Why Can We See Color In A Vacuum Even Though There Are No Electrons Present?

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AlwaysLearning

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Electrons in atoms are responsible for the absorption of light.

Vacuum is the the absence of matter & no matter equals no atoms.

Light is an EM wave, therefore it can travel through a vacuum

But if no matter exists in a vacuum, then there wouldn't be any atoms. & if there are no atoms, then how can there be electrons? & if no electrons are present, then why do we see "white"
light as it travels through a vacuum?

...white IS all the colors
 


It's not clear what you're eaxactly asking for. What do mean with "see color in a vacuum"?

By the way, if free electrons are present in a vacuum, e.g. in a vacuum tube, it's usually still considered a vacuum in technical terms. But strictly speaking, a perfect vacuum doesn't contain particles.
 

AlwaysLearning said:
Electrons in atoms are responsible for the absorption of light.

Vacuum is the the absence of matter & no matter equals no atoms.

Light is an EM wave, therefore it can travel through a vacuum
Click to expand...
Agreed.

AlwaysLearning said:
...then why do we see "white"
light as it travels through a vacuum?
Click to expand...
We don't. We only see light when it hits our eyeballs, which are not a vacuum, and do absorb light.
 

Light propagates as EM waves. This means it's carried by photons that differs from electrons. Electron are not responsible of light (or EM wave) propagation.
In CRT the electron doesn't carry light. This is generated by the phosphores on the screen, when an electron hit an atom of it.

Photons can't be classified as particles in classical terms, even if they have the dual behaviour particle/wave. In particular they are massless, then when they pass through the vacuum, it still remain vacuum. However when a photon hit our retina an electrochemical reaction is triggered so an electrical stimulus is sent to our brain. Thus we can see the light propagating in the vacuum and the vacuum is not broken by the presence of photons.
 

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