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can only photons travel at the speed of light?
can a particle that has mass travel at c?
can a particle that has mass travel at c?
Originally posted by Dave
Neturinos, if you believe in them...
Originally posted by leoant
hehe
is photons travel in the speed of light?what is the difinition of the speed of light? isn't the speed of the free photons?
do photon have mass? if not, why there is the effect of the light pressure? and i think it has ,and i think the mass is the carrier of momentum and energy.
and i think if we redifine a limit of speed(theoretical light speed?) ,the speed of photons cannot make it,and all things or particles cannot
Originally posted by sdeliver645
I wanted to correct some of the statements others have made and answer a few of the questions that came up in response to particles traveling faster than c. Some of these answer have already been clarified by Peter_C. Note that I am NOT answering any of these questions based on a "guess" or a cool dream I had or an Isaac Asimov book. If I am unsure, I will let you know and not mislead anyone. Also, please correct me if I am wrong.
1.
"a type of theoretical particle that can travel faster than c"
These particles are indeed theoretical, in the sense that someone conceived of them simply to make physics look more symmetrical. These particles are called "tachyons" and have NEGATIVE MASS. Note that this hypothetical negative mass is DIFFERENT from the negative EFFECTIVE mass you define in a crystal lattice for electrons and holes. I will stress that, to the best of my knowledge, there is NO THEORETICAL EVIDENCE to support their existence.
Originally posted by sdeliver645
Tyger, you must be a particle physicist by the look of your units (hbar=c=1).
Thanks for the correction, indeed you are right!
No, according to the theory of relativity, photons are the only particles that can travel at the speed of light, also known as the speed limit of the universe.
Other particles have mass, which means they require energy to move. As an object approaches the speed of light, its mass increases, making it more difficult to accelerate and ultimately impossible to reach the speed of light.
No, according to the theory of relativity, the speed of light is the maximum speed at which anything can travel. Photons are massless particles, so they can reach this speed without any increase in mass.
Yes, photons can be slowed down by passing through a medium, such as air or water. This is due to the photons interacting with the particles in the medium, causing them to temporarily lose energy and slow down.
The speed of light is a fundamental constant in the fabric of space-time. It is the same for all observers, regardless of their relative motion. This is one of the key principles of the theory of relativity.