How does a remote send commands using invisible light?

Press a button across the room, and the television changes. No wire joins your hand to the screen. An infrared remote sends the message using a kind of light our eyes cannot see.

Inside the remote, a tiny light source flashes in quick bursts. A button selects a pattern of bursts and gaps. One pattern can mean turn on; another can mean change the volume. The pattern is a code, like an agreed message made from flashes instead of spoken words.

A receiver on the television notices the incoming light and turns it into an electrical signal. The television's control checks for a command it understands, then carries out that command. The light does not push a switch or supply the energy that runs the whole television. It carries information.

A solid object can block the light's route. Then the matching message may not reach the receiver, even though the button was pressed. Some remotes use other kinds of signals, but an infrared remote gives invisible light a very familiar job: carrying a little instruction across a room.