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Multiplication
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May 8, 11:43pm
23 reviews
mathematics, number-theory
http://www.hunkinsexperiments.com/pages/multiplication.htm
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This is a cute way to do multiplication. And for all the naysayers, it's actually useful for more than just 6-10, presuming you have fingers enough and/or don't mind a few negative numbers...
The method presented here boils down to this computation:
xy = 10(x' + y') + (5 - x')(5 - y'),
where:
x' = x - 5, and
y' = y - 5.
The person using this method takes the sum of the bottom fingers on either side (x' + y') and multiplies by 10. Then, adds in the product of the top fingers on either side ((5 - x')(5 - y')).
The interesting bit is the multiplication by 10; why 10? Let's do some algebra:
10(x' + y')
10((x - 5) + (y - 5))
10(x + y - 10)
And now let's bring it all back to where we started:
10(x + y - 10) = xy - (x - 10)(y - 10)
10(x + y - 10) = xy - (5 - x')(5 - y')
10(x' + y') + (5 - x')(5 - y') = xy
Bingo! 10 is selected because it is twice 5.
So say you encounter a russian with n fingers, and he wants to multiply x by y. How would he do it? Setting aside all the finger twiddling and counting, he'd simply be doing this computation:
xy = 2n(x' + y') + (n - x')(n - y').
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[www@cb.vu]~
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Apr 20, 12:32pm
69 reviews
web-design, linux
http://cb.vu/
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So at the least, this is a novel approach to web ui. The page is just a lightweight *nix-flavor shell written in javascript. Almost all of the processing is done by the client browser -- the filesystem and most of the commands you can invoke are fake. There are some interesting nooks (like the snake game), but the site is more concept than function.
It'd be pretty cool to play around with this model and come up with a more functional command-line ui for a real website. On the other hand, sullying one's hands in javascript isn't an appealing prospect...
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How to Start a Startup
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Mar 2, 2007 10:52pm
14 reviews
business, tech
http://www.paulgraham.com/start.html
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Some very comprehensive advice on the hows and whys of building a start-up. I've read several of Paul Graham's articles now, and I've enjoyed each of them immensely. They're definitely worth the time you put into reading them.
On a side-note, Paul has the most appropriately-named VC firm ever: Y combinator. (For those not familiar with lambda calculus, the Y-combinator is a fixed-point operator.)
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http://www.quepublishing.com/articles/article.asp?p=370047&rl=1
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Mar 2, 2007 5:36am
1 review
operating-systems, linux-kernel, process-execution
http://www.quepublishing.com/articles/article.asp?p=370047&rl=1
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I woke up this morning curious about how hard it would be to come up with a graphical visualization of process execution under x86 Linux: stack, heap, tlb, registers, and everything. All color-coded and glorious-like.
Anyway, I ended up reading through this article. It gives the 2.6 kernel's perspective on process execution. It's well-written enough that I'm seriously thinking of buying the book.
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Daily Kos: All About NSAs and AT&Big Brother Machine, the Narus 6400
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Apr 10, 2006 5:23am
7 reviews
network-security, technology
http://www.dailykos.com/storyonly/2006/4/8/14724/28476
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Apparently, all our base are belong to the NSA. Not that it was any surprise, but check out this article about the technology they've planted in various west-coast AT&T internet trunks.
The equipment and software are develeoped by the fine folks over at Naurus, whose latest model is capable of semantically parsing (in real time) 10Gbits of raw traffic per second at layer 4, and 2.5Gbits per second at layer 7. The article points out that a single one of these machines could be analyzing all the raw traffic from 10,000 dsl customers with a fine-toothed comb.
DO Y'ALL REALIZE JUST HOW GODDAMN FRIGHTENING THIS IS?
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http://www.tiobe.com/tpci.htm
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Apr 3, 2006 7:54am
12 reviews
http://www.tiobe.com/tpci.htm
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/me sheds great big crocodile tears over C being dethroned by Java
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Hypercomplex Iterations
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Mar 20, 2006 9:03am
2 reviews
complex-systems, mathematics
http://www.evl.uic.edu/hypercomplex/
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Dunno if this beats the Thorsten Fleisch quaternion video in terms of sheer artistic quality, but it's still pretty neat. And colourized. :)
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BBC NEWS | Science/Nature | Furry lobster found in Pacific
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Mar 20, 2006 8:45am
11 reviews
marine-biology
http://news.bbc.co.uk/2/hi/sci/tech/4785482.stm
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Furry lobsters. I want one.
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Mind Hacks
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Mar 19, 2006 2:14pm
62 reviews
cognitive-science
http://www.mindhacks.com/
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this is a fantastic cogsci blog. definitely a good read.
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Last.fm & The Social Music Revolution
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Mar 19, 2006 8:16am
595 reviews
music, social
http://www.last.fm/
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i know it's old knews for most of you folk out there, but y'all should check out this music/social networking plugin. it's not all that great for the stats, but you can find out about a lot of new music real quick! ;)
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