goodmath

Time for our second visit with old friends. This time, we're going to check up on "The Lords Witnesses", the bible code geniuses who made somewhere around a dozen attempts at using their code to nail down a date at which the UN building in NYC would be blown up. These nutters are a spinoff of the…

As many of you know, I'm a big Doctor Who fan. Big enough that I've grabbed all of the episodes of the new series, and its spinoffs, via BitTorrent. (I also buy them on DVD as soon as they become available.) A few folks have asked me what I think of the spinoffs. And I'm sick at home, feeling like…

To be honest, I haven't been following the Carnival of Math much since it's inception; my new job keeps me busy enough that I barely have time to keep the blog going, and so I haven't really looked much at recent editions. In fact, I completely forgot that I was hosting it again until I started…

A few weeks ago, I received an email about a new book, "The Faith Equation", by Marvin Bittinger. Bittinger is an author of math textbooks - including, I think, my first calculus text. The book is supposed to be Bittenger's explanation of how mathematics validates christianity. Needless to say, I…

Today we've got a bit of a treat. I've been holding off on this for a while, because I wanted to do it justice. This isn't the typical wankish crackpottery, but rather a deep and interesting bit of crackpottery. A reader sent me a link to a website of a mathematics professor, N. J. Wildberger, at…

Sorry for the slow posting this week, but work has been a bit intense, and I've also had some family matters to take care of, which have left me with very little blogging time. Hopefully things will be a bit less insane next week. In the meantime, here's a random bunch of weird music I've been…

Colored Petri Nets The big step in Petri nets - the one that really takes them from a theoretical toy to a serious tool used by protocol developers - is the extension to colored Petri nets (CPNs). Calling them "colored" is a bit of a misnomer; the original idea was to assign colors to tokens, and…

Checking In on Old Friends As long-time readers of this blog know, there are a few crackpots who I've written about multiple times. Those nutters have their fans, and people seem to want to hear about what they're up to. So today, I'll give you a brief look at what's going on with the three fan…

Lo Mein is one of the staples of Chinese restaurants in the US. In general, it's not bad, but it's a bit greasy, and a bit bland. This version of it is closer to authentic, and has a really nice kick. The heat comes from a sauce called Sambal. Sambal is the vietnamese name, but Chinese make it…

There's one variant of Petri nets, called counted Petri nets, which I'm fond of for personal reasons. As Petri net variants go, it's a sort of sloppy but simple one, but as I said, I'm fond of it. As a warning, there's a bit of a diatribe beneath the fold, as I explain why I know about this…

I've been getting a lot of requests from people to talk about the recent Excel bug. For those of you who haven't heard about this, in Excel 2007, floating point calculations that should result in a number very, very close to either 65,535 or 65,536 are displaying their result as 100,000. It's only…

Among many of the fascinating things that we computer scientists do with graphs is use them as a visual representation of computing devices. There are many subtle problems that can come up in all sorts of contexts where being able to see what's going on can make a huge difference. Graphs are,…

As pointed out by a commenter, there are some really surprising places where fractal patterns can appear. For example, there was a recent post on the Wolfram mathematica blog by the engineer who writes the unlimited precision integer arithmetic code. Unlimited precision integers are numbers…

The year before our first kid was born, my wife and I went on vacation in Budapest. It was a beautiful city, and the food was wonderful - I particularly loved the chicken paprikash that they seemed to server everywhere. When I got home, I started looking for recipes to reproduce it. This is the…

Via YouTube, I came across this little gem. Who would have thought that you could create a beautiful fugue from a Britney Spears song? Fugues are one of my favorite musical forms. There's something magical (and something mathematical) about the way it sounds when a theme counterpoints itself.…

As of 2/24/2008, Sewell has just responded to this, pretending that he just noticed it. To make discussions easier to follow, I have responded with a new post here, and I would appreciate it if comments could be posted there, to keep it all in one place. My SciBling Mark Hofnagle over at the…

In the course of the series of posts I've been writing on fractals, several people have either emailed or commented, saying something along the lines of "Yeah, that fractal stuff is cool - but what is it good for? Does it do anything other than make pretty pictures?" That's a very good question.…

Yet another example of how graphs can be used as models to solve real problems comes from the world of project management. I tend to cringe at anything that involves management; as a former IBMer, I've dealt with my share of paper-pushing pinheaded project managers. But used well, this…

I don't remember where I found this, but it's really amazing. The 2005 conference on electron/ion microscopy gave awards for the best bizarre or art-like images produced using electron or ion microscopy. The images range from beautiful, like the C60 crystalline lattice to the right, to…

Since the friday pathological programming died out, I've been looking for something else to do for special friday posts. A while back, I posted a bunch of recipes for a mutant meme, and it seemed a lot of people really liked it. So I've decided to do an off-topic friday thing: friday random…

There's a kind of graph which is very commonly used by people like me for analysis applications, called a lattice. A lattice is a graph with special properties that make it extremely useful for representing information in an analysis system. I've mentioned before that you can use a graph G=(V,E…

Both in comments, and via email, I've received numerous requests to take a look at the work of Dembski and Marks, published through Professor Marks's website. The site is called the "Evolutionary Informatics Laboratory". Before getting to the paper, it's worth taking just a moment to understand…

Last time, I showed a way of using a graph to model a particular kind of puzzle via a search graph. Games and puzzles provide a lot of examples of how we can use graphs to model problems. Another example of this is the most basic state-space search that we do in computer science problems. In…

Much to my professional shame, PZ recently pointed out David Plaisted, a Computer Science professor at the University of North Carolina, who has href="http://www.cs.unc.edu/%7Eplaisted/ce/challenge8.html">an anti-evolution screed on his university website. Worse, it's typical creationist…

Via Atrios, I found this article at the American Prospect, which demonstrates an example of a very common and very serious math error that's constantly made in the media: unit errors. If you want to compare two numbers, you need to make sure that they're actually numbers that can be compared. You…

In one of Jeff Shallit's recent posts on the Panda's Thumb, he mentioned that Tom Bethel, aside from being a creationist, was also a relativity denier. In general, relativity denial is a veritable mine of bad math. So I went looking - and found Bethel's anti-relativity site. As I expected, we've…

As I've mentioned before, the real use of graphs is as models. Many real problems can be described using graphs as models - that is, to translate the problem into a graph, solve some problem on the graph, and then translate the result back from the graph to the original problem. This kind of…

If you remember, a while back, I wrote about a British computer scientist named James Anderson, who claimed to have solved the "problem" of "0/0" by creating a new number that he called nullity. The creation of nullity was actually part of a larger project of his - he claims to have designed a…

Naftule's Dream, "Something is There": What do you get when you mix up a traditional Klezmer band with Ornette Coleman, plus just a bit of thrash? Naftule's Dream. Genesis, "Counting out Time": a catchy little tune from Peter Gabriel's opus with Genesis, "The Lamb Lies Down on Broadway": It's…

When you mention fractals, one of the things that immediately comes to mind for most people is fractal landscapes. We've all seen amazing images of mountain ranges, planets, lakes, and things of that sort that were generated by fractals. Seeing a fractal image of a mountain, like the one in this…