I Didn’t Know That...

Q: Why do metal objects create sparks when placed inside a microwave oven?

A: Because they are good electrical conductors, according to physicist Collier N. Smith of the National Institute of Standards and Technology. Metal objects act like antennas in the ovens, picking up the intense electromagnetic field used to cook food. This process produces a large electric charge in the conductor, which can arc to the wall of the oven, creating sparks. This in turn could cause a fire or otherwise damage the interior of the oven.