp/ is building very large DSP systems (2000 complex DSP ASICs per payload) and phased-array antennas. ...
"silicon... mesogyroscope ... gyroscope-on-a-chip ... The sturdy devices are smaller than a dime for the microgyro to slightly larger than quarter size for the mesogyro. ... no rotating parts to wear out and work by measuring vibrations." -- http://boeing.com/defense-space/space/bss/factsheets/gyro/gyro.html [FIXME: vlsi]
``Too much of a good thing? The hidden perils of wabi-sabi'' article by Karen Olson [FIXME: broken link http://www.utne.com/ ] ``wabi-sabi, the art of imperfect beauty'' ... warns us about ``faux wabi-sabi, that new-that-just-looks-old trend'' and warns about using it as an excuse for slovenliness or incompetence.
``Wabi-Sabi: The Art Of Imperfection'' article by Robyn Griggs Lawrence [FIXME: broken link http://www.utne.com/ ] ``wabi-sabi. Emerging in the 15th century as a reaction to the prevailing aesthetic of lavishness, ornamentation, and rich materials, wabi-sabi is the art of finding beauty in imperfection and profundity in earthiness, of revering authenticity above all. In Japan, the concept is now so deeply ingrained that it's difficult to explain to Westerners; no direct translation exists.
Broadly, wabi-sabi is everything that today's sleek, mass-produced, technology-saturated culture isn't.''
``Exquisite decay: Wabi-sabi restores a measure of sanity to modern living.'' article by Leonard Koren [FIXME: http://www.utne.com/ ]
If you draw your coordinate axes so that the origin is at the parabola's vertex and the y-axis points in the direction toward which the parabola opens, then its equation will take the form y = a*x^2 for some constant a, and the focus is the point (0,1/(4*a^2)). Similarly for a paraboloid: if the paraboloid opens in the direction of the z-axis, it will have an equation of the form z = a*(x^2 + y^2), and the focus is at the point (0,0,1/(4*a^2)).
However, these formulas are not much use in finding the focus of a particular dish you have lying around ... you'd be better off finding the focus directly by experimentation (e.g., shine several parallel light beams at the dish, each parallel to the main axis of the dish, and observe where they converge). You'd likely get more accurate results that way than trying to determine the equation of the dish by measurements.
How To Build A Parabolic Dish http://www.math.toronto.edu/mathnet/questionCorner/parabolicdish.html mentions the ``liquid method'' [FIXME: list the other methods] "The Conics" http://ccins.camosun.bc.ca/~jbritton/jbfunpatt.htm#TOPIC7 points to http://www15.addr.com/~dscher/foldedrect.html which discusses how to draw a parabola by folding the paper (so the edge of the paper touches the focus ???)
"Notes on Laying Out a Parabola" http://www.gizmology.net/parabola.htm shows how to draw a parabola with a pin, a T-square, and some string.
Omega uses the plastic/acrylic crystal because it is shatterproof. While sapphire is scratchproof (virtually), it isn't safe at very intense pressure levels. An astronaute would have a very HUGE problem if his sapphire crystal shattered at 0 G. ...
Besides, a Hesalite (plastic/acrylic) crystal can very easily be polished out, but if you ever scratch/chip your sapphire crystal, you will have to replace it or live with it as Sapphire is so hard it's exceedingly difficult to polish out any scratches... http://www.timezone.com/article.aspx?id=omegafaq&articleId=omegafaq631683533963409015#Why_doesn't_the_Speedmaster_have_sapphire_crystal?
The purpose of the avant-garde remains at least in part the opposition of the culture of mass production -- a culture which by its nature must be predigested to the lowest common denominator for mass consumption. The avant-garde must also provide a counterpoint to the elitist cult of the Classical and the worship of ancient forms inherent in the Academic world. ...
So in the same way that Modern art tried to cast down the idols of traditional art, contemporary watch design seeks to go beyond the twilight of conventional ideals to a new day. To push forward evolution rather than dwell comfortably in stagnation. "To strive, to seek, to find, and not to yield."
``...The game was invented in 1985 by mathematician Alexey Pajitnov, then a computer engineer at the Academy of Science's Computer Center in Moscow. ...
