Electromagnetic waves question

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Discussion Overview

The discussion revolves around the nature of electromagnetic waves, specifically focusing on the composition of different types of waves such as light, radio waves, microwaves, infrared, ultraviolet, x-rays, and gamma rays. Participants explore the concept of photons and their properties, including mass and energy, as well as the processes that produce these waves.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the composition of various electromagnetic waves, suggesting a misunderstanding about photons and their mass.
  • Another participant asserts that all electromagnetic waves, including gamma rays, are made of photons, challenging the initial claim about mass.
  • A participant explains that the type of electromagnetic wave is determined by the frequency of the photons.
  • There is a discussion about the relationship between mass and energy, with references to E = mc^2 and the implications of accelerating massless particles.
  • Participants clarify that while gamma rays are produced through processes like electron-positron annihilation, this does not imply that photons themselves are made of electrons.
  • Further elaboration is provided on how gamma radiation can also result from deexciting nuclei, releasing energy as photons.

Areas of Agreement / Disagreement

Participants express differing views on the nature of photons and their mass, with some asserting that photons are massless while others explore the implications of energy and mass in the context of electromagnetic waves. The discussion remains unresolved regarding the initial claims about the mass of photons and the composition of electromagnetic waves.

Contextual Notes

Participants reference various processes that produce electromagnetic waves, but there is no consensus on the implications of mass and energy relationships, nor on the definitions of the waves discussed.

selearemus
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based on this picture
electromagnetic_spectrum.jpg


if light is made up of little tiny massless particles called photons
what are radio waves made of?
what are microwaves made of?
what are infrared waves made of?
what are ultraviolet waves made of?
what are x-ray waves made of?
gamma rays are made of electrons and electrons have mass
so why don't photons have mass?
how can it be that only 1 type of electromagnetic waves have mass?
 
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selearemus said:
if light is made up of little tiny massless particles called photons
what are radio waves made of?
what are microwaves made of?
what are infrared waves made of?
what are ultraviolet waves made of?
what are x-ray waves made of?
gamma rays are made of electrons and electrons have mass
so why don't photons have mass?
how can it be that only 1 type of electromagnetic waves have mass?
All electromagnetic waves are made of photons. Gamma rays too. You have been misinformed.
 
Also, the type of electromagnetic wave (microwave, radiowave etc.) depends on the frequency of the photons. The type of wave is essentially defined by the frequency of the electromagnetic waves, i.e. photons.
 
Light has mass because it has energy. E = mc^2. Light has no rest mass.

As you accelerate an object it gains mass as you approach the speed of light. If you could reach the speed of light the object's mass becomes infinite (one good reason why that's impossible). If you could accelerate an object that has zero mass to begin with it would have a real quantity of mass at light speed.

Beta rays are made of electrons and positrons, gamma rays are EM.
 
Redbelly98 said:
Welcome to Physics Forums.All electromagnetic waves are made of photons. Gamma rays too. You have been misinformed.
Wikipedia**
Gamma radiation, also known as gamma rays (denoted as γ), is electromagnetic radiation of high frequency (very short wavelength). They are produced by sub-atomic particle interactions such as electron-positron annihilation, ...

so the electron-positron annihilation produces photons?
 
selearemus said:
so the electron-positron annihilation produces photons?
Yes. But that is different than saying the photons are made of electrons.

Electron-proton interactions can produce visible light photons. Yet those photons are not made of electrons and protons.
 
Wikipedia**
Gamma radiation, also known as gamma rays (denoted as γ), is electromagnetic radiation of high frequency (very short wavelength). They are produced by sub-atomic particle interactions such as electron-positron annihilation, ...

so the electron-positron annihilation produces photons?
Yup. An electron hitting a positron normally annihilates into two 511 keV-photons.

However, I think the most common reason for gamma radiation is a deexciting nucleus. When an excited nucleus deexcites the deexcitation energy is released in the form of a photon, a gamma ray.
 

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