Question

Photon A has a wavelength of 200 nm and Photon B has a wavelength of 700 nm. Indicate if the following statement is about these photons is True (T) or False (F):

Photon A is moving faster than Photon B

Answer 1

The statement is False

Photons are constituents of light, photons travel at the speed of light. Photon A is not moving faster than Photon B. The reason is the speed of light (and thus photons) in vacuum does not depends on the characteristics of the light. It does not depend on its wavelength, frequency, polarization, intensity, etc. No matter that the light has wavelength of 200nm or 700nm, they both travel at the same speed in vacuum.

In some medium like water, glass, etc, the speed of the two lights could be different.