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Greedy-Creme-995 t1_j5imark wrote

Theoretically it’s possible but we also already know about Earth’s past so there’s no reason to try and do something like this.

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Onlydp t1_j5imaxp wrote

Would the images even make it back and if so won’t they take a very long time?

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fransschreuder t1_j5iml0h wrote

You would have to wait millions of years for your data to come back

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Firebatx36 t1_j5in0w9 wrote

The short answer is yes. The long answer would involve data transmission times, light travel equations, and a bunch of other stuff I'm not qualified to explain past the basics.

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raselralog t1_j5infka wrote

Keep everything aside and try to digest how vast our observable universe is. Even the word theoretically gets lost somewhere. Even information gets lost. Those lights we see from distant stars 🌟 we not sure if it's still there or not. Signals from voyager take just a little over 20 light hour to reach earth. Imagine the distance.

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BarcodeNinja t1_j5io6qn wrote

If you teleported yourself with the telescope, then yes. Otherwise you would have to wait a long, long time for the data.

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Teutooni t1_j5ioc82 wrote

Could theoretically make do with powerful enough telescope here and a suitable lens far away that directs the light from earth back.

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Cannibeans t1_j5iocuq wrote

No. At 20 lightyears away, you'd need a telescope 1000x the size of the Earth for a single human to appear as a pixel, and even then you'd only be seeing 20 years into the past. This gets exponentially worse the further you go.

Millions of light-years away, there's not enough photons to collect. You'd need a telescope the size of several galaxies, made of material harvested from thousands of other galaxies, just to make out the planet.

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drdan82408a t1_j5ioz7y wrote

Sure, but there are a few problems with that.

  1. to see the earth from millions of light years away would require a telescope that is beyond the realm of imagination. The andromeda galaxy is about 2.5 million LY away, so think about resolving a single star in andromeda, and then think about resolving something much smaller in the glare of a star. But you did say a telescope strong enough, so….

  2. however many light years away you send the telescope, it will take that many years for the signal to return to earth. So if you sent the telescope to Andromeda 2.5 MLY from earth, you would get images back in 2.5 million years, of what would be then 5 million years ago.

  3. if there is intelligent life on earth in 2.5 million years; it will certainly be different than today. To give some perspective, that was when the first Homo habilis were differentiating from Australopithecus. I think it’s doubtful that our computers will be able to talk to each other when the signal arrives.

  4. similar to the problem in resolution of the telescope, keeping a radio signal coherent over that amount of space would be a heck of an engineering challenge and take a tremendous amount of energy.

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SpartanJack17 t1_j5ipf32 wrote

Hello u/Billy_bilo_, your submission "Theoretically if we could instantly send a strong-enough telescope to a location millions of lightyears away from Earth, would we be able to see into our past?" has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

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NotAHamsterAtAll t1_j5ipglb wrote

Short answer, yes.

Its not different from me making a big boom, and you standing far away. By the time you hear that noise, it was made well in the past.

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