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I am trying to understand how light works and electromagnetic radiation, from what I understand charges cause disturbances in electric fields, which triggers a magnetic field, and then the back and forth continues as the oscillation in both fields travel from point A to B.

What I am unable to understand is how is this connected to light, how does the frequency or wavelength of these waves allow us to see.

I also don't understand how any of this is connected to photons, and energy travelling as the electromagnetic wave.

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Light is an electromagnetic radiation of wavelength between 400-700 nanometers, you can work out the frequency via the formula $\lambda=c/f$ where $\lambda$ is the wavelength, $f$ the frequency and $c$ the speed of light in vacuum. How we see is really a question of biology, basically some particles in your eye are excited by electromagnetic waves of these wavelengths.

However, all of this is in the classical theory of electrodynamics. For a more precise description of electromagnetic interactions one needs to go to the quantum theory of electrodynamics, and treat these waves as photons.

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  • $\begingroup$ ahh, so light being electromagnetic radiation and photons is kind of two different theories. And again these disturbances in fields trigger reactions in the retina to let us see. Thats pretty cool. But I still don't see how all of electromagnetic radiation connects to energy $\endgroup$
    – Ranvir Choudhary
    Commented Jun 2 at 11:11
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    $\begingroup$ @RanvirChoudhary It takes energy to produce the waves, so by conservation of energy, that energy needs to go somewhere - precisely into the wave. $\endgroup$
    – paulina
    Commented Jun 2 at 11:19
  • $\begingroup$ @paulina But i still dont get how energy "travels" from A to B, its not made of anything, so I'm having some trouble understand how the "energy goes into the wave" and travels $\endgroup$
    – Ranvir Choudhary
    Commented Jun 2 at 11:28
  • $\begingroup$ The wave consists of photons, each of which carries energy related to its wavelength by $E = hc/\lambda$ where $h$ is Planck's constant, $c$ is the speed of light in vacuum, and $\lambda$ is the wavelength of the photon. So if you want to look at it that way, it's not the energy itself that travels, but it is being carried by photons. $\endgroup$
    – paulina
    Commented Jun 2 at 11:50
  • $\begingroup$ @paulina so does that mean the photons are carried by the oscillations of the electromagnetic field? kind of like a charge would be influenced by disturbances in an electric field? $\endgroup$
    – Ranvir Choudhary
    Commented Jun 2 at 16:09

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