Mark Chu-Carroll is a Computer Scientist working as a researcher in a corporate lab. My professional interests run towards how to build programming languages and tools that allow groups of people to work together to build large software systems.
goodmath
Posts by this author
January 1, 2007
So, we've built up some pretty nifty binary trees - we can use the binary tree both as the
basis of an implementation of a set, or as an implementation of a dictionary. But our
implementation has had one major problem: it's got absolutely no way to maintain balance. What
that means is that…
December 30, 2006
By way of the astronomy picture of the day, I encountered a really fantastic site about the analemma.
The analemma is the apparent path that the sun takes in the sky during the year. If you record the
precise position of the sun at the same time every day, instead of being in exactly the same…
December 29, 2006
I've mostly been taking it easy this week, since readership is way down during the holidays, and I'm stuck at home with my kids, who don't generally give me a lot of time for sitting
and reading math books. But I think I've finally got time to get back to the stuff
I originally messed up about…
December 29, 2006
Friday Not-So-Random Five
I decided in honor of the new year, I'd do something a bit different this week. Instead of
doing a random shuffle on my IPod, I separated out my favorites of the modern classical pieces that I discovered this year. Some of these are brand new recordings just released this…
December 26, 2006
Like my friend and blogfather [Orac][orac], I'm a huge fan of Doctor Who, and I've been
greatly enjoying its renewed life in the new series on BBC. In fact, the current Doctor, played by David Tennant, has become my favorite of all of the Doctors - better than the
usual fan favorite of Tom Baker,…
December 26, 2006
Being a Nice Jewish BoyTM, Christmas is one of the most boring days of the
entire year. So yesterday, I was sitting with my laptop, looking for something interesting to read. I try to regularly read the [Panda's Thumb][pt], but sometimes when I don't have time, I just drop a bookmark in my "to read…
December 22, 2006
1. **Lunasa, "Feabhra"**: My favorite traditional Irish band. These guys are *really* traditional
instrumental Irish - Uillean pipes, flute, guitar, bodhran, and bass. The pipe player is
without doubt one of the best, if not *the* best in the world. I thought that I hated all kinds
of…
December 22, 2006
Today, I'm going to show you a very simple, very goofy little language called "SCEQL", which standards for "slow and clean esoteric queue language". It's based on nothing but a circular queue
of numbers with nothing but 8 commands. It's not one of the more exciting languages, but it can
be a lot of…
December 21, 2006
The topology posts have been extremely abstract lately, and from some of the questions
I've received, I think it's a good idea to take a moment and step back, to recall just
what we're talking about. In particular, I keep saying "a topological space is just a set
with some structure" in one form or…
December 20, 2006
In Haskell, there are no looping constructs. Instead, there are two alternatives: there are list iteration constructs (like foldl which we've seen before), and tail recursion. Let me say, up front, that in Haskell if you find yourself writing any iteration code on a list or tree-like structure,…
December 19, 2006
Over the weekend, in an attempt to cheer me up, a kind and generous reader sent me a link
[to a *really* wonderful site of crackpot science][adams]. It's a crackpot theory about how physics has it all wrong. You see, there is no such thing as gravity - it's all just pressure. And the earth (and all…
December 18, 2006
This week's "Ask a ScienceBlogger" is an interesting one, but *very* tricky to answer.
The question was proposed by fellow SBer [Dave Munger:][munger] **"What's a time in your
career when you were criticized extremely harshly by someone you respect? Did it help you or
set your career back?"**
[…
December 15, 2006
GM/BM has been pretty slow overall this week, both in new posts and in my responses to comments on previous posts. It was both bigtime deadline week on my project at work; and a very bad week for family health issues.
My dad, who I've mentioned on this blog a lot of times because of the fact that…
December 14, 2006
Following in the footsteps of [orac](http://scienceblogs.com/insolence) and [PZ](http://www.scienceblogs.com/pharyngula) among others of my fellow SBers, I've taken the survey to find out which historical lunatic I am. And I must say, I'm pleased with the results!
