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Solving a math problem of Schrödinger with Arc and Python
I recently received an interesting math problem: how many 12-digit numbers can you make from the digits 1 through 5 if each digit must appear at least once. The problem seemed trivial at first, but it...
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IPv6 web serving with Arc or Python: adventures in IPv6
I've been experimenting with IPv6 on my home network. In part 1, I described how I set up an IPv6 tunnel on Windows 7 and how IPv6 killed my computer. Now, I will describe how I set up a simple (i.e....
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Solving a math problem of Schrödinger (Part II)
What's the better way to solve a math problem? A few lines of code, or a bunch of mathematical thought? I wanted to solve the following math problem: how many 12-digit numbers can you make from the...
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The Endeavour delay: Complexity, the APU, and the Load Control Assembly
The last launch of the Endeavour space shuttle has been delayed 48 hours (update: indefinitely) due to a problem with the APU heater and the Load Control Assembly. I wanted to find out what exactly...
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My Knuth reward check
I attended a very interesting talk "All Questions Answered" by the famous computer science professor Don Knuth in March, where he talked about many things, including his new book. The talk inspired me...
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My 0.015 minutes of fame on CNN
I recently wound up on CNN for a couple seconds doing some Arduino hacking as part of a segment on Google's workshops. Click the image for the full video. If you don't want to watch the whole thing, I...
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The Mathematics of Volleyball
Recently I was at a multi-day volleyball tournament, which gave me plenty of time to ponder the mathematics of the game. At different points in the game, I'd wonder what the odds were of each team...
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Cells are very fast and crowded places
I recently learned that cells are extremely crowded and busy places. I knew there's a lot of activity in cells, but I didn't realize just how much until I was reading Molecular Biology of the Cell. I...
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A new multi-branch algorithm to render rational-exponent Mandelbrot fractals:...
If you came here from Hacker News, thanks for visiting. You might want to check out the Hacker News comment thread too. The Mandelbrot fractal is generated by repeatedly iterating the complex function...
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JavaScript secrets of Bret Victor's homepage
I recently came across the site worrydream.com, which implements an amazing navigation experience through JavaScript and HTML5. The page displays dozens of page icons arranged into angled strips that...
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Apple didn't revolutionize power supplies; new transistors did
a.ref { color: gray;vertical-align: super; text-decoration: none; font-size:60%;margin-left: 2px;} The new biography Steve Jobs contains a remarkable claim about the power supply of the Apple II and...
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Tiny, cheap, and dangerous: Inside a (fake) iPhone charger
a.ref { color: gray;vertical-align: super; text-decoration: none; font-size:60%;margin-left: 2px;} I recently wrote a popular article on the history of computer power supplies, which led to...
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Apple iPhone charger teardown: quality in a tiny expensive package
Disassembling Apple's diminutive inch-cube iPhone charger reveals a technologically advanced flyback switching power supply that goes beyond the typical charger. It simply takes AC input (anything...
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A dozen USB chargers in the lab: Apple is very good, but not quite the best
table.chargers { border-width: 1px; border-spacing: 2px; border-style: outset; border-color: gray; border-collapse: collapse; background-color: white; } table.chargers th.maker { padding-right: 5px;...
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Spectral analysis with the Tektronix 5000 oscilloscope
Many oscilloscopes have advanced spectral analysis features that perform Fourier Transforms on measured signals to generate a frequency spectrum. This article provides a tutorial on how to use these...
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How to create a new schematic symbol in the Eagle editor
This tutorial describes how to create a custom schematic symbol in the CadSoft Eagle editor. It assumes that you have some familiarity with Eagle and just want to create a schematic (not a PCB), but...
View ArticleObama on sorting 1M integers: Bubble sort the wrong way to go
Recently StackOverflow and HackerNews discussed the question of how to sort 1 million 8-digit numbers in 1 megabyte of RAM. This reminded me of when I saw Obama in 2007 at Google - Eric Schmidt asked...
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Teardown of the mysterious KMS 4-port USB charger
In this article I tear down a 4-port USB charger of puzzling origin. This charger is a huge step above the $2 counterfeit chargers I examined earlier in design and manufacture, but considerably below...
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JavaScript on the go: Programming from your phone
Have you ever wanted to write a program when the only computer available is your phone? You can use an Android phone to write and run JavaScript programs by using a few simple tricks. While traveling...
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The 6502 overflow flag explained mathematically
table.overflow { border: 1px solid #888; border-collapse: collapse;} table.overflow th { border-bottom: 1px solid #888;} table.overflow th, table.overflow td { padding: 3px 8px;} .overflow-bl...
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