What particle can travel at the speed of light?

When it comes to speed limits, the ultimate one set by the laws of physics themselves is the speed of light.

When scientists talk about the speed of light — 299,792,458 m/s — we implicitly mean "the speed of light in a vacuum." Only in the absence of particles, fields, or a medium to travel through can we achieve this ultimate cosmic speed. Even at that, it's only the truly massless particles and waves that can achieve this speed. This includes photons, gluons, and gravitational waves, but not anything else we know of.

More Info: www.forbes.com

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22 Comments

Rajnish Gautam

Neutrino has also the same speed of light. See https:/www.nationalgeographic.com

Kenneth Jacobs

It is true enough the a photon travels at the speed of light. More recent evidence also suggests that a neutrino travels at the speed of light without the interruption of solid mass. Perhaps "neutrino" should not have been used as a possible answer for this particular question.

sftcw

Light is composted of photons. So, of course, photons travel at the speed of light.

Gery Tillmanns

Neutrinos also a correct answer.

John Lazier

Both Neutrinos and photons can travel at the speed of light Two correct answers Bad choices for answers

Liz Hamilton

Both neutrinos and photons are correct answers. Perhaps the writer is getting technical - photons travel at the speed of light and neutrinos travel faster than the speed of light. Not a good question at all.