Built on Facts

Archives for January, 2009

Fire Drill!

[I'm foregoing the usual Saturday miscellany for a Very Special Built on Facts. It's important!] Imagine a basketball sitting on the top of a hill. The slope of the hill is pretty gentle, and so you can roll the ball around a bit without the risk of it rolling away. But hit it too hard…

Physics and Relationships

Yesterday I spend a tremendous amount of time in a very snazzy lab shooting lasers through pyridine. Cool stuff, tempered by the fact that pyridine smells like what Dr. Frankenstein’s lab would have smelled like if Dr. Frankenstein used organic chemistry instead of electricity, and also the thing he was trying to bring back to…

What Entropy Is

The Second Law of Thermodynamics probably produces more confusion in the general public than most other physical laws that have percolated themselves into the collective consciousness. Not the least of these are all the seemingly disconnected ways of saying it, which vary in accuracy. Disorder increases. Absolute zero is impossible. Engines can’t turn heat into…

Slowing the earth

Consider the turntable of an old record player. Or equivalently, a CD affixed to a player so that it may spin freely. We’ll pretend there’s no friction, though as always reality will manage to generate some. Now stretch your imagination a bit further and imagine that you shrink yourself down to a height of about…

Wanderlust

In the comments of yesterday’s post about the output of the sun, Carl Brannen brought up a good point: By the way, in comparing your audience to cows and compost heaps is there some sort of message here? It’s been 25 years or so but I recall that there was a certain time of year…

Star Light, Star Bright

The power output of the sun is often talked about in awe-inspiring terms. You’ll be told that it’s like a continuous thermonuclear blast, or that a tiny fraction of the tiny fraction of power that happens to hit the earth would support humanity’s energy needs. It’s all true. The light and heat from a campfire…

Sunday Function

There’s some math here, I’d rate it at Calc 2 difficulty. If you don’t know calculus, that’s fine! The details will be obscure but I think you’ll still appreciate the abstract beauty of the method. Ok, pick a rapidly oscillating function. It doesn’t really matter which, so as an example I’ll make one up. It…

Best Picture

Today I’m going to soapbox about something utterly inconsequential and only tangentially related to science. Apologies all around. It’s the weekend though, so I trust you’ll forgive a bit of a deviation from the usual! The nominations for the Oscars are out, and generally it’s a pretty mundane lot. Take the Best Picture nominees, for…

Improving on SI

In the United States generally and to a much lesser extent in the UK and a few other countries you’ll see some very old-school units of measurements. Miles, yards, pounds, fortnights, pints, gallons, and numerous others. Most of the rest of the world uses metric units, the primary variant of which is called SI units…

Volume and Entropy

Thermodynamics and statistical mechanics hold a bit of an odd place in the heart and mind of a physics student. On one hand it’s one of the few subjects with truly universal applicability. No matter if you work in galaxy clusters, nuclear theory, experimental solid state, or anything else the concepts of those disciplines are…