# What is the effect of gravitational field on an object moving at the speed of light? [closed]

If a body moving at the speed of light moves towards another stationary body having much greater mass then,this body makes the moving body to accelerate under its gravitational field in such a way that when the moving object is infinitely close to the stationary object its speed is much greater than the speed of light for a infinitely small fraction of a second. Now the object should travel backwards in time, at the start of that infinitely small second. The same process would repeat. This means that the object would appear still in front of the stationary object?

Is this assumption hypothetically right?

• It cant move faster than the speed of light. Accelerating something massive to c requires an infinite amount of energy – Jaywalker May 12 '17 at 15:39
• Its an hypothetical assumption. – Kurosaki May 12 '17 at 15:42
• Yeah but theres no point in asking a question based on a hypothetical assumption thats not rooted in physics – Jaywalker May 12 '17 at 16:26
• Then according to you , Theory of Everything , string theory and multiverse theory developed by some brilliant scientists of the world are not part of physics because they are hypothetical? – Kurosaki May 12 '17 at 16:37
• He said "rooted in physics". The list you give "Theory of Everything, string theory...etc" is rooted in physics and they could be possible. Moving a massive object faster than light has been deemed impossible. – Brad S May 12 '17 at 16:59

This question is somewhat answerable, though. Photons (and other particles of mass $m=0$) do move at the speed of light, and when they get close to very massive objects, like stars, they are influenced by gravity and their trajectory bends. However, the photon does not speed up. It accelerated in the sense that its direction of motion changes, but it still moves at the speed of light regardless.