Does light occupy space?


My son wants to know how we can perceive light and it not take up any space at the same time.

In: 161

I don’t know a good way to explain this to a literal child, but here’s my best attempt:

Light comes in individual little bits that we call photons. Photons are little points, literally so small they have no length or width or depth. However, despite being little points, they still carry energy. When they hit things, they transfer that energy. For example, photons from the sun will hit your skin and you’ll feel that energy as heat. Your eyes are just fancy machines that uses all the little photons hitting it to paint a picture of the world.

Light is made of energy (Electromagnetic radiation) so it doesn’t have any matter (atoms) to occupy space

In a very very oversimplified statement, only things with Mass can interact with space.

Things without mass like photons can only interact with objects in space.

No. In fact, most things don’t actually occupy space.

Electrons refuse to share space with other electrons, but a photon or neutrino can pass right by.

The idea that a thing may be solid and occupy space makes sense to us because it seems true in the world of big things, but in the world of very small things it isn’t true anymore.

Light has a size (the wavelength), but the pieces of light are allowed to overlap with each other. So it exists in space, but doesn’t “take up” the space in the sense of preventing other light from being there too.