Question

How can photons travel at the speed of light if they have some mass?

Answer 1

Photons don't have any mass, you were misinformed.
They do have momentum and are affected by gravity, but this is because of relativistic effects.

Answer 2

According to Einstein's equation anything which has mass cannot travel at the speed of light its mass will become infinite

Answer 3

But photons don't have mass, so they're cool

Answer 4

Photons have a negligible mass. In acse they didnt they would not have been affected by gravity, and we know light bends around strong magnetic fields

Answer 5

Sorry, not magnetic, gravitational

Answer 6

Photons are affected by gravity because of general relativity. They are affected because mass bends the space through which the photons pass, not because of the classical \[F=Gm_1m_2/r^2\]force. This was the big triumph of general relativity.

Answer 7

But we are not really sure about photons. They may or may not have mass. Unless you take Einstein to be right at any cost.

Answer 8

That's true. We never really know for sure. But we have pretty good evidence for photons being massless, and don't really have any saying they do have mass. So for now I'll believe the standard explanation