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Measure The Speed Of Light With Your Microwave
maddmike writes "There is a very interesting article on About.com that shows how to measure the speed of light using your microwave to melt chocolate. "
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Just try to measure the speed of dar. . .
Oh, nevermind.
KFG
...don't try this at home. Theobroma cacao (chocolate) is a highly dangerous substance with known stimulant effects. It is also highly addictive and should be used with extreme caution. Overdose can cause morbid obesity, sluggishness, and death. Only qualified experts should handle this dangerous reagent at home.
I am experienced at handling this most hazardous material. Please wrap it carefully in a heatproof container, and mail it to me. It will be disposed of properly. (burp)
Honey, I shrunk the Cygwin
There is a very interesting article on About.com that shows how to measure the speed of light using your microwave to melt chocholate.
Big deal...I can measure Hubble's Constant by charring bagels in my toaster. Pffft.
I was just writing a wikipedia page yesterday on Famous Experiments, and that's the one I added. I read that Galileo tried measuring the speed of light the same way they measured sound -- by having two people stand a large distance apart, and flash a latern (for light) or make a sound. Subtract out the handler delay (a known quantity dependant on the person), and divide by two to get the speed of the wave. This works rather well for sound, but never worked for light.
To make laws that man cannot, and will not obey, serves to bring all law into contempt.
--E.C. Stanton
Short informative read:S peedOfLight/measure_c.html
http://math.ucr.edu/home/baez/physics/Relativity/
...Your Local Fire Department by placing some metal in your microwave and putting a blanket over it. =P
Anyone can melt chocolate or heat water in their microwave.
Real geeks use microwaves for what they were intended for... nuking free trial CDs from AOL.
You cannot do it by measuring the dimensions of the magnetron cavities, because the calculation of the frequency based on dimensions assumes the thing you are trying to work out - the speed of light. Frequency counters that go up to 2.5GHz are a bit difficult to come by in most homes. One possibility might be to extract some energy from the cavity using a suitable antenna and mix it with the clock signal from a 2.4 or 2.53GHz motherboard, then try and pick up the resulting beat signal using a short wave or VHF radio. However, I'm not at all sure how to get the signal out of the P4.
Has anybody got a better and reasonably practical method of measuring the frequency?
Panurge has posted for the last time. Thanks for the positive moderations.
Summary of the method used in the article:
* Slightly melt chocolate chips in your microwave
* Measure distance between melted spots
* This gives you (half) the wavelength of your oven
* Multiply by the frequency of your oven, you get the speed of light
That's certainly interesting, but guess what? Many scientists have done better (and much more expensive) measures, so we already know the speed of light quite well.
What we might not know as well is the frequency of your oven. So I suggest you reverse the above formula, and you measure the frequency of your oven (not always printed on the back, as the article admits) this way.
Speed of light approx 300 000 km/s = 3E8 m/s.
Actually, the easiest way to measure the speed of light is to measure the interval between the lights turning green and the first cab horn sounding during the morning rush hour in Manhattan, then measure the distance from the lights to the cab.
Neither original nor practical, but then I am tired and this is /.
Panurge has posted for the last time. Thanks for the positive moderations.
maddmike writes "There is a very interesting article on About.com that shows how to measure the speed of light using your microwave to melt chocholate. "
Bah, that's easy stuff. It's about time that About.com tackled the real holy grail of science - how to teach Slashdot editors to use a spelling checker.
"Accept that some days you are the pigeon, and some days you are the statue." - David Brent, Wernham Hogg
>could someone please provide me with the equation if mine has a turntable?
Step [1]: Using a highly detailed tool (1) you will first wrap around a plastic groove on the front of the microwave. You will then use this tool (1) putting a few newtons of pulling force translaterally against the groove. Too much pressure here may be dangerous, so use caution. If your microwave has no such groove, you'll press tool (1) against a reverse indentation on the front of the microwave using at least a few newtons of pressure. Overuse of pressure is not a danger when using the correct tool (1).
