That’s kind of the wrong question. I’m not exactly sure how to ask because I don’t know where I’m confused.
This morning, sitting under the stars for 2 hours before sunrise, I pondered the old light of stars.I had never thought about the journey light had to travel and retain its form. I don’t understand how we see the source as a pin prick of light from that distance… and someone standing right next to you (or half way across the earth) would see the same pin prick but it would be different photons hitting their retinas.
How does the light spread like that but retain any form? If photons move perceptibly (to our measuring equipment) in close distances in the double slit experiment, how do they stay in a tight enough formation over those vast distances to still look like a pin prick when they reach us. I’m not sure I’m asking the right question but I found my mind a little boggled by what is probably a simple to explain phenomenon that shouldn’t even be confusing. Probably a couple questions in there.
Thanks!
In: 11
The light from a star expands in a sphere, We see it as a point source because its angular size in the sky is smaller than the details our eyes can resolve. The light isn’t exactly in formation, it’s just going everywhere, but it’s all coming from the same place.
The reason is you have a lens in front of your retina that focuses the light. All light that comes from one direction will be focused from the same point.
If your eye did not have a lens light from the star would hit all of it just like light from any other object. Start are not special they are just very far away from light sources.
Take a paper out in sunlight and you see all of it getting illuminated. I you have a lens that can focus the light on the paper the sun will just be a small but bright area that might deliver enough energy to ignite the paper.
Here is an example of it being done with binoculars [https://www.youtube.com/watch?v=fCnZlH4-6Go](https://www.youtube.com/watch?v=fCnZlH4-6Go) your eye do the same thing.
Draw two dots on a page. One represents a star and the other your eyeball. Now draw a bunch of straight lines radiating out from the star representing light beams, including one going straight towards your eye. The only beam you can see is the one that reaches your eye and that come from exactly the direction of the star. So you see the star in only one location, making it a tiny dot. For it to seem blurry (assuming your good vision) some light would have to come from a slightly different direction.
The stars will be blurry if you focus your eyes on something close up. This has to do with the lens in your eye, size of your pupil size of your eyeball. For your eyes, things far away are all pretty much the same; if you look at the horizon, you are using the same “setting” as when you look at the stars; at that point, all light is effectively coming in as parallel rays, 1 mile, 100 miles or 100 light years away. Different lenses and cameras have different depth-ranges that they can focus on properly. Google Depth of Field for more info
That distant sun spreads photons out in a sphere. BUT those photons are soooo tightly packed, a single stream of an extremely small portion of those photons will travel thousands of light years until it hits your eye.
A different portion hits your other eye or your neighbor.
For this sphere of photons to travel in parallel beams (rays, stream, spike, other words) and continually hit your eye or a telescope means those electrons must be very very close together. Otherwise the beam would have spread out to invisible or flickering because your eye would be ‘between’ those photon beams from so far away.
Stars flicker on earth due to atmosphere shifting, in space it is a constant pin prick.
That distant sun spreads photons out in a sphere. BUT those photons are soooo tightly packed, a single stream of an extremely small portion of those photons will travel thousands of light years until it hits your eye.
A different portion hits your other eye or your neighbor.
For this sphere of photons to travel in parallel beams (rays, stream, spike, other words) and continually hit your eye or a telescope means those electrons must be very very close together. Otherwise the beam would have spread out to invisible or flickering because your eye would be ‘between’ those photon beams from so far away.
Stars flicker on earth due to atmosphere shifting, in space it is a constant pin prick.
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