In this context, the computer scientists discovered that maximizing the number of rows cleared while playing the given sequence of pieces belongs to a category of problems described as NP-complete. An NP problem is one for which it is relatively easy to check whether a given answer is correct, but may require an impossibly long time to solve by any direct procedure. Interestingly, the computer game Minesweeper also belongs to the NP-complete category.''
Has the equations for converting between latitude, longitude <==> x,y,z, and has some good equations for converting between that and the (X,Y) on flat paper (of course these equations are different for the different projections).
Also has good advice for drawing these nets using common spreadsheet functions. (the author used Excel and Windows Paint)
[FIXME: this claims that ``Equal-Area Projection: diameter of primitive circle equals that of the projected sphere times the square root of two.''. sketch a simple proof.]
Let's call a map ideal if does two things.
- It maps great circles to straight lines.
- It preserves angles.
Does an ideal map exist? [no]
Are there maps that have one of the propeties? [yes] ...
``Like stockpiling atomic bombs, this approach works best if you're the only one doing it.'' -- Philip Greenspun book.html#Philip_Greenspun http://philip.greenspun.com/wtr/dead-trees/story.html
Keeping things simple is the key to consistent organization. Simplicity encourages clarity. And clarity, or clear thinking, allows us to keep things manageable and easy to duplicated in other areas of our lives.-- _Let me look in your drawers: Simple solutions for the organizationally Challenged_ book by Melinda T. Mitchell 2001 http://www.GreatSolutionsPress.com/ [simplicity]
In 1800, the United States boasted about 10 engineers, a situation so dire that six years earlier, George Washington had established an Engineering Corps at West Point to train future military engineers. By 1816, the number of civil engineers had nearly tripled, to 27. The Erie Canal was engineered by land surveyors.
Benjamin Wright, the canal's Chief Engineer ...
The most immediate effect of the canal was, as Hawley had predicted, to slash the cost of shipping to and from the Great Lakes by an order of magnitude. Disruptive technology, indeed!
To grossly oversimplify events, the railroads killed the canal with faster and cheaper cargo transportation, whereupon trucks and automobiles killed the trains with faster and more convenient access. In each case, designers could not foresee the next disruptive technology or its effect on their planned system.
... the evidence that we're approaching a discontinuity seems clear. ...
Vernor Vinge discussed the coming technological discontinuity at length in his books, most notably Across Realtime (now out of print), and in the article found at http://www.ugcs.caltech.edu/~phoenix/vinge/vinge-sing.html .
Perhaps the cost of an on-site service call renders the parts cost irrelevant, but one wonders if a better design might eliminate the problem entirely. ...
High-reliability system engineering already includes fault tolerance analysis, operator training requirements, and a myriad of other topics that are completely foreign to the low-end embedded design process. As those low-end systems become more complex, more interconnected, and more essential, we're beginning to see more failures that affect more people in much nastier ways. Seemingly simple systems must begin to shoulder the cost of doing thorough designs and careful implementations ...
[FIXME: move to generalist / specialist]
So what is the objective here? ...
... the obvious choices are not the only ones ...
Industry is requiring increasing specialization of its workers, due to the overwhelming amount of expert knowledge associated with every technology. This yields positive results but at a severe cost -- specialists inevitably lose sight of the big picture. There is thus a growing market for people who travel continuously among specialists, cross- fertilizing at every stop. No trade journal or annual conference can accomplish as much as a renegade cadre of curious technoid generalists, ...
BEHEMOTH: the Megacycle is Bornarticle by Steve Roberts http://www.microship.com/bike/behemoth/beginnings.html has some interesting product specifications; perhaps some would be interesting features to add to other products:
DAV: the ability to type (articles and email) while pedaling is interesting. I still haven't seen exactly how his text entry works, but if I had to do it from scratch, my first inclination is to take the keybowl serialportdocs.html#keybowl idea and miniaturize it so I could hold onto my handlebars firmly with my fingers, and push the 2 domes with my thumbs. Or perhaps let the grips twist slightly ( with a stop in both directions and a spring-return to center) plus something else. Perhaps there's a better way. [keyboard]
... Malcolm McLean ... He died in relative obscurity, though he was arguably one of the greatest contributors to the growth of the world economy in the 20th century. ... Baltimore Sun stated that "he ranks next to Robert Fulton as the greatest revolutionary in the history of maritime trade." Forbes Magazine called him "one of the few men who changed the world."
