A Nibble of Binary

The state of a light, being either on or off, can be used to communicate or store information.

For example, each light of a traffic signal has a meaning.

Combinations of lights can also have meanings. In the UK, for example, red and yellow together indicate that the green light is about to turn on.

In fact, there are eight possible combinations. Many of them are not used, but each could have a meaning.

With four lights instead of three, there are sixteen possible combinations. These combinations can be used to represent the numbers from zero to fifteen.

Of course with more lights, more numbers can be represented. With eight lights, 256 combinations are possible.

Questions, comments, or corrections welcome!