Can we see our own galaxy out there due to gravitational effects?

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Discussion Overview

The discussion centers around the question of whether it is possible to see our own Milky Way galaxy in space due to gravitational effects, particularly through phenomena like gravitational lensing. Participants explore the implications of gravitational lensing and the nature of light from distant galaxies.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants question whether gravitational effects could allow us to see our own galaxy from a distance, considering the nature of gravitational lensing.
  • One participant asserts that gravitational lensing can create multiple images of distant galaxies but argues that there is not enough mass to bend light around to show our own galaxy.
  • There is a query about whether the duplicate galaxies observed through lensing are from the same moment in time or different moments, highlighting the complexity of light travel times.
  • Another participant expresses skepticism about the possibility of viewing a distant version of the Milky Way and questions how one would know if they were observing such a phenomenon.
  • A later post introduces the idea that light can orbit a black hole and speculates on the possibility of light traveling in reverse due to gravitational effects, likening it to the Apollo 13 mission's use of the Moon's gravity.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether it is possible to see our own galaxy due to gravitational effects. There are competing views regarding the nature of gravitational lensing and the implications for observing distant galaxies.

Contextual Notes

Participants express uncertainty regarding the conditions under which gravitational lensing occurs, the requirements for light to travel in specific paths, and the implications of light travel times on observations.

NWH
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This is a bit of a dumb question, so I apologise for the bluntness, but I was wondering. Can we see our own Milky Way out there in space due to gravitational effects? I understand that gravity allows us to view single galaxies in duplicate positions across the sky, it made me question whether we can see our own galaxy out there somewhere due to similar effects.
 
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NWH said:
This is a bit of a dumb question, so I apologise for the bluntness, but I was wondering. Can we see our own Milky Way out there in space due to gravitational effects? I understand that gravity allows us to view single galaxies in duplicate positions across the sky, it made me question whether we can see our own galaxy out there somewhere due to similar effects.

No.

You can get gravitational lensing resulting in light taking very slightly different paths over enormous distances, as it is curved by passing around a large cluster of galaxies, and this results in multiple images of other galaxies far behind the cluster. But there's not enough mass to turn light right around.

Here's a Hubble photo showing multiple images of the same galaxy.
148928main_image_feature_575_ys_4.jpg

(source; Hubble Captures A "Five-Star" Rated Gravitational Lens, NASA)
 
Yeah, I figured the answer would be blunt, thanks. So, these duplicate galaxies we're viewing, are they from precicely the same moment time? Or are we viewing the galaxies from different moments in time?

In that picture you posted, what is the body which is bending the light? Is it visible in this picture?
 
NWH said:
Yeah, I figured the answer would be blunt, thanks. So, these duplicate galaxies we're viewing, are they from precicely the same moment time? Or are we viewing the galaxies from different moments in time?

In that picture you posted, what is the body which is bending the light? Is it visible in this picture?

Images are from different times, depending on how long light took on that particular path.

To get an effect like this, you need a whole cluster of galaxies, not a single body. I think that the other galaxies you see in the image are part of that cluster.
 
How would you know if you were looking at a distant version of the MW? I seriously doubt that is possible, but, how would you know?
 
From what I have read on other forums, it is possible for light to orbit a black hole.
If this is the case, is it also possible for light to travel in the opposite direction in the same way that Apollo 13 used the Moon's gravity to return to Earth?
Of course the odds would be astronomically small of this happening, but isn't this still possible?
 

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