Microwave and Radio-Frequency Technologies in Agriculture

4 Microwaves and their Interactions with Materials

The earth has three important fields associated with it. Two of these fields are obvious and taken for granted, the other is important, but not so obvious to the casual observer. The obvious fields are: the gravitational field and the magnetic field. The not so obvious one is the electrical field that exists between the surface of the earth and the ionosphere, which is high in the atmosphere. Interestingly, the gravitational field is the weakest of all field forces. The main reason that gravitational fields are so obvious is because planets and stars are so massive and therefore manifest large gravitational fields. The magnetic field is strong and protects the earth by deflecting charged particles ...