Built on Facts

Archives for June, 2010

The laser pointer, much beloved of PowerPoint lecturers, cat owners, amateur scientists, and middle school boys at movie theaters, is actually a pretty amazing device. There’s quite a bit you can do with a relatively cheap laser, and they’re just plain fun. They’re also relatively safe. The red pointers are usually Class 2 and the…

I’m not normally much of a soccer fan, but the World Cup doesn’t happen every day and it’s pretty interesting to see all the excitement and high level of play. I personally think the rules need a little tweaking to reduce the tendency toward 0-0 and 1-1 ties, but I suppose the sport couldn’t have…

On a web forum I frequent, a person asked if it would be possible to extract energy from the Earth’s magnetic field. He was told no – static magnetic fields can’t transfer energy. For all practical purposes this is true, but in fact we also know that the earth’s magnetic field isn’t static. It changes…

Laser Safety and the Vuvuzela

As you might expect for a guy who does experimental optical physics, I get to spend a tremendous amount of time in labs with some fairly snazzy lasers. Most of them are fairly specialized pieces of equipment that aren’t really designed simply to dump huge amounts of power in industrial applications. As far as danger…

Sunday Function

A while back I mentioned the St. Petersburg paradox. It’s a hypothetical gambling scenario where you win money based on the outcome of a coin toss. If you get your first tails on the first throw, you get $1. If you get one head before your first tails, you get $2 dollars. If you get…

Yelling at your coffee

This is a poster in a hallway here in the Texas A&M physics building: Sort of an odd question, but an interesting one. Sound waves carry energy, and if that energy we being absorbed by your coffee because you were yelling at it, how long would you have to do so before it was piping…

Sunday Function

Back in 2003, I was a college freshman sitting in my first college math class – Honors Calculus I. On what was probably the second or third day of class, the professor gave us a surprise quiz. It was something like: “Give the formal statement of the principle of induction”. It was my first graded…

Zero-point free lunches

Grab a particle and put it in a box. According to elementary quantum mechanics, that particle isn’t described by the classical model in which it can have any value of energy as it bounces around. Instead, the possible energy levels of that particle are described by a discrete set. When you measure the energy of…