Seeing Where the Microwaves Are in a Microwave Oven

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Published 2010-11-11

Microwaves are absorbed by wires creating current in the wires which can drive a neon lamp like this guy en.wikipedia.org/wiki/File:Neon_lamp.jpg. I drilled a grid into a piece of plastic and slipped in the bulbs, leaving the wires to hang out like antennas. As the plate turns, the bulbs go into and out of places where the microwave energy is denser, illuminating the bulbs. No, it doesn't seem to hurt the microwave. You can find out more about how to make this by going to kossover.squarespace.com/journal/2010/11/12/seeing….
Edits: I do seem to suggest that microwaves are only absorbed* by things that conduct electricity. That's not true, of course. The changing electromagnetic field of the microwaves will oscillate anything that has a charge or is polar. I was trying to point out that microwaves can move electrons in wires. Even slightly salty water does seem to heat faster in my poorly controlled experiments, though.
"Absorbed" isn't quite the correct term, I know.

Oh, and kids, don't try this at home without your parent's permission. Many things do not like going into a microwave and will catch fire or spark or both. Your parents will be mad, and the fire department will be annoyed as well.

Marc "Zeke" Kossover, physics and environmental science teacher, The Jewish Community High School of the Bay, San Francisco, California

All Comments (21)

@JoachimFosse 4 months ago

This demo really shows why you dont want to place food items directly in the center of the microwave for optimal heating! Awesome
@peosborne 13 years ago

so precious! I love the transparency of the guys nerves when he explains everything! super cool video.
@zkossover 13 years ago

@dongor94 The neon bulbs work particularly well because they are so simple, cheap and small. Fluorescent tubes do glow in microwaves, but the electronics in a compact fluorescent bulb would get fried. I haven't put a halogen bulb in. I've put smaller incandescent bulbs (like flashlight bulbs) and they glow briefly and brightly until they burn out.
@l30njam3s 11 years ago

I honestly never thought i'd find something educational on youtube... nice vid
@JnAStudios 13 years ago

This is frickin' awesome! Thank you for doing this!!
@ManaYuGiOhGX5Ds 13 years ago

This is incredible and informative! Awesome!
@lazkataz 13 years ago

sweet vid koss! very cool!
@TimonWanga 13 years ago

good work, man. i dont know what you did this for (school project, fun, etc.), but well done.
@Anna8800 1 year ago

imagine watching this 11 years later
@Triberius 13 years ago

Love the leaking radiation causing the the camera to "fuzz" out the grid turns inside.
@BrotherOrchid 13 years ago

This was his PHD dissertation, now he can work for Dr. Venture.
@1ElleEm 13 years ago

Ah ha! I have this exact same microwave and it does heat better on the edges. Nice to see proof. Interesting to see a load effect with the water when it then only lights up when it passes the magnetron. Bet this becomes some kind of diagnostic tool; you better patent it if it's your own idea. Good job!
@loogel 13 years ago

This is very very cool. You also have an excellent voice.
@Laa1213 1 year ago

Beautiful microwave!
@Umplestiltskin 13 years ago

NO HE'S MY TEACHER! EVERYONE BE JEALOUS HE TEACHES US
@badpioneer 13 years ago

Kitchen light show! Super neat!
@TrustInTheShorts 13 years ago

Everything about this video is good with the exception of the narrator
@yinyue88 13 years ago

this is pretty cool! good job :)
@TheAdLab 13 years ago

Free house party disco lighting! Seriously though, that was a cool video.
@n0lanv0id 11 years ago

Awesome video. Way cool to see.