Question:How can we communicate to distant parts of the Earth?
There are two main ways.
1.Satellites in orbit can receiver and retransmit signals from one Earth based antennae to another.
Microwaves are used for this purpose because microwaves pass straight through the Earth&aposs atmosphere. Microwaves only work when the the transmitter is on line of sight with the receiver.
2.Radiowaves are reflected by a layer of the Earth&aposs atmosphere called the Ionosphere, so they can reach distant parts of the Earth as shown in the underlying diagram. This is an example of Total Internal Reflection.