You probably know the speed of light is 299,792,458 metres per second. What does that mean in layman's terms? According to At-Bristol's Ross Exton, you can prove the speed of light... using chocolate.
Set up the apparatus
You need a microwave and a smooth bar of chocolate.
Remove the dish from the microwave. A microwave works by transferring energy via invisible light waves into your food. These waves, like any light wave, have a fixed length and this distance can be determined by where food gets hottest.
Melt the chocolate
Check what frequency your microwave is. This will be in megahertz or millions of waves per second. If you barely melt the chocolate, so the highest and lowest points of energy can be seen by what melts, the length of a wave (wavelength) can be determined. Cook the chocolate for 15 seconds.
Measure and compute
Measure the distance between the centres of two of the melted points. Double this distance to compute a full wavelength. Using this length, and how many waves per second are being produced, multiply the two to obtain the distance travelled each time. This is the speed of light.
Troubleshoot
If your number is way off, be sure you multiplied the number you got from your microwave by one million. If it's in the ballpark, remember that a ruler will make mistakes. And remember that the 3 x 108mps number quoted above is the speed of light in a vacuum; in our atmosphere it will be a little lower.
This article was originally published by WIRED UK
