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# Blog Profile / Good Math, Bad Math

URL : http://scientopia.org/blogs/goodmath/ Academics / Mathematics 295 1.1 December 12, 2008

## Blog Post Archive

### Basics: What is an OS?

A reader of this blog apparently likes the way I explain things, and wrote to me to ask a question: what is an operating system? And how does a computer know how to load it? I'm going to answer that, but I'm going to do it in a roundabout way. The usual answer is something […]

To me, the thing that makes probability fun is that the results are frequently surprising. We've got very strong instincts about how we expect numbers to work. But when you do anything that involves a lot of computations with big numbers, our intuition goes out the window - nothing works the way we expect it […]

### The Elegance of Uncertainty

I was recently reading yet another botched explanation of Heisenberg's uncertainty principle, and it ticked me off. It wasn't a particularly interesting one, so I'm not going disassemble it in detail. What it did was the usual crackpot quantum dance: Heisenberg said that quantum means observers affect the universe, therefore our thoughts can control the […]

After yesterday's post about the return of vortex math, one of my coworkers tweeted the following at me: @MarkCC You know vortex math is worthless because it's free. But you know this is legit because it costs: http://t.co/WKIeS6azoU — @lahosken (@lahosken) November 14, 2013 Larry's a nice guy, even if he did give me grief […]

### Vortex Math Returns!

Cranks never give up. That's something that I've learned in my time writing this blog. It doesn't matter how stupid an idea is. It doesn't matter how obviously wrong, how profoundly ridiculous. No matter what, cranks will continue to push their ridiculous ideas. One way that this manifests is the comments on old posts never […]

### Basic Data Structures: Hash Tables

I'm in the mood for a couple of basics posts. As long-time readers might know, I love writing about data structures. One of the most important and fundamental structures is a hashtable. In fact, in a lot of modern programming languages have left hashtables behind, for reasons I'll discuss later. But if you want to […]

### A Note to the Trolls Re: Comment Policies

Since yesterday's post, I've been deluged with trolls who want to post comments about their views of sexual harassment. I've been deleting them as they come in, and that has, in turn, led to lots of complaints about how horrible unfair and mean I am. I've been doing this blogging thing for a long time, […]

### It's easy to not harass women

For many of us in the science blogging scene, yesterday was a pretty lousy day. We learned that a guy who many of us had known for a long time, who we'd trusted, who we considered a friend, had been using his job to sexually harass women with sleezy propositions. This led to a lot […]

### Combining Non-Disjoint Probabilities

In my previous post on probability, I talked about how you need to be careful about covering cases. To understand what I mean by that, it's good to see some examples. And we can do that while also introducing an important concept which I haven't discussed yet. I've frequently talked about independence, but equally important […]

### Weekend Recipes: Chicken Wings with Thai Chile Sauce

In my house, chicken wings are kind of a big deal. My wife doen't know how to cook. Her cooking is really limited to two dishes: barbecued chicken wings, and grilled cheese. But her chicken wings are phenomenal. We've been married for 20 years, and I haven't found a wing recipe that had the potential […]

### Correction, Sigma Algebras, and Mass functions

So, I messed up a bit in the previous post. Let me get that out of the way before we move forward! In measure theory, you aren't just working with sets. You're working with something called ?-algebras. It's a very important distinction. The problem is, our intuition of sets doesn't always work. Sets, as defined […]

### Kolmogorov's Axioms of Probability

The way that I've talked about probability so far is mostly informal. That's the way that probability theory was treated for a long time. You defined probability spaces over collections of equal probability sets. You combined probability spaces by combining their events into other kinds of equally probable events. The problem with that should be […]

### Infinite Cantor Crankery

I recently got yet another email from a Cantor crank. Sadly, it's not a particularly interesting letter. It contains an argument that I've seen more times than I can count. But I realized that I don't think I've ever written about this particular boneheaded nonsense! I'm going to paraphrase the argument: the original is written [...]

### Recipe: Sous Vide Braised Pork Belly with Chevre Polenta

I really outdid myself with tonight's dinner. It was a total ad-lib - not recipe written in advance, just randomly trying to make something good. It turned out so good that I need to write down what I did, so that I can make it again! Part 1: the pork 2 1/2 pounds pork belly. [...]

### Independence and Combining probabilities.

As I alluded to in my previous post, simple probability is really a matter of observation, to produce a model. If you roll a six sided die over and over again, you'll see that each face comes up pretty much equally often, and so you model it as 1/6 probability for each face. There's not [...]

### Probability Spaces

Sorry for the slowness of the blog lately. I finally got myself back onto a semi-regular schedule when I posted about the Adria Richards affair, and that really blew up. The amount of vicious, hateful bile that showed up, both in comments (which I moderated) and in my email was truly astonishing. I've written things [...]

### Probability and Interpretations

I'm going to do some writing about discrete probability theory. Probability is an extremely important area of math. We encounter aspects of it every day. It's also a very poorly understood area - it's one that we see abused or just fouled up every day. I'm going to focus on discrete probability theory. What that [...]

### Speed-Crankery

A fun game to play with cranks is: how long does it take for the crank to contradict themselves? When you're looking at a good example of crankery, it's full of errors. But for this game, it's not enough to just find an error. What we want is for them to say something so wrong [...]

### The Gravitational Force of Rubbish

Imagine, for just a moment, that you were one a group of scientists that had proven the most important, the most profound, the most utterly amazing scientific discovery of all time. Where would you publish it? Maybe Nature? Science? Or maybe you'd prefer to go open-access, and go with PLOS ONE? Or more mainstream, and [...]

### What the heck is a DNS amplification DoS attack?

A couple of weeks ago, there was a bunch of news about a major DOS attack on Spamhaus. Spamhaus is an online service that maintains a blacklist of mail servers that are known for propagating spam. I've been getting questions about what a DoS attack is, and more specifically what a "DNS amplification attack" (the [...]

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