Tuesday, February 16, 2010

Leftover Valentine’s Chocolate? Use It to Measure the Speed of Light

Wired: "If you’re a long-time reader, you may remember the great leftover Easter Peeps microwave experiment. Well, today we’re going to be nuking leftover Valentine’s Day chocolate to demonstrate one of the constants of physics, the speed of light. Chocolate makes a very appropriate medium, because the heating property of microwaves was first discovered by a scientist whose candy bar melted in his pocket when he got too close to a microwave device being tested for use in radar.
WARNING: This experiment may take several tries to get right. We are not responsible for any weight gained. To avoid familial strife, be sure to only do this experiment with your own chocolates or with candy which you have been authorized to access. You can probably find some leftover boxes on sale this week.
The demonstration works because microwave ovens produce standing waves — waves that move “up” and “down” in place, instead of rolling forward like waves in the ocean. Microwave radiation falls into the radio section of the electromagnetic spectrum. Most ovens produce waves with a frequency of 2,450 megahertz (millions of cycles per second). The oven is designed to be just the right size to cause the microwaves to reflect off the walls so that the peaks and valleys line up perfectly, creating “hot spots” (actually, lines of heat)."

Read More http://www.wired.com/geekdad/2010/02/leftover-valentines-chocolate-use-it-to-measure-the-speed-of-light/#ixzz0fjpghQkj

No comments:

Post a Comment