Yes, gravity does affect the speed of light. However, the effect is very small. In a vacuum, light always travels at the speed of 299,792,458 meters per second (186,282 miles per second). However, when light passes through a region of space with a strong gravitational field, such as near a black hole, its speed can be slightly decreased. This is because the curvature of spacetime caused by gravity can slow down the motion of light.

The amount of change in the speed of light due to gravity is very small. For example, the speed of light near the surface of a black hole is about 300,000 meters per second slower than the speed of light in a vacuum. This is a very small change, but it is still measurable.

The effect of gravity on the speed of light was first predicted by Albert Einstein in his theory of general relativity. General relativity is a theory of gravity that describes gravity as a curvature of spacetime. According to general relativity, the presence of mass curves the fabric of spacetime, and this curvature affects the motion of objects, whether they have mass or not.

The effect of gravity on the speed of light has been confirmed by several experiments. For example, in 1919, Arthur Eddington observed that the light from stars passing near the Sun was slightly bent. This bending of light was caused by the curvature of spacetime caused by the Sun’s gravity.

The effect of gravity on the speed of light is a very small effect, but it is an important one. It is one of the predictions of general relativity that has been confirmed by experiment.