probability

On Pharyngula, PZ Myers criticizes the stubborn obfuscations of Michael Behe, who refuses to yield his illogical calculations. Behe says (rightly) that a certain mutation necessary for drug resistance in the malaria parasite has about a 1 in 1020 chance of occurring. But the mutation is also detected in 96% of malaria patients who respond well to the drug; it proliferated widely because, by itself, it had no impact on the parasite's fitness. The parasite needed another mutation, occurring at a later date, to develop resistance to the drug. Behe rests his case for divine intervention on the…
As an alternative to biblical creationism, Intelligent Design infers a less obtrusive God to explain life on Earth. This deity doesn't hurl bolts of lightning, unless it's with the express purpose of sparking abiogenesis in the primordial soup. On EvolutionBlog, Jason Rosenhouse dismisses probabilistic arguments against the likelihood of complex organisms, explaining that even the most improbable-seeming outcome of natural selection is more or less inevitable. As a flawed analogy, he imagines flipping a coin 500 times. This will always manifest a sequence of heads and tails that only had a…
A little while back, Jonah Lehrer did a nice blog post about reasoning that used the famous study by Gilovich, Vallone and Tversky, The Hot Hand in Basketball (PDF link) as an example of a case where people don't want to believe scientific results. The researchers found absolutely no statistical evidence of "hot" shooting-- a player who had made his previous couple of shots was, if anything, slightly less likely to make the next one. Lehrer writes: Why, then, do we believe in the hot hand? Confirmation bias is to blame. Once a player makes two shots in a row - an utterly unremarkable event…
Here is part of a picture some of my friends posted from a recent high school reunion. It may be hard to tell, but this is part of a picture of 7 females all wearing black. I just wanted to show you that they were indeed wearing black without giving away anymore details. If you are one of these people and you want your whole picture included, I will be happy to make that change and include your face. Anyway, my first comment was: "Wow, everyone is wearing black. Was this a planned event or was black part of the dress code?" The response was that it was just pure chance that all the women…
This week's big story in physics is this Science paper by a group out of Austria Canada (edited to fix my misreading of the author affiliations), on a triple-slit interference effect. This has drawn both the usual news stories and also some complaining about badly-worded news stories. So, what's the deal? What did they do in this paper? The paper reports on an experiment in which they looked at the interference of light sent through a set of three small slits, and verified that the resulting pattern agrees with the predictions of the Born rule for quantum probabilities. What does Matt Damon…
I am going to tell a story and then calculate the probability of part of it happening. Really, it's just an excuse for me to put this online (since no one got hurt). My parents have this house on a lake, but it is really hilly. There is a dock down there, but it is like a bajillion stairs to get there. Good for exercise, bad for carrying a cooler full of beer (and ice). I don't know where he found about it, but my Dad got these guys from Minnesota to install this tram thingy. Basically it's a little train car with benches that rides down on two rails to the dock below. The thing is…
I'm a little cranky after a day of reviewing grant proposals, so it's possible that I'm overreacting. But commenter Neil B has been banging on about quantum measurement for weeks, including not one, not two, but three lengthy comments in Tuesday's dog post. For that reason, I am declaring this post's comments section to be the Official Neil B. Quantum Measurement Thread. Until such time as I declare the subject open again, this is the only thread in which I want to see comments about quantum measurement. Attempts to bring the subject up in comments to other posts-- even other posts having to…
Dear Mythbusters. I hope you know that I think you are awesome. I know you are not scientists, but rather master robot builders. I respect that. I envy your robot-building abilities. Please forgive me for pointing this out - but even if a tree is 90% air, that does not mean a ball has a 90% probability of passing through it. For those of you who are unaware, in the last episode of MythBusters, they explored the idea that a golf ball should pass through a tree 90% of the time. What if they were to test following alternative myth: *A golf ball has a 90% chance of passing through something…
When mowing the lawn, I like to listen to podcasts. One of my favorites is [Buzz Out Loud](http://bol.cnet.com). This weekend, I was listening to episode 817 and one of the topics of discussion was MySpace and their DRM free music stuff. [Wired](http://blog.wired.com/music/2008/09/myspace-launche.html) had a description of what they were going to do. That is not my point. The point is the claim that you could make an infinite number of playlists. How about I calculate (or estimate) the number of different playlists one could make. First, the idea behind the idea. Calculating the number…
Ambiguity is a constant problem for any embodied cognitive agent with limited resources. Decisions need to be made, and their consequences understood, despite the probabilistic veil of uncertainty enveloping everything from sensory input to action execution. Clearly, there must be mechanisms for dealing with or resolving such ambiguity. A nice sample domain for understanding ambiguity resolution is language, where problems of uncertainty have been long appreciated. The meaning of words in general (not to mention referents like "that" or "he") can be highly ambiguous (see "the gavagai…