Are there any particles that can also travel at the speed of light, like photons?

Question

They would have to have no mass, I know that. I just don't know if there are any.

Answer 1

protons and electrons.

Answer 2

tachyons?

Answer 3

Neutrinos were the last particle thought to be massless, but experiments in 1999 showed that they possessed at least a tiny amount of mass.  So, these things travel a tiny bit less than the speed of light.

Only particles that carry a force of infinite range have massless particles associated with them.  Electromagnetism is an infinite-range force, so its associated particle, the photon, must be massless.  Gravity is also infinitely-ranged, implying that the hypothetical graviton--the particle that mediates the gravitational force--is massless.

Answer 4

Maybe.. Around 0.02% can travel at that speed.

Answer 5

not in practical

but theoritically there is one thing:TACKION.................

A tachyon (from the Greek ταχύς takhús, meaning "swift") is any hypothetical particle that travels at superluminal velocity. The first description of tachyons is attributed to German physicist Arnold Sommerfeld, but it was George Sudarshan and Gerald Feinberg (who originally coined the term) in the 1960s who advanced a theoretical framework for their study. Tachyons have recurred in a variety of contexts, such as string theory, and in science fiction. In the language of special relativity, a tachyon is a particle with space-like four-momentum and imaginary proper time. A tachyon is constrained to the space-like portion of the energy-momentum graph. Therefore, it can never slow to light speed or below.