High speed and low speed photons

The animation is unfortunately misleading. The speed of light is constant and all photons, of any energy, travel at the same speed. Higher energy photons have smaller wavelengths (or, equivalently, higher frequency) but not a different speed.

Unfortunately, this is difficult to illustrate clearly. The reason the illustration shows the higher energy photons as faster is because of the naturalness of equating speed with kinetic energy of an object. It "makes sense" to most people that a more energetic particle would move faster, even if this isn't an accurate description of the phenomenon.


No. the energy of a photon is not linked with his speed. all photons move at the same speed $300.000 km/s$, that corresponds to the speed of light. The different energies of pictures are associated with frequency or wavelength of this. the greater the wavelength, lower energy and vice versa. this is: $$ E = h.\nu $$

Depending on their wavelength, electromagnetic radiation is given different names, ranging from energy gamma rays (with a wavelength of about picometers) to radio waves (wavelengths of the order of kilometers) through the visible spectrum (the wavelength is in the range of tenths of micrometer).