Which Historical Lunatic Are You?…
December 13, 2006
Don't forgot: GM/BM is a finalist in the weblog competition for best science blog. I've got no chance of winning, but there's a slim chance that I could make third or fourth. You can vote once per day.
December 13, 2006
Continuing from where we left off yesterday...
Yesterday, I managed to describe what a *presheaf* was. Today, I'm going to continue on that line, and get to what a full sheaf is.
A sheaf is a presheaf with two additional properties. The more interesting of those two properties is something called…
December 12, 2006
Suppose we've got a topological space. So far, in our discussion of topology, we've
tended to focus either very narrowly on local properties of **T** (as in manifolds, where locally, the space appears euclidean), or on global properties of **T**. We haven't done much to *connect* those two views.…
December 12, 2006
While there's nothing mathematical about this bit of silly woo, I couldn't resist mocking it. There's a Japanese inventor who claims to have created a device that instantly ages wine through a magical homeopathic-sounding process of magically restructuring water molecules.
For why I can't resist…
December 11, 2006
In my last topology post, I started talking about the fundamental group of a topological space. What makes the fundamental group interesting is that it tells you interesting things about the structure
of the space in terms of paths that circle around and end where they started. For example, if you'…
December 9, 2006
This was posted on slashdot, and forwarded to me by several readers. It's worth listening to the first few minutes to get an idea of just how pathetically inummerate many people are. It might also help convince you to stay the hell away from *any* service provided by Verizon; my experience with…
December 9, 2006
So, Goodmath/Badmath was nominated for a weblog award for the best science blog. I was actually planning on ignoring it for two reasons. First, Pharyngula was nominated in the same category, and there is absolutely no way that I can *hope* to complete with PZ. And second, the Weblogs are kind of…
December 8, 2006
Our pathological language this week is [Underload][underload]. Underload is, in some ways, similar to Muriel, only it's a much more sensible language. In fact, there are actually serious
practical languages called *concatenative languages* based on the same idea as Underload: [Joy][joy] and [Factor…
December 7, 2006
Tons of folks have been writing to me this morning about [the BBC story about an idiot math
teacher who claims to have solved the problem of dividing by zero][bbc-story]. This is an absolutely *infuriating* story, which does an excellent job of demonstrating what total innumerate idiots reporters…
December 6, 2006
One thing I've been hearing a lot lately is discussions about Ethanol, and it's been
really pissing me off. Can ethanol be a serious replacement for oil as a source of energy? I don't know. Because *both* sides are using really bad math to make their arguments.
There are two fundamental questions…
December 6, 2006
Last time around, I walked through the implementation of
a very simple binary search tree. The implementation that I showed
was reasonable, if not great, but it had two major limitations. First,
it uses equality testing for the search, so that the implementation is only really suitable for use as…
December 5, 2006
Yesterday at Pharyngula, PZ posted a description of his favorite signaling pathway in developmental biology, the [Notch system.][notch] Notch is
a cellular system for selecting one cell from a collection of essentially indistinguishable cells, so that that one cell can take on some different role…
December 3, 2006
For this post, I'm doing a bit of an experiment. Haskell includes a "literate" syntax mode. In literate mode, and text that doesn't start with a ">" sign is considered a comment. So this entire post can be copied and used as a source file; just save it with a name ending in `".lhs"`. If this…
December 1, 2006
Haskell is a strongly typed language. In fact, the type system in Haskell is both stricter and more
expressive than any type system I've seen for any non-functional language. The moment we get beyond
writing trivial integer-based functions, the type system inevitably becomes visible, so we need to…
December 1, 2006
I'm sure that in the friday pathological programming languages, I have a fondness for languages
that make your code beautiful: languages like [SNUSP][snusp], [Befunge][befunge], [Piet][piet], and such. Those languages all you two-dimensional layouts for their programs.
[snusp]: http://scienceblogs…
November 28, 2006
Fellow [SBer Tara from Aetiology][tara] pointed me at [this bit of inanity][loonytune], which I can't resist mocking:
[tara]: http://www.scienceblogs.com/aetiology
[loonytune]: http://www.wdcmedia.com/newsArticle.php?ID=2306
>The mystery of the human genome has come into clearer focus as…