# Can light bend the space fabric?

Mar 21, 2018

The space fabric can bend light due to gravity

#### Explanation:

It is interesting to speculate if light can bend space. We know that light can be bent by the space fabric.

Mar 21, 2018

Yes, light can bend the fabric of spacetime.

#### Explanation:

Einstein's field equations of General Relativity look very simple:

${G}_{\mu \nu} = \frac{8 \pi G}{c} ^ 4 {T}_{\mu \nu}$

The equations are far from simple. It is actually 10 second order partial differential equations which are very hard to solve. The left hand side is the Einstein tensor which describes the shape of spacetime and how it tells matter and light to move.

The $T$ term on the right hand side is the stress-energy tensor. It describes how mass-energy and momentum tell spacetime how to curve.

We know that the equation $E = m {c}^{2}$ says that mass and energy are equivalent. We also know that mass causes gravity by curving spacetime.

The term $\frac{8 \pi G}{c} ^ 4$ is very small. This says that it is very hard to curve spacetime. It takes a lot of mass to have a noticeable effect.

As light has both energy and momentum it too must cause spacetime to curve. The effects will however be very small.