Malcolm McLean invented the shipping container in the 1930s in New Jersey, while sitting at a dock waiting all day for cargo he had carried there in his truck to be reloaded onto a ship. He figured out a better way to pack goods and transport them by sea -- which was to secure them in large steel boxes that could be easily loaded onto ships. And in so doing he came up with an idea that changed the face of global trade.
... Today, approximately 90% of cargo moves by container, ...
... His development and successful commercialization of the concept led to a number of US patents being issued. These had the potential to effectively bar others from enjoying the benefits of containerization. One in particular, USA. Patent Number 3 042 227, concerned the design of the corner fittings. It is the standardization of container sizes and these fittings by ISO that has been so essential to the free intermodal interchange of containers and the ensuing dominance of the freight container in international commerce. This standardization effort was made possible by Malcolm McLean's release of the patent. He provided to ISO a royalty free license, allowing use of his patented designs in the creation of an international standard. This standard, ISO 1161, (Corner Fittings), is the very basis for all of ISO's very successful work on freight containers and the commercial success of the container concept that Commissioner Bonner so aptly described in his speech.
It is with great gratitude ... that the members of ISO/TC 104, (Freight containers) mourn the loss of this extraordinary man.
Dispersing the Ducksarticle by Wendy Harris, BS http://www.bjup.com/resources/articles/balance/1906b.html While thinking about the
big, important issuesis good, reserve a little time to think about how to overcome small annoying problems. [general design rule ?]
A metal device with four projecting spikes so arranged that when three of the spikes are on the ground, the fourth points upward, used as a hazard to pneumatic tires or to the hooves of horses.
The Programmer's Taleby Dave Dyer http://www.andromeda.com/people/ddyer/tale.html
one very simple, ironclad rule; If you can plug in in, it's ok to plug it in. There is no way you can plug an ethernet cable into a console socket, or plug a console into a power source, or even plug one kind of power cable into another kind of power outlet. They're all shape coded so it's physically impossible to plug something in to someplace it doesn't belong. It may not be the right place, but it's the right kind of place.
Boom! Sparks! Smoke!
most populated areas in the US have small settlements every 6 miles or so, in part because of the way the land was divided up when opened for colonization ... and in part because you needed a market for local farmers that they could get to and back in a day with a wagon full of goods.also lists several cities that were started after 1900
The one thing that is close to a true universal for all these is the presence of a steady supply of fresh water. Nothing is as important. Available farmland is second, although it is not a necessitymentions that Los Angeles was originally known as
El Pueblo de Nuestra Senora La Reina de Los Angeles de Porciuncula... building new cities (vs. just growing pre-existing cities) [#city] [urban planning]
Cyburbia -- the urban planning portal http://www.cyburbia.org/forums
http://fusionanomaly.net/cropcircles.html more crop circles
It takes patience and ingenuity to pack these small kits with as much as possible. ... The secret is not to be afraid to start all over again when it all doesn't quite fit. Sometimes it just won't, but often it just takes another approach to how you pack it in.
... when you have a tightly packed kit ... it isn't going back together once you open it in the field. [Some] of what's inside will need to be able to be stored in your pockets once the kit is opened. Some include a small plastic or cloth bag for holding this stuff afterwards.
This ugly little machine, this unholy steel trilobyte of Victorian levers and gears, worked just as well now as it had 32 years ago, the day it was made! Such simplicity! Such integrity!http://www.e-sheep.com/almostguy/87.html
http://www.trampoline.com/ "Super-Fun Trampolines will hold up to 450 lbs"
[eye candy] http://www.active-ingredient.co.uk/ http://www.kidsource.com/ "education and healthcare information"
AIR COMPRESSOR: A machine that takes energy produced in a coal-burning power plant 200 miles away and transforms it into compressed air that travels by hose to a Chicago Pneumatic impact wrench that grips rusty suspension bolts last tightened 40 years ago by someone in Abingdon, Oxfordshire, and rounds them off.
