• Natanox@discuss.tchncs.de
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    5 months ago

    But only after 10 years. You couldn’t see anything that wasn’t visible from the viewpoint of the mirror beforehand, as from earth’s point of view the mirror isn’t there yet. And if you’re there anyway… you can just look at Earth with the craft that’s on the position of the mirror already.

    • Beacon@fedia.io
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      5 months ago

      That’s why we need to find a natural mirror somewhere already out there, so we can see into our past. Something like a planet made of pure mercury, or an arrangement of blackholes doing gravitational lensing that bends our light back to us, or whatever. We’d also need instruments vastly superior than what we currently have in order to get any useful information out of seeing our own light bounced back to us from so far away

      … But still! the idea that it’s at least hypothetically possible to actually see our own past is very exciting!

      • Klear@quokk.au
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        5 months ago

        Just look in any mirror. What you see is also you in the past.

        • Optional@lemmy.world
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          5 months ago

          “‘That’s a picture of me when I was younger.’ Yeah, no shit. Every picture of you is a picture of you when you were younger.”

          -Mitch Hedberg

          • Beacon@fedia.io
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            5 months ago

            He didn’t curse in that line. In fact he didn’t curse much generally. I don’t have any objection to curse words, it just doesn’t sound like his voice when you add curse words in.

            Fuck shit ass titties. I just had to get that out after talking about not cursing

        • Sprawl@lemmy.world
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          5 months ago

          True true. Heck it takes some 100-150ms for your brain to register what your eyes have seen.

        • Venat0r@lemmy.world
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          5 months ago

          You don’t even need a mirror, just look at your hands or feet or whatever, that’s what your hand or foot or whatever looked like 2 or 3 nanoseconds ago.

      • kernelle@lemmy.dbzer0.com
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        5 months ago

        I’m assuming the inverse square law would hinder us from seeing anything useful. But now I’m imagining scientists being ecstatic about discovering a foreign signal, only to realise its us from the past

        • MotoAsh@piefed.socialBanned
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          5 months ago

          That’s highly unlikely basically because of the inverse square law. Even tightly focused beams dissipate quite effectively over light-hours, let alone light years. We’d be lucky to catch a single photon from our past selves over any significant distance.

          For reference, look up how weak the signal is even just coming back from the moon when people try to hit the retroreflectors with lasers. Or how crazy weak the signals are when they reach Voyager.

        • Beacon@fedia.io
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          5 months ago

          it’s far easier to just look at recorded images or videos.

          You’re missing the idea of why this is cool. Recorded images only go back a couple hundred years

      • Natanox@discuss.tchncs.de
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        5 months ago

        No, the light would be reflected as soon as the mirror is set up. If the mirror is set up 10 lightyears away it would take 10 years for you to see it and whatever it reflects. There already is light on the way to the position of the mirror before you set it up.