system
Given the following post, respond as if you're commenting on Reddit:
human
How does light exist if it has no mass?

So, in my Chemistry class today we were discussing light as both a particle and as a wave. And so my teacher goes on and says that light, as a particle has no mass. I then inquired to figure out how something with no mass can still exist, to which she stated that energy has no mass so that is how it exists. My brain is full of confusion so i'm wondering if you could unscramble the mess about light.
gpt
The full energy equation is:

E^2 = p^2 c^2 + m^2 c^4

If you set mass to zero, you can still have objects that carry momentum and energy without mass. Such an object would always have to propagate at the speed of light.

Light isn't really well defined in words, since we don't have anything from our daily existence to compare it to, but we do know all the necessarily math to describe its behavior.