Seeing the milky way in it's past

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In summary, the light from one of the young galactic cores we observed through the deep field image could be the milky way as it was billions of years ago, but we don't know for sure because the universe is expanding and the distance between opposite points is increasing faster than the speed of light.
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Snuka_wut
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Alright, this has been egging me for awhile now, so here it goes. If light has a finite speed, and the rate of acceleration of the expansion of the universe has sped inflation up past this finite speed, is it possible that one of the young galactic cores we observed through the deep field image is in fact the milky way as it was billions of years ago, with that light just now reaching us? And if that's possible do you think we could track, via imagery, the evolution of our galaxy?
 
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Snuka_wut said:
is it possible that one of the young galactic cores we observed through the deep field image is in fact the milky way as it was billions of years ago, with that light just now reaching us? And if that's possible do you think we could track, via imagery, the evolution of our galaxy?
No
Two reasons, since we are in the milky way we have been moving with it as space expands, so the light from it has always had the same distance to travel to us. So we have always seen the center (30,000lyr away) as it was 30,000yr before NOW for all NOW

Secondly expansion of the universe doesn't change the size of galaxies - things which are held together by gravity stay together as the universe expands.
It's like imagining a river flowing out to sea. The river flow expands out into the ocean, but a boat that is floating down the river doesn't stretch out when it reaches the ocean - it is held together by bolts/welds etc in the same way as gravity holds a galaxy together.
 
  • #3
Is this related to the analogy of the expanding universe like an inflating balloon? One possible conclusion of this is if you look far enough, you will see yourself (or your galaxy) off in the distance, the line of sight wrapping all the way around the balloon and back. I believe the answer to this is "most likely not". The expansion of the universe results in a Doppler shift so high that light emitted from one side of the universe would never get to the other side. Another way to put it is the distance between opposite points increases by at least one light year every year.

Another consequence is that if you were to take a high-relativistic spaceship out to circumnavigate the universe, at one point you would realize that you could never get to your destination and you could never return home. The universe at beyond some distance behaves though it is expanding faster then the speed of light. If the acceleration of the expansion of the universe is real, someday expansion may be so high, it will rip apart stars, atoms and subatomic particles.
 

FAQ: Seeing the milky way in it's past

Can we see the Milky Way in its past?

No, it is not possible to see the Milky Way in its past. Light from distant objects takes a long time to reach us, so we are always seeing objects as they were in the past. The light from the Milky Way that we see today is from thousands of years ago.

How far back in time can we see the Milky Way?

The farthest back in time we can see the Milky Way is about 13.2 billion years ago. This is the age of the universe, and it is when the Milky Way was first formed.

What can we learn from seeing the Milky Way in its past?

By studying the Milky Way in its past, we can learn about the evolution of our galaxy and the universe as a whole. We can also gain insight into the formation of stars, planets, and other celestial bodies.

How do we see the Milky Way in its past?

We see the Milky Way in its past by observing distant objects that are located within our galaxy. These objects, such as stars and nebulae, emit light that has traveled for thousands or millions of years before reaching us.

Is it possible to see the Milky Way in its present?

Yes, it is possible to see the Milky Way in its present. However, we can only see a small portion of our galaxy due to the vast distances between stars and other objects. Additionally, our view of the Milky Way is affected by factors such as light pollution and atmospheric conditions.

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