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First images from Euclid are in

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544 points mooreds | 6 comments | 21 Oct 24 20:15 UTC | HN request time: 0.409s | source | bottom
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lefrenchy ◴[22 Oct 24 02:20 UTC] No.41910562[source]▶
It's just so crazy to me to see a galaxy 420 million light years away. That is so much time for what we're seeing to have changed. I presume life can form within that window given the right conditions, so to some degree it just feels a bit sad that the distance is so great that we can't actually see what may exist in this moment that far away
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1. vasco ◴[22 Oct 24 02:51 UTC] No.41910744[source]▶
In another way it's really cool to be able to "see the past" even if all we see is always the past. At this level it is like a super power. If only some aliens had put a mirror somewhere far so we could see ourselves too. Or multiple mirrors at different distances.

With enough mirrors and light bouncing around the size of the universe itself can be a "storage media" of the past with different photons all around carrying "how this location looked X years ago". "All" you have to do to know what happened is find the right photon to see whatever it is you want to see.

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2. steveoscaro ◴[22 Oct 24 03:02 UTC] No.41910803[source]▶
Well that sounds like a good premise for a scifi book or movie.
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3. grahamj ◴[22 Oct 24 03:13 UTC] No.41910868[source]▶
You don't need mirrors, you just need to get in front of the photons. A time machine or warp drive will do :)

Also the past is the only thing you can perceive, there effectively is no now.

4. ujikoluk ◴[22 Oct 24 05:42 UTC] No.41911511[source]▶
For prior art in this field, see:

https://github.com/yarrick/pingfs

"pingfs is a filesystem where the data is stored only in the Internet itself, as ICMP Echo packets (pings) travelling from you to remote servers and back again."

Also https://en.wikipedia.org/wiki/Delay-line_memory

Storing data as acoustic waves gave a higher capacity in practice, as propagation is slower thus fitting a larger number of symbol per time unit.

5. ConcernedCoder ◴[22 Oct 24 05:53 UTC] No.41911560[source]▶
In theory, couldn't we focus on a perfect spot near a black hole where the light has been warped 180 degrees around it... i.e. if the black hole is 100 light years away, you'd see ( with perfect zoom, of course ) a picture of the earth 200 years ago...?

I understand that we'd have to account for the movement of objects, of course, but with computers, seems like a small hurdle...

6. IngoBlechschmid ◴[22 Oct 24 06:10 UTC] No.41911636[source]▶
https://en.wikipedia.org/wiki/The_Hundred_Light-Year_Diary

By Greg Egan, so highly recommended.