Electromagnetic waves on the plate? Although we don't eat enough that worth look at it.

James Clerk Maxwell had concluded that the electromagnetic field can exist without the charges and currents since he formulated the theory of electromagnetism. However, the change of the state of the field must has wave character. These type fields called electromagnetic waves. H. R. Hertz used Ruhmokorff induction coil, antennas with other various shape and he observed spark-over using microscope when he was searching "Maxwell's waves" in 1887. This experiment can repeat using the piezoelectric transducer which is lighter for gas and small neon indicator. The lighter linked with antenna in the form needles.

The receiver is from two identical needles connected by neon indicator, situated parallel and 5 - 30 cm away from transmitter. The needles have to be isolated from the ground. Push the lighter causes switch on the neon. With help this simple experiment we can observe that electromagnetic waves transmission not only information, but also energy.

The currents in the piezoelectric effect aren't much, but voltage is order 10 kV. The piezoelectric effect consist in polarisation dielectric under influence its deformation, what lead to appearance on its boundary potential difference. The instance of the material which shows the piezoelectric effect is a quartz. The piezoelectric effect found widely application for convert of the electrical vibrations into the mechanical ones and vice versa.