Built on Facts

Archives for November, 2009

Sunday Function

Just a quick one today, as I get caught back up from Thanksgiving. We all know and love the very basic quadratic function. Any second-order polynomial will give you a nice little parabola, which of course is ubiquitous in physics. We all know what that looks like. But what if we’re willing to square complex…

What’s a Lagrangian?

Yesterday, as expected, severe underdog Texas A&M lost to #3 ranked Texas. Not as expected, the game was competitive right to the end, with an upset being threatened down to the final minutes. It was a great game to watch, with a final score of 45-35 – the highest total score in the history of…

First of all, happy Thanksgiving everyone! I hope you spend the day happily with the people you care about, and remember to spend a moment or two reflecting on the things for which you’re thankful this year. Now on with the show: Back when I first started writing this blog, I focused mostly on problem…

Light Bulbs, Improved.

A quick and simple way to roughly check the calibration of a spectrometer is to point it at the ceiling. Fluorescent lights put out a particular spectrum, and by comparing the colors the spectrometer senses to the colors you know the light emits, you can see if your spectrometer is accurate to a first approximation.…

Sunday Function

If you look at an incandescent light in a spectroscope, you’ll see a broad and continuous range of light emitted over a large portion of the visible spectrum. This combination of colors looks white to us. At the other extreme, laser light generally consists of just a tiny slice of the frequency spectrum, and so…

Leaked Climate Change Documents

Around ScienceBlogs, people who don’t accept global warming as a real phenomena tend to get called denialists. In the interests of full disclosure, I should admit that I’m not a denialist but rather a global warming defeatist. Doesn’t matter how bad or not CO2 is, ain’t nothin’ gonna stop it. People will not give up…

Seeing Laser Beams

Ok, see counselor Troi firing her phaser? You see this kind of thing all the time on film in scifi. Whether it’s Star Trek, Star Wars, or pretty much anything else, energy beams fired from future weapons are visible. Usually someone will point out that in fact laser beams are not visible in this manner.…

Al Gore and Geothermal

There’s a little bit of buzz burbling around over Al Gore’s scientific goof during a Conan O’Brien interview. Discussing geothermal energy, he said the following: It definitely is, and it’s a relatively new one. People think about geothermal energy — when they think about it at all — in terms of the hot water bubbling…

Sunday Function

We’re doing two functions today. If I’m not mistaken we’ve done each of them separately, but there’s a famous and interesting relationship between the two that’s always interesting to look at. Like very many interesting mathematical facts, it has to do with the prime numbers. As such the first function is the log integral Li(x),…

The Physics of Gerrymandering

Whew! Interesting day around here yesterday, no? There’s more controversial topics out there: abortion, health care, gay marriage, Iraq, and a few others. But not many. It’s good for sparking discussion, but I also know that some large (probably majority!) fraction of you would prefer to hear about physics. Which is good because generally I…