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Seraph_Unleashed OP t1_j6587gt wrote

Reply to comment by WarWonderful593 in How far out does the suns light travel into space? by Seraph_Unleashed

Yes, but does this mean obviously if there are other intelligences in space far enough away, they can see the light front the sun, but they’re seeing the sunlight as it was light years ago. Meaning they’re seeing it in the past.

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WarWonderful593 t1_j658ygt wrote

Years ago. A light year is a measure of distance, not time. As the sun is about 5 billion years old, it's first light would be 5 billion lightyears away by now. In reality, it will be further than that because the universe will have expanded considerably in that time.

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Seraph_Unleashed OP t1_j659auk wrote

Right exactly that’s that I meant to say. So 5 billion light years traveled. An alien race would see it billions of years later. The universe is expanding but into what exactly. If it is boundless and endless does that mean once it expands to a certain point will everything then fall back and collapse on it self like the Big Crunch theory?

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beef-o-lipso t1_j65c6kp wrote

>Right exactly that’s that I meant to say. So 5 billion light years traveled. An alien race would see it billions of years later.

A being with a telescope that is 5 billion light years away today (in our frame of reference) would see the sun as it was 5 billion years ago. A being 1 light year away would see is as it was 1 year ago. That's what a light year is--the distance light travels in a year. You can't see something until the photons reach your eyes. Heck, we don't even see our Sun in real time. We see our Sun as it was about 8 minutes ago!

> The universe is expanding but into what exactly.

Unknown. Current think has it the univserse doesn't expand into anything. It simply gets larger and the distance between any two points (not matter, points) get larger.

> If it is boundless and endless does that mean once it expands to a certain point will everything then fall back and collapse on it self like the Big Crunch theory?

Also unknown. In addition, I don't think there is a known mechanism by which a reversal of the expansion could happen.

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Odd_Republic5346 t1_j65m302 wrote

Isn't the sun 4.5 bn years old ? What would they see then

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beef-o-lipso t1_j65r53i wrote

4.5 bn years then. The principle stands.

Not accounting for the universe expansion, someone X light years away would see another spot in the universe as it was X years ago cause that's own long it took light to travel from there to where ever the observer is.

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Odd_Republic5346 t1_j67e2yh wrote

I know I was just wondering what was before the sun. I looked it up and it was a solar nebula

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