Some light energy can be seen and some cannot be seen with the unaided eye.
There is one type of light energy that is virtually everywhere in most American cities, but it is invisible to the unaided eye. It has a wavelength so long that it can pass right through buildings, and even through human beings, without any trouble. This type of light is used to transmit information long distances, since very little interferes with it, and it can be easily captured by receivers.
Humans have used this type of light energy for many years to transmit and receive many different types of information. The technology to use it is so widespread that it is in almost every modern car, truck, and home.
What type of light energy is this?
A.
ultraviolet
B.
radio
C.
gamma
D.
X-ray