An experiment for the dessert

An electromagnetic wave on a plate? Why not! You cannot eat it, but you can observe it.

After formulating the theory of electromagnetism, James Clerk Maxwell came to a conclusion that the electromagnetic field can exist without charges or current. It should possess the characteristics of a wave. Such fields are called electromagnetic fields. H. R. Hertz, when searching for 'Maxwell's waves' in 1887 used the Ruhmkorff spark coil as the transmitter and some aerials of various shapes. He observed the spark-over with a microscope.

This experiment can be carried out again. We need a piezoelectric gas spark and a small neon bulb. We connect the transmitter aerial made of knitting needles to the spark. The receiver is made of similar wires connected to the neon bulb or a LED. The device is placed on a plate, which provides very good insulation.