Step [2]: At this point you'll be able to access the inside of the microwave. If you cannot access the inside of the microwave at this point, you have not successfully completed step [1]. Please attempt it again as necessary to access the inside of the microwave. Once access has been gained, you will use tool (1) to grip the edges of the glass object inside. Do not grip the glass object extremely tightly or it may be damaged! Now, using tool (1) exert an upward pressure to the glass object, causing it to levitate to the middle of the microwave (this point will vary depending on model).
Step [3]: You must complete step [2] to continue to this step. If you are at this step, you are now gripping a glass object centered in your microwave. Pull this object towards you with tool (1). Continue to move this object and rest it on a flat, cool, surface. Ungrip the object. Using a choice of tool (2), exert a reverse pressure on the item disloged in step [1]. Continue to extert this pressure until a click is heard.
Step [4]: There is no step [4]. If you have completed step [3], your microwave is now ready for the experiment in the article.
Required Tools:
(1) fingers
(2) hand
Optional Tools:
(3) brain
(4) article
If you could be told what you can see or read, then it follows that you could be told what to say or think - BoC
It's 3x10^8 m/s
If I seem short sighted, it is because I stand on the shoulders of midgets
Some brave souls try to correct me by pointing out that "the microwave particles" are so small they can't be seen, so are clearly smaller than the holes.
I then introduce the notion of particle/wave and laugh as I watch them go completely blank...
I was about to attempt this fascinating experiment but my stomach had... other plans
Couldn't they have created this experiment with something less tasty, like broccoli?!
Business \Busi"ness\, n.;
A scam in which all people involved perceive as beneficial...
You can always use your network cables instead; brief description or full paper.
Anyone care to use the method with RFC1149 Avian Carrier Protocol, namely Using Ping to determine Speed of Flight!
Andrew Yeomans
you're wrong, or at least outdated: http://lamar.colostate.edu/~hillger/meter.htm
There was this episode of Mystery Science Theater 3000 (Secret Agent Super Dragon?) where the main character flips a light switch, and about half a second later the light dimmed down. Crow said "Light travels slower in his world". Heh.
Hmmm.. sorry guys, it really is more of a visual joke.
"Derp de derp."
measuring the speed of microwaves, not light
Microwaves are light. They just have a longer wavelength. The speed is the same as for visible light. It is only dependent upon the medium.
if it needs 2 minutes to melt some chocolate, that's not very fast.
Otoh, I wholeheartedly agree with this statement.
"I assumed blithely that there were no elves out there in the darkness"
You can also measure the speed of light using ants, the ants are small enough that they can fit into the low energy points of the microwave.
If you put some ants in the microwave, and switch it on, they all start moving from the heat into the cold spots, measure the distance between the cold spots and you have the wavelength.
Obviously, you shouldn't *actually* try this, unless the ants happen to climb in there looking for food, then they're fair game :) And take the turntable out, that's cruel.
The calculation (chocolate or ants) does still rely on prior knowledge of the frequency of the microwave(s) being used. Trying to measure the speed of light without a prior fixed frequency or wavelength is much more taxing. A shortwave radio can help though, or a flashlight and a large telescope (bouncing signals off the moon)
You didn't measure the speed of light, you measure a wavelength. Unless you can show that you had some way to confirm the frequency of the light source that is not dependent on knowing the speed of light, then when you looked up the frequency of the light source you were effectively looking up the speed of light and using it to determine the speed of light. No wonder your answer came out close!
I'm an American. I love this country and the freedoms that we used to have.
This only works if you can stop the mechanism by which the microwaves are scattered around to make for even heating. If you have a turntable in the bottom of your microwave, then removed it might do the trick, but most microwave ovens have a rotating metal "fan" that is enclosed in the upper surface over the cooking cavity, and that metal fan spins to scatter the waves around -- think of it like a flashlight and a mirrored pinwheel. Hence no turntable is required.
I'm not aware of any way of disabling that "fan", although I suppose you could drill a tiny hole in the shroud and poke in something to stop the spin, a la stopping a grinding PC fan. But I personally am not terribly interested in poking a drill into a microwave oven ...
One simple rule for its versus it's