Comments on: Marshmallows-A Take-Home Lab

Marshmallows-A Take-Home Lab

thatwhichfalls — Fri, 30 Apr 2004 09:02:55 -0800

via Making Light

By: me3dia

me3dia — Fri, 30 Apr 2004 09:14:06 -0800

That's really cool.

By: linux

linux — Fri, 30 Apr 2004 10:24:36 -0800

And yummy.

By: chicobangs

chicobangs — Fri, 30 Apr 2004 10:38:02 -0800

Wonder if it works for pudding. I like pudding.

By: jmd82

jmd82 — Fri, 30 Apr 2004 10:54:24 -0800

That is a nifty little trick! 6cm seems like a damn long wavelength, though when all I study in physics are light waves in the 10^-7 spectrum.

By: MetalDog

MetalDog — Fri, 30 Apr 2004 12:36:37 -0800

But he doesn't say anything about the student assessment. The lesson is useless unless you can measure achievement. I bet this teacher got fired.

By: andrew cooke

andrew cooke — Fri, 30 Apr 2004 12:56:55 -0800

you can also (i've seen his done, although it sounds terribly dangerous) put a normal lightbulb in a cub, metal cap down, with water covering the cap (to stop arcing). place it on the turntable and turn the microwave on - the light glows more and less brightly as it moves from nodes to antinodes in the standing wav pattern.

By: signal

signal — Fri, 30 Apr 2004 13:05:29 -0800

Can somebody give me a simple explanation of why the distance between the spots = 1/2 the wavelength? I understand it has to do with waves re-inforcing and cancelling out, but why 1/2?

By: jmd82

jmd82 — Fri, 30 Apr 2004 13:52:19 -0800

Another cool one I did in High School was take a 10 foot pipe that was about half a foot in diameter. Drills holes a few centemeters apart. On one end, attatch a speaker (be sure its sealed) and on the other end, hook up the Bunson Burner- once again ensuring its sealed. Turn on the burner and the music, put a match to one of the holes, and you got a sinutoital wave of fire.

By: nicwolff

nicwolff — Fri, 30 Apr 2004 15:40:36 -0800

signal: a standing sine wave is not a stationary wave, but rather a pattern of alternating nodes, which stand still, and antinodes, which alternate from high to low displacement. Microwave ovens are sized to create standing waves, and the antinodes are where the heat is generated. Since there are two antinodes in each wavelength - one high and one low at any given time - the hot spots are 1/2 the wavelength apart.

By: nicwolff

nicwolff — Fri, 30 Apr 2004 15:42:42 -0800

This image from the linked article tells the whole story so I'll just drop it in here:

By: starkeffect

starkeffect — Sat, 01 May 2004 13:11:29 -0800

More fun microwave experiments.