How does light have energy? How can light exert force?

Question

Here is what I know:

Photons have no mass.

Force is change in momentum over change in time.

Momentum is mass times velocity.

E=mc²

SO HOW DOES LIGHT HAVE ENERGY AAAA

I also read that massless particles can have momentum and I do not understand that at all.

Please explain how all of this is connected and how light has energy and exerts force. Thank you!

In: 9

Answer 1

You’re referencing simple Newtonian equations and trying to apply them to light, but light is an inherently relativistic phenomenon. They just don’t go together.

Are you currently studying physics? If you are, it’s really important to keep track of what assumptions you make while deriving a particular equation, otherwise you may apply equations incorrectly. Not to mention, things will make a lot more sense in general.