Calculate the Speed of Light by Melting ChocolateS

You might already know that the speed of light is 299,792,458 meters per second, but now you can confirm that number by playing kitchen scientist and melting chocolate. And then eating the results.

The folks at Wired think that this physics experiment is ideal for all the leftover Valentine's Day candy, but I think it's great all year round.

This is what you'll be doing:

  • Make sure the candy is in a microwave-proof box. Better yet, take the chocolate out and put in a microwave safe dish.
  • Remove the turntable in your oven. (You want the candy to stay still while you heat it.) Put an upside-down plate over the turning-thingy, and place your dish of candy on top.
  • Heat on high about 20 seconds.
  • Take the chocolate out and look for hot spots. Depending on the candy you use, you may have to feel the candy to see where it has softened. With the cherry cordials we used, we saw several shiny spots and one place where the chocolate shell melted through, releasing the sweet syrup inside.
  • Measure the distance between two adjacent spots. This should be the distance between the peak and the valley (crest and trough) of the wave. Since the wavelength is the distance between two crests, multiply by 2. Finally, multiply that result by the frequency expressed in hertz or 2,450,000,000 (2.45 X 109)

Ta da. In this example, the final number was a bit lower than the actual speed of light, but it's still pretty darn close considering the difficulty of finding the exact "hot spots" to measure from. And the difficulty of sacrificing chocolate to science. [Wired]