Short Nerd Chief

Some physics links (sort of):

1. Wikipedia’s page on Cartoon Physics, including a discussion of Anvilology and Collision Physics.  Scroll to the bottom for some laws of cartoon dynamics:

• Any body suspended in space will remain in space until made aware of its situation (plus an interval for live falling bodies to express an appropriate emotion).

• Any body in motion will tend to remain in motion until solid matter intervenes suddenly.

• Any body passing through solid matter will leave a perforation conforming to its perimeter.

• All principles of gravity are negated by fear, surprise and/or shock.

• Falling bodies either collide with the earth completely elastically or inelastically. If the collision is elastic, the energy will be ultimately transferred to something else which collides absolutely inelastically (e.g., into a hanging cliffside that cracks and falls).

• Momentum is continual until noticed.

• Bodies can achieve energies greater than they originally started with, even if no external force is added (e.g., a rock will, when rolled against a ramp) fly higher than its original starting point.

• The amount of work on rocks falling tends towards zero (i.e., they tend to fall to their original (!) starting point).

• As speed increases, objects can be in several places at once, a situation similar to the ones described by quantum mechanics. Or a character running wildly will meet him- or herself face to face.

• Everything falls faster than an anvil, except for an agent attached to an anvil by parachute strings, in which case the anvil tows the agent.

• Arms holding large falling weights are infinitely elastic, but will eventually drag the holder along.

• Protocol or photo opportunities will suspend the motion, not only of persons running, but also of inanimate objects.

• Tools and machinery also behave in unusual ways. An old-fashioned bumper jack, raised or lowered with a long lever, will exceed by many times the height of its own housing (similar to hammerspace) when a character needs it to lift something to a considerable height. Also, lazy tongs can be manufactured to reach over considerable distances.

[etc.]  Study of cartoon physics has a long and glorious history, with researchers ranging from Stephen R. Gould to Roger Ebert.

2. Insultingly Stupid Movie Physics (now a book!).  Don’t miss the review of the worst movie physics of all time, in the otherwise execrable The Core:

There is little reason to panic over a magnetic field upset. The geological record indicates Earth’s magnetic field reverses itself at irregular intervals averaging about every half a million years. While the magnetic field probably doesn’t drop to zero during these times, available evidence suggests it becomes weak and erratic. Undoubtedly, some bad things happen but there’s no evidence that such fluctuations cause mass extinctions, let alone incineration by deadly microwave radiation.

The movie’s heroes set out to solve this horrifying non-problem in the only possible way: send a manned vehicle that looks like a windowless subway train into the Earth’s core and blow up five 200-megaton nuclear bombs. (We always knew nukes were good for something.) An unmanned vehicle would make a lot more sense for such a hostile environment, but then the movie’s heroes would not be able to exhibit courage, daring, and self-sacrifice….

The solid iron inner core normally has a rotational kinetic energy equivalent to about 340 200-megaton bombs. The liquid metal (primarily iron) outer core surrounding the inner core has a normal rotational kinetic energy equivalent to roughly 32,000 200-megaton bombs. Assuming only the inner core had to be restarted and that 100% of each bomb’s energy could be converted to rotational kinetic energy, the movie’s heroes are at least 335 bombs short of the required amount.

[Wikipedia link via Google Blogoscoped]