# How can a photon have momentum but not mass?

How can a photon have momentum but not mass? How can an object have momentum without mass? It can do this if it is a wave. A wave transports momentum via its waving motion and not by physically transporting an object with mass. “Momentum” is the directional property of an object in motion that describes its ability to influence another object upon impact.

How do photons exist without mass? Why do photons have no mass? In short, the special theory of relativity predicts that photons do not have mass simply because they travel at the speed of light. This is also backed up by the theory of quantum electrodynamics, which predicts that photons cannot have mass as a result of U(1) -gauge symmetry.

Can a massless object have momentum? However, momentum is the product of mass and velocity, so, by this definition, massless photons cannot have momentum.

Is it possible that photons can have momentum? Particles carry momentum as well as energy. Despite photons having no mass, there has long been evidence that EM radiation carries momentum. (Maxwell and others who studied EM waves predicted that they would carry momentum.) It is now a well-established fact that photons do have momentum.

## How can a photon have momentum but not mass? – Additional Questions

### What gives photon its momentum?

Photons have momentum, given by p=hλ, where λ is the photon wavelength. Photon energy and momentum are related by p=Ec, where E=hf=hc/λ for a photon.

### Do photons 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. It doesn’t experience distance either.

### Do photons have mass or momentum?

Light is composed of photons, so we could ask if the photon has mass. The answer is then definitely “no”: the photon is a massless particle. According to theory it has energy and momentum but no mass, and this is confirmed by experiment to within strict limits.

### Is momentum of a photon zero?

the momentum of a photon would be zero as well as its energy.

### Does phonon have momentum?

All Answers (4) “A phonon of wavector K will interact with particles such as photons, neutrons, and electrons as if it had a momentum ℏK. However, a phonon does not carry physical momentum.

### Does light have momentum?

Since light has no mass, you may be tempted to say that light has no momentum. Additionally, everyday experiences may seem to confirm that light has no momentum (sunlight does not knock over soda bottles like baseballs do). However, light does indeed carry momentum in the form of energy.

### Why is light affected by gravity if it has no mass?

If light has no mass, why is it affected by gravity? Light doesn’t speed up its acceleration, which things with mass would do, because light has a universally constant velocity.

### What is a photon made of?

A photon is a tiny particle that comprises waves of electromagnetic radiation. As shown by Maxwell, photons are just electric fields traveling through space.

### Is matter just energy?

Not much. Some fields and particles are what you would call “matter”, but which ones are matter, and which ones aren’t, depends on which definition of “matter” you are using. Meanwhile, all fields and particles can have energy; but none of them are energy.

### Are humans matter or energy?

In life, the human body comprises matter and energy. That energy is both electrical (impulses and signals) and chemical (reactions). The same can be said about plants, which are powered by photosynthesis, a process that allows them to generate energy from sunlight.

### Can matter be destroyed?

Matter makes up all visible objects in the universe, and it can be neither created nor destroyed.