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
