If light particles have no mass how is it that like particles of mass they display the characteristics of particles of mass like in the gravitational lensing of light in space?

Answer 1

Light, though it travels in a straight line in a vacuum, must follow any curves in spacetime. Recall that the volume of the universe is called spacetime, and spacetime itself is distorted or "bent" by gravity. Light, though it travels in a straight line in a vacuum, will follow any gravity-induced curves in spacetime. An example might be the deformation of spacetime around a black hole, and the resultant gravitational lensing that can occur because of it.

Light particles (photons) have no rest mass. They have an equivalent mass worked out using any of several equations or combinations

m = E/c2 or E=mc2

and since E = fxh

m = fh/c 2

m = h/Lc or L=h/mc (de Broglie wavelength for light)

where m is the mass, E is the energy of the photon, c is the speed of light in a vacuum, f is the frequency, h is Plank's constant (6.626 x 10-34 joules/sec) and L is the wavelength (usually greek lambda).

Under relativity theory, it's not strictly required for photons to have mass in order to be affected by a gravitational field. Space itself is bent by gravity, and light takes the straightest possible path through bent spacetime.

Answer 2

Even though photons (light particles) have no mass, they are influenced by gravity due to the curvature of spacetime caused by massive objects. This gravitational lensing effect occurs when light bends around massive objects, leading to the distortion of distant objects' images. This phenomenon is described by Einstein's general theory of relativity and does not require photons to have mass.