physics 18

I wasn’t entirely sure, but now I’m somewhat convinced: Magnetix magnets can form an infinite chain that won’t break due by its own weight. (This is not true, however, if you introduce the steel bearing balls between them. That structure collapses pretty quickly if you pull it up like a chain.) So, this would be a really nice question for What If, IMHO. What if you made a 1 light-year chain of Magnetix? Well, to begin with, we’d need nearly 40 million trillion pieces. That’d cost at least 10 million trillion dollars based on the current prices at Amazon, and would be about 140,000 times the world’s GDP. I’m sure Randall could take this a lot further. ...

Videos of amazing physics experiments.

I’ve seen many proofs that 1=2. Here’s a classic. The (not-so-subtle) error in the above proof is that we’re cancelling (a-b) on both sides, when (a-b) equals zero. That is, we’re dividing by zero on both sides. That completely invalidates the equality. Another proof uses the fact that the square root of a number can be both positive or negative. ...

How to safely land a plane - by blowing one of its wings off. Strangely, that’s what Superman does in Superman Returns. (see video of Superman saving a plane).

Why spaghetti does not break in half. It usually breaks into three or more pieces. Audoly and Neukirch show several videos of this phenomenon. The also show that dry spaghetti breaks even if you just bend it, and release it suddenly. This is because the waves of curvature propogate through the spaghetti, and sometimes the curvature becomes too high. When you break spaghetti, it first breaks into two, and then the remaining halves behave as if they were released suddenly, splitting into further pieces.

Feynman quotes. BTW, Infinity – on the life of Feynman – would be a good movie to watch. Comments anony 3 Oct 2005 7:53 pm: This page is hell. Thise silly yellow things keep popping up. S Anand 4 Oct 2005 1:15 pm: Agreed. The popup shows the tags associated with the link. Any ideas on improving it?

Tough learning. Excellent article (speech, actually) by a physicist on how to learn. Very readable, and has a quote I won’t forget: “A change of perception is worth 80 IQ points.” Comments Ramesh 10 Sep 2005 9:50 pm: That was really a good article would highly recomment others to read the same Arun 11 Sep 2005 3:20 pm: Illuminating. Needed that right now.Thanks.

13 things that do not make sense From the New Scientist. Comments Jetru 17 Mar 2005 5:50 pm: Good one

Some (light?) reading on physics: Motion Mountain – a rather large and comprehensive physics book for download. And some links on Quantum Field Theory.

The Onion on the plans of top Indian physicists.

Quantum information science: a convergence of complexity theory and quantum mechanics. via missing matter

Good summary of superconductivity at kuro5hin.

For a few tenths of a second, at the micrometer level, the Second law of Thermodynamics can be violated. The interesting thing is that it happens at such a large scale.

On a similar note to movie physics, the science of superheroes

Good and bad physics in movies.

The sci.physics FAQs. Incidentally, energy is not conserved. Hot water freezes faster than cold water. And mirrors don’t swap left-right – they swap in-out.

A simple and detailed explanation for why evolution does not contradict the second law of thermodynamics.

Take two plates. Bring them very close in a vacuum. They will attract. The Casimir Effect (free subscription required).