Why Can't You See Light Between the Earth and the Sun from the Moon?

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Discussion Overview

The discussion revolves around the question of why light is not visible between the Earth and the Sun when viewed from the Moon, as well as the nature of light and heat in the vacuum of space. Participants explore concepts related to the propagation of light, its interaction with matter, and the perception of light by the human eye.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that light is characteristic of a source and that it does not scatter back to the observer on the Moon due to the absence of intervening matter.
  • Others argue that light cannot "heat" empty space, as there is nothing to absorb or interact with it, although background radiation exists.
  • A participant questions how photons can enter the eye if they are not directed towards it, suggesting that observation may be more about the interaction of light with matter rather than light traveling to the observer.
  • Some participants express curiosity about the nature of light, questioning whether it behaves as a particle or a wave and how this affects visibility from distant sources.
  • There is a discussion about the spread of light particles and whether this affects the visibility of stars, with some noting that light does spread out but remains detectable.
  • One participant differentiates between light waves and other types of waves, suggesting that the wave property of light may manifest differently.

Areas of Agreement / Disagreement

Participants express a range of views on the nature of light and its visibility, with no consensus reached on the underlying principles or explanations. The discussion remains unresolved regarding the specifics of how light interacts with the observer and the implications of its wave or particle nature.

Contextual Notes

Limitations include assumptions about the behavior of light in a vacuum, the role of matter in scattering light, and the definitions of light as a particle or wave. These factors contribute to the complexity of the discussion.

binbots
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If you were on the moon looking at the earth, why can you not see light between the Earth and the sun? Same goes for heat. Why is the space between the sun and the Earth so cold. Does light and heat only exist once it interacts with something else?
If light is a particle wouldn't the particles spread out to the point where you would have no idea what of where an object is. If light is a wave wouldn't we see sunlight cover everytinhg in every direction?
 
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Interesting question. If light was shining through a volume of space with no identifiable source, thus causing you to not be able to see anything...that would be kind of funny. It could be because light is characteristic of a source. At the moment, I think the only thing we know that light interacts with other than itself (in a sense) is matter.
 
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There is nothing to scatter the light back at you. Think of light rays. The light rays that go towards Earth only hit Earth. They don't want to come to you on the Moon.

You can't "heat" empty space. There is nothing to "heat". There can be background radiation, like the CMBR, but that's only about 3K. The only reason we get to see the CMBR everywhere is that the big bang happened "everywhere".
 
Matterwave said:
There is nothing to scatter the light back at you. Think of light rays. The light rays that go towards Earth only hit Earth. They don't want to come to you on the Moon.

Yes, that is the point I am trying to make. How can Photons enter the eye from light that is not directed towards it. If a laser beam is shot across and infront of you it's photons do not travel towards you eye.

Why do we think that light always have to travel. Can in not travel and also be contained, like a sun. Not all light travels to your eye. Rather our observation travels to the light. Hard to explain, sorry.
 
binbots said:
Yes, that is the point I am trying to make. How can Photons enter the eye from light that is not directed towards it.
They can't. Your eye can only detect photons that hit it and since photons travel in a straight line...
If a laser beam is shot across and infront of you it's photons do not travel towards you eye.
Correct - unless they hit something and scatter toward you.
Why do we think that light always have to travel. Can in not travel and also be contained, like a sun. Not all light travels to your eye. Rather our observation travels to the light. Hard to explain, sorry.
That doesn't make sense...which is probably why it is wrong!
 
I am still curious how light travels from a distant star to our eyes. If light was a particle wouldn't the particles be spread out to much by the time it reached us? if it was a wave wouldn't we see a wall of light and not be able to tell where the star is? Wouldnt it be like seeing a wave from the shore, you would not be able to tell where the wave originated?
 
binbots said:
If light was a particle wouldn't the particles be spread out to much by the time it reached us?

It does. That's why stars are dim, and that's why you can see them anywhere - the light ahs spread out. But not too much to see.
 
Only those photons or waves reach our eye that are exactly in a line to the star (or almost a line due to refraction). But even then they need to be focused by our eye in order to see the star sharply. Also, I'm not sure the light waves are the same as sea waves or sound waves (circular or spherical waves). I think the wave property manifests itself as a fluctuation of force. I'm not a professor though, hopefully one of them will care to help you out.
 
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