WHAT IS LIGHT?

Light is made up of little packets of energy called photons. Most of these photons are produced when the atoms in an object heat up. Heat “excites” the electrons inside the atoms and they gain extra energy. This extra energy is then released as a photon. The hotter an object gets, the more photons it gives out.

HOW DOES LIGHT TRAVEL?

Light travels as a wave. But unlike sound waves or water waves, it does not need any matter or material to carry its energy along. This means that light can travel through a vacuum—a completely airless space. (Sound, on the other hand, must travel through a solid, a liquid, or a gas.) Nothing travels faster than light energy. It speeds through the vacuum of space at 186,400 miles (300,000 km) per second.