Do Photons Have Mass?

Thread starter zuz
Start date Jan 6, 2019
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Mass Photon

In summary, a photon is a fundamental particle that makes up light and other forms of electromagnetic radiation. It has properties of both a particle and a wave and is considered a massless particle because it travels at the speed of light and has no rest mass. Scientists have determined this through experiments such as measuring the deflection of light by gravity and studying their behavior in particle accelerators. Although a photon has no mass, it does have energy from its momentum and frequency. This allows it to be affected by gravity and can also affect other objects, as seen in gravitational lensing.

Jan 6, 2019

zuz

Does a photon have mass?

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Jan 6, 2019

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1. Does a photon have mass?

According to the theory of relativity, photons are considered to be massless particles. This means that they do not have any rest mass. However, they do have energy and momentum, which can be thought of as a kind of "effective mass".

2. How can a particle have energy and momentum but no mass?

This is a fundamental property of photons, which are considered to be particles of light. They travel at the speed of light, which means they have no rest mass. However, they do have energy and momentum due to their electromagnetic nature.

3. Why is it important to understand the mass of a photon?

Understanding the mass of a photon is crucial in many areas of physics, including quantum mechanics and cosmology. It helps us understand the behavior of light and its interactions with matter, as well as the structure and evolution of the universe.

4. Can a photon have a variable mass?

No, a photon does not have a variable mass. Its mass is always zero, regardless of its energy or frequency. This is a fundamental property of photons and is a key concept in the theory of relativity.

5. How is the mass of a photon related to its wavelength and frequency?

The mass of a photon is not directly related to its wavelength and frequency. However, the energy of a photon is directly proportional to its frequency and inversely proportional to its wavelength. This energy can be thought of as a kind of "effective mass" for the photon.