... [too often people think] The most obvious answer must be the correct answer.
... there is no place like physics to find out that the obvious answer is the wrong answer. In General Relativity and in Quantum Mechanics there are physical effects which can be measured and verified in the laboratory, but which have very non-intuitive origins. ...
... estimation procedures and simplifications that can lead to a sanity check pre-solution. ...
... Four hundred thousand pounds of aluminum traveling at 600 knots relies on a complex web of wiring, electronics, mechanics, and plumbing to keep the passengers safe. It's astonishing a modern plane works at all, yet air travel is the safest form of transportation ever invented. The reason is the feedback loop that turns accidents into learning experiences.
Contrast air travel with the carnage on our roads. ...
the slide rule: "William Oughtred used Napier's logarithms as the basis for the slide rule (Oughtred invented both the standard rectilinear slide rule and the less commonly used circular slide rule)." http://www.maxmon.com/1600ad.htm
The decimal point: "perfected" by John Napier (1550-1617).
The binary system: invented by John Napier (1550-1617) (DAV: although gray code is often superior ...)
Mercedes Benz not only gave their airbag technology away, they actually paid to teach other companies how to engineer airbag systems for their cars -- their competitors!http://www.kuro5hin.org/comments/2003/7/19/164918/809?pid=188#215
... somehow related to steampunk http://groups.yahoo.com/search?query=steampunk ?
... You must exercise ruthless care to keep things to a minimum, or else you wind up with forts or villages that take up so much area that the troops don't have enough room to maneuver on the rest of the table.
When writing rules for special situations, remember -- unless there is great benefit to doing it otherwise:
- Simpler is better than complicated.
- Faster is better than slower.
- Doing it the same way as something else is better than doing it differently from anything else.
- Heavily favoring the defender is more realistic, but leads to a longer, duller game than mildly favoring the defender.
Small is Beautiful Contrary to what your significant other might tell you, size matters -- especially in tabletop gaming. Specifically: small is beautiful. Because table space is always so limited, everything used in a game must be as small as it can be and still do its job.
Crazy Aaron's Thinking Putty! In adult-sized handfuls and amazing colorshttp://puttyworld.com/
-- Jennifer April 07, 2003 http://www1.alphasmart.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=22;t=000295;p=1#000010 [agument for simple, specialized tools rather than all-in-one combo tools]
..it is impossible to have it be a perfect system. This is one thing that the Alphasmart has over the Dana -- it does one thing, and one thing only. Lots fewer places for bugs to creep in to cause crashes.
But nothing is going to be foolproof. Even pen and paper has its problems (lose the notebook, spill your mochachino, etc). MS Word can corrupt a file on save (don't use Fast Saves), and if the computer crashes during an auto-save, you may lose more than what you were working on in that last writing session.
But there is only so much that can be protected from the unpredictable. So save often, and in different formats, and you'll be as safe as you can be.
The present results came from a student project on the coefficient of restitution between croquet balls and mallets, made in order to establish the variations which exist for typical equipment. The project included some measurements of the area and duration of contact???
I've seen figures suggesting that in an urban driving cycle the energy consumption distribution is 18% to aerodynamic losses, 22% to rolling resistance, and 60% to inertia.[FIXME: need a reference; need highway driving numbers]
... one model of accident investigation known as SHELL - "Software, Hardware, Environment, Livewire, Livewire" - livewire being jargon for humans.
And Dr O'Boyle added: "It's quite easy to blame the pilot but that is rarely the full story.
"Human action may just be the final trigger in a complicated series of inter-locking factors.
"Accidents are never so simple as they seem at first sight."
"It's disappointing to see manufacturers releasing phones that they know are hobbled by tradeoffs. It's as if they deliberately don't want to make the perfect cell phone," says industry outsider Eric Harris.
A chronology of some past missions to Mars. Of 34 unmanned American, Soviet and Russian missions to the planet since 1960, two-thirds have ended in failure.
Celtic Knots http://pims.math.ca/knotplot/celtic/
the Celtic Knot Font http://clanbadge.com/knots.htm
Knots on the Web http://www.earlham.edu/~peters/knotlink.htm
DAV: I'm also interested in celtic/arabic lattice drawings/"knots".
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