How can photons travel at the speed of light?
Photons travel at the speed of light. A photon is type of elementary particle. The quatum of the electromagnetic field including electromagenetic radion such as light, and the force carrier for the electromagnetic force. The photon has zero rest mass and always moves at the speed of light within a vacuum.
Why do massless particles travel at the speed of light?
These massless particles have some unique properties. They are completely stable, so unlike some particles, they do not lose their energy decaying into pairs of less massive particles. Because all their energy is kinetic, they always travel at the speed of light.
How can photon have no mass?
Why do photons have no mass? In short, the special theory of relativity predicts that photons do not have mass simply because they travel at the speed of light. This is also backed up by the theory of quantum electrodynamics, which predicts that photons cannot have mass as a result of U(1) -gauge symmetry.
How do photons exist without mass?
Since photons (particles of light) have no mass, they must obey E = pc and therefore get all of their energy from their momentum. But an object with zero energy and zero mass is nothing at all. Therefore, if an object with no mass is to physically exist, it can never be at rest. Such is the case with light.
Can a photon travel at the speed of light?
As Luboš said, only objects with zero mass can travel at the speed of light, otherwise the energy would be undefined. which says that energy comes from both mass and momentum. So even if a particle has no mass, it can still get its energy from momentum, and photons do indeed have both energy and momentum.
Why does a photon have no mass?
The whole concept of a photon has no mass is bullshit if you accept E=MC squared. If M=0, the photon has no energy. Also, according to relativity, it takes infinite energy for any object with mass to travel at the speed of light.
What happens to mass as it approaches the speed of light?
If you accept E=MC2 then as a particle matter approaches the speed of light it is converted into energy the original mass being spread out infinitely as it is converted into energy. The reverse should also be true where as energy slows down by whatever mechanism the energy would revert to matter.
How does gravity affect light (photons)?
There are two important concepts here that explain the influence of gravity on light (photons). where $m_0$ is the rest mass of the particle (0 in the case of a photon). Hence this reduces to $E = pc$. In other words, a photon does have relativistic mass proportional to its momentum.