Exploring Light, Heat & Space: Earth to the Moon

In summary: 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.
  • #1
binbots
170
3
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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  • #2
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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  • #3
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".
 
  • #4
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.
 
  • #5
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!
 
  • #6
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?
 
  • #7
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.
 
  • #8
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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1. What is the difference between light and heat?

Light and heat are both forms of energy, but they have different properties. Light is a type of electromagnetic radiation that can be seen by the human eye. It travels in a straight line at a constant speed and can be reflected, refracted, or absorbed. Heat, on the other hand, is a form of energy that results in the sensation of warmth. It is produced by the movement of molecules and can be transferred from one object to another.

2. How does light travel in space?

Light travels through space at a speed of approximately 186,282 miles per second. It is able to do so because space is a vacuum, meaning there is no matter to slow down or block the light. This is why we are able to see objects in space, such as stars and planets, even though they are extremely far away from us.

3. How do we know what the moon is made of?

Scientists have been able to determine the composition of the moon by studying samples brought back by the Apollo missions, as well as analyzing data collected by telescopes and spacecrafts. The moon is primarily made of rock and dust, with some areas containing higher concentrations of certain elements such as oxygen, silicon, and iron.

4. Can light and heat affect life on Earth?

Yes, light and heat are essential for life on Earth. Light is necessary for photosynthesis, the process by which plants convert sunlight into energy. This energy is then passed on to animals through the food chain. Heat is also important for regulating the Earth's climate and providing warmth for living organisms.

5. How does the moon affect the tides on Earth?

The moon's gravitational pull is responsible for the tides on Earth. The moon's gravity exerts a force on the Earth, causing the ocean waters to bulge towards the moon. As the Earth rotates, this bulge moves around the planet, creating high and low tides. The sun also plays a role in the tides, but to a lesser extent.

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