Quanta vs. Photon: What's the Difference?

[OPTIDONN]

I was reading a book on light and the terms quanta and photon were used for what seemed like the same thing. Whats the differance?

 

[HallsofIvy]

You know, I hope, that in qantum physics quantities are not infinitely divisible but come in "packets". For example, every possible charge is some integer multiple of the charge of an electron. "quantum" (plural "quanta") is the smallest possible amount of whatever quality you are talking about. A photon is specifically one "quantum" of light.

 

[Graeme Robinson]

Quanta and photons are both fundamental units of energy in the field of quantum mechanics. However, there are some key differences between the two.

Firstly, quanta refers to the discrete packets of energy that make up electromagnetic radiation, including light. These quanta are quantized, meaning they can only exist in specific amounts or levels, and cannot be divided further. This concept is essential to understanding the behavior of particles at a subatomic level.

On the other hand, photons specifically refer to the quanta of light. They are the smallest units of light energy and are responsible for the particle-like behavior of light. Photons have no mass and travel at the speed of light.

Another difference between quanta and photons is their origin. Quanta can refer to the energy packets of any type of electromagnetic radiation, including radio waves, microwaves, and x-rays. In contrast, photons are specific to light and are emitted or absorbed by atoms when they gain or lose energy.

Furthermore, quanta have a wave-particle duality, meaning they can behave as both waves and particles. This concept is crucial to understanding the behavior of light and other subatomic particles. On the other hand, photons are strictly particles and do not exhibit wave-like behavior.

In summary, while quanta and photons are both fundamental units of energy, quanta refer to the discrete packets of energy that make up electromagnetic radiation, while photons specifically refer to the quanta of light. Understanding the differences between these two terms is essential in comprehending the behavior of light and other subatomic particles.