Time for the object or person in question stops. This does not affect the objects around which aren't travelling at that speed or the region of spacetime which is around them. A simple and possible explanation is that time is stopped for the photon, but this stays unnoticed because we are not moving at that speed and so we cannot say what is happening to the photon.
Massless particles traveling at the speed of light include photons, the particles of light. They have no rest mass and always move at the speed of light in a vacuum according to the theory of special relativity.
Photons ('particles' of light) have zero rest mass. When they move at the speed of light (the normal situation) they do have momentum due to the relativistic nature of the Universe. If we were to hypothesize light particles with mass the development of the Universe would be entirely different.
They can ONLY move slower than the speed of light.
Absorption of light by atoms of an element occurs when photons of light with energy levels matching the energy levels of the electrons in the atom are absorbed. This causes the electrons to move to higher energy levels, and the atom becomes excited, leading to the absorption of light.
None. At the speed of light, time stops completely. It is impossible for anything with an invariant mass to move at the speed of light; only particles with no "rest mass" (such as photons) can do so.
Yes, photons do.
Speed is how fast something moves. Light is a form of energy carried by massless photons, these photons move at the speed of light, which is the fastest speed that anything in the universe can travel.
Yes, a photon moves at the speed of light, because photons have no mass.
Massless particles traveling at the speed of light include photons, the particles of light. They have no rest mass and always move at the speed of light in a vacuum according to the theory of special relativity.
Photons, as massless particles, always move at the speed of light in vacuum and cannot be accelerated further. They can change direction or wavelength through phenomena like reflection, refraction, or scattering, but their speed remains constant at the speed of light.
No object that has mass when it's just sitting there on the table can move at the speed of light. Photons have zero "rest mass".
Yes. A neutrino usually moves CLOSE to the speed of light; this means that (unlike photons, which only move at the speed of light) it is possible to have SOME observer for which it is motionless.
An object that normally doesn't move at light speed (so, this doesn't include photons for example) CANNOT move at the speed of light. As it approaches the speed of light, its mass will get higher and higher (and tend towards infinity); as will the energy required to continue speeding it up.
No, all photons have the same mass. Photons are massless (i.e. zero). All the energy in a photon is in its momentum, but increasing its momentum does not change it speed which is always "the speed of light". All massless particles always move at the speed of light.
Lots of differences. For example: light is a flow of electrically neutral particles (called photons), that move at the speed of light (at least, in a vacuum). Electricity is a flow of charged particles - often electrons - that move at speeds below the speed of light.
No, photons neither effect time nor affect time.
Light is produced when electrons in atoms move to lower energy levels, emitting photons in the process. These photons then propagate as electromagnetic waves through space. The speed of light in a vacuum is approximately 300,000 kilometers per second.