C is for chocolate. Microwave for a few seconds until the chocolate starts to melt it only needs melting a little bit ie. You can use chocolate cheese or even marshmallows to microwave at the speed of light.
Use a ruler to measure the distance between the centres of the two melted points.
To determine the wavelength place a large sacrificial slice of cheese or chocolate bar on a plate. A bar of chocolate actually get three that way you know youll actually get to do the experiment. Distance between two melted spots of chocolate x 2 x 2450000000 z. Microwave for a few seconds until the chocolate starts to melt it only needs melting a little bit ie.