Even Without A Mass, light is affected by gravity

Contrary to what we always study at school, light is affected by gravity, even with no mass, and it does not always move in straight line.

Light does not have a mass, but its path is still affected by things that have mass, such as the sun.

So if a beam of light from, say, a far off star passes close enough to the sun, it will bend slightly around it. The effect on an observer such as us is that we see the star in a different spot of the sky than it’s actually located, much like fish in a lake are never in the spot they appear to be. So next time you look up at the stars, it could all just be a trick of the light.

This phenomenon is known as Gravitational lensing.

Read More: https://thetelegraff.com/light-affected-gravity