Comments on: Physics versus Fear

By: C’mon… « Punk Professor

C’mon… « Punk Professor — Tue, 11 Mar 2008 21:25:57 +0000

[...] Found here. [...]

By: Blake Stacey

Blake Stacey — Thu, 06 Mar 2008 16:42:08 +0000

It just occurred to me that one reason why a clumsy fellow like myself should go for the pendulum instead of the fire-walking is that, by conservation of energy, the pendulum can't come back to hit you more strongly than you accidentally pushed it.

By: Eamon Knight

Eamon Knight — Thu, 28 Feb 2008 18:23:05 +0000

What went unnoticed was that the student gave the ball a little push, rather than just letting it go â€¦

That’s the part that would worry me (and why I would insist on releasing the pendulum myself). Ditto for fire-walking. You can “prove” that the pendulum won’t hit you, or your feet won’t burn, using a mathematical model of the situation — but the real world tends to include, um, perturbations that often make things come out a bit differently.

By: Blake Stacey

Blake Stacey — Mon, 25 Feb 2008 23:13:24 +0000

“Arrr. The laws of science be a harsh mistress.”

By: Tom

Tom — Mon, 25 Feb 2008 22:18:10 +0000

There’s the (probably apocryphal) story that a professor did the pendulum demo in class, standing up against a wall, and got a student to give it a try. What went unnoticed was that the student gave the ball a little push, rather than just letting it go …

By: Jared

Jared — Mon, 25 Feb 2008 02:06:31 +0000

I love how Dawkins picks a girl to play Jesus…you can just sense the pleasure it gave him when he made that decision.

By: Blake Stacey

Blake Stacey — Sat, 23 Feb 2008 20:09:30 +0000

He uses himself as a pendulum bob at the end of lecture 10, and the staring-down-harmonic-death demonstration is at the end of lecture 11.

Dang, there are more goodies on OpenCourseWare every time I look.

By: Isabel Lugo

Isabel Lugo — Sat, 23 Feb 2008 19:43:34 +0000

Can't watch the video right now... but I wanted to point out that Walter Lewin does something similar with a pendulum in his freshman physics lectures as well. (I can't find it right now, but I definitely remember seeing it back when I spent some time watching those videos in December.)