312. Can microwaves be emitted to travel in one direction?
Yes. Like all electromagnetic waves, microwaves can be focused and concentrated in a particular direction. That is exactly what microwave dish antennas (e.g., satellite dishes) do. At the transmitter, they focus the microwaves emitted by a smaller antenna so that those microwaves travel as a parallel beam. At the receiver, they focus the parallel beam of microwaves onto a smaller antenna. You can think of the microwaves as very long wavelength light waves, so that anything you can do with light (e.g., focus it, form images with it, or bend it with optical devices), you can also do with microwaves. The only problem is that the optical elements you use for microwaves must be larger, because the microwaves have longer wavelengths.