Built on Facts

Archives for March, 2009

A Connundrum

Here is a question. It’s a sort of subtle question, but one that can be answered with freshman-level physics. But it’s an excellent test of understanding. I’m not promising that the question itself is not in some sense a “trick” question, but the trick is in how you might think about the physics, not the…

Space Debris

Sometimes I watch Survivorman on the Discovery Channel. It’s a good show – much better than that other one – by virtue of the fact that the survival is real and he doesn’t have a camera crew around to help him out. Sure he has a way to contact rescue should something go wrong, but…

Drift velocity

Driving in my car for five hours today, I had plenty of time to think about velocity. There’s not much you can do about it, speeding doesn’t take much time off the trip but it does add the risk of an expensive ticket. We single classical particles don’t have a lot of options for getting…

Sunday Function

Well, it’s Gabriel, Gabriel playin’! Gabriel, Gabriel sayin’ “Will you be ready to go When I blow my horn?” – Cole Porter, Anything Goes The commenters in last week’s Sunday Function proposed an excellent idea for this week. As we did then, we’ll start simple and work up to it. Graph the curve f(x) =…

Pi day!

Whew! Busy week for me, hence the missing post or two. Traditionally Saturdays on this blog tend to be non-physics fare – either links, commentary on something nonscientific, or whatever. Today I think it will be the celebration of Pi Day! Pi Day: As you know from the SB main page, today is pi day.…

A reader writes in with a question about the physics of Star Trek: When the Enterprise goes into warp speed (which as I take it are multiples of the speed of light, warp 5, 5x the speed of light, etc.) and they show the ship zooming through the cosmos, they always show the stars its…

Conservatism

Conservative forces, that is! Hold a basketball in your hand and move it around. When you move it up, you do work against gravity. You have to put energy into the system to get it to gain height. Relax your arm, and the force of gravity pulls it downward, converting that potential energy into kinetic…

Savings Time?

Imagine the scientists of the world got together and decided they didn’t like the meter as a unit of distance. They were tired of traveling such long distances to conferences and decided that by redefining the new meters as two old meters, suddenly the plane flight was only 1000 kilometers instead of 2000 kilometers. I…

Sunday Function

Let’s start with a pretty simple function. It’s not this week’s official Sunday Function, but we’ll use it to get there. Take the number 1, divide it by x. Pretty easy. Now imagine putting a dot at the point x = 1 on the x axis, and draw a line straight up from there to…

A primer on federal gun law

As ScienceBlogs’ resident firearms enthusiast (I might own more guns than the rest of the SB writers combined – and I don’t own very many), I’ve occasionally written about gun rights and related issues. One of the things I’ve noticed is that a lot of people aren’t very familiar with what gun laws actually are…