# Quick Answer: Do Photons Have Mass?

## Do all the photons have same mass if not why?

Although photons don’t have mass, they do have momentum because they are moving (fast!).

The higher a light wave’s frequency is, the more momentum it has and the more energy it carries, just as larger masses equal higher energies.

Gamma rays have higher frequencies than radio waves, so they have higher energies..

## How can a photon have no 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 gravity exist without mass?

The only way to get gravity is with mass. The more mass, the more gravity you get. Without mass, you can’t have gravity.

## Does matter have mass?

Matter is all the “stuff” that exists in the universe. It has both mass and volume. Mass measures the amount of matter in a substance or an object. The basic SI unit for mass is the kilogram (kg).

## Do phonons have mass?

A phonon — a particle-like unit of vibration that can describe sound at very small scales — has a very slight negative mass, and that means sound waves travel upward ever so slightly, said Rafael Krichevsky, a graduate student in physics at Columbia University.

## Do photons have gravitational mass?

Unlike particles of matter, however, photons have no mass. It is surprising, then, to find that gravity—traditionally understood as the force attracting any two objects with mass—can affect light. … It is also possible to create “artificial gravity” that affects light.

## Why photon rest mass is zero?

The rest mass is the mass of a particle (in our case the photon) as measured by an observer who sees the particle still and with zero speed. … But according to special relativity, light ALWAYS travels with the light speed c, and is NEVER at rest. And so it has zero REST mass.

## Does time exist for a photon?

Photons do not experience time. … From the perspective of a photon, there is no such thing as time. It’s emitted, and might exist for hundreds of trillions of years, but for the photon, there’s zero time elapsed between when it’s emitted and when it’s absorbed again.

## Do photons weigh anything?

Photons are the smallest measure of light, and no, they don’t have mass. … Light is composed of photons, which have no mass, so therefore light has no mass and can’t weigh anything.

## How does gravity affect light if it has no mass?

It might be surprising to you to hear that gravity can affect light even though light has no mass. If gravity obeyed Newton’s law of universal gravitation, then gravity would indeed have no effect on light. … However, when gravity is very strong, the bending of light’s path becomes significant.

## What is the mass of a photon?

According to electromagnetic theory, the rest mass of photon in free space is zero and also photon has non-zero rest mass, as well as wavelength-dependent. The very recent experiment revealed its non-zero value as 10 – 54 kg ( 5.610 × 10 – 25 MeV c – 2 ) .