Yeah, but it’d take us strictly longer than N years to place a mirror N light years away form Earth, so kinda useless.
Space is beautiful
Submitted 14 hours ago by Stamets@lemmy.dbzer0.com to science_memes@mander.xyz
https://lemmy.dbzer0.com/pictrs/image/c6cb2d0a-4227-42c6-8644-f3cf0cb2f86e.webp
Comments
stevedice@sh.itjust.works 1 hour ago
Sprawl@lemmy.world 22 minutes ago
We just need to point our telescopes towards the phantom zone where Zod and his buddies can reflect the light back.
Natanox@discuss.tchncs.de 14 hours 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 14 hours 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
Klear@quokk.au 14 hours ago
Just look in any mirror. What you see is also you in the past.
kernelle@lemmy.dbzer0.com 10 hours 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
ameancow@lemmy.world 7 hours ago
… But still! the idea that it’s at least hypothetically possible to actually see our own past is very exciting!
We… we have tools for seeing our past. We have extensive records of imagery from as far back as we have orbital satellites. You can go on Google Earth right now and look at older maps.
I mean, I get why it would be cool to see a reflection from the past, but literally every reflection you see is from the past. At a certain distance from your reflective or distorting surface, you’re going to need major image processing to make out a clear image of the planet, so again, at that point it’s far easier to just look at recorded images or videos.
There is a much cooler idea though that you can exploit from this principle: you can use a star or other dense object in space to work like a light-lens, we could build this now but it would be a very expensive and long-term project, because we would need to send a series probes out past the distance that Voyager 1 has already traveled over 40 years. We would also need to know ahead of time what our target is so we place the probes in the right place, placing the sun between the probes and the target at just the right distance.
If you take the distorted light from around the edges of the Sun and reconstruct it, you can theoretically see details of continents and other surface features of Earth-sized planets in entire other solar systems, which would be fantastic.
bravesilvernest@lemmy.ml 14 hours ago
Hey, don’t you bring logic in here!
IrritableOcelot@beehaw.org 12 hours ago
Only after 20 years. Light will take 10y to make it from earth to the mirror, and 10y to travel back.
Natanox@discuss.tchncs.de 12 hours 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.
anothercatgirl@lemmy.blahaj.zone 10 hours ago
it takes way more than 10 years to ship a mirror from Earth to some place 10 ly away from earth.
dontsayaword@piefed.social 14 hours ago
None of these sound like deal breakers to this great idea
saltnotsugar@lemmy.world 14 hours ago
NASA: We’ve been getting a lot of footage of you being cringy in high school.
janus2@lemmy.zip 7 hours ago
oh god oh fuck there’s indestructible physical evidence of my Homestuck phase
hakunawazo@lemmy.world 5 hours ago
Dicska@lemmy.world 10 hours ago
Meh, amateurs. Being cringy as a kid at times is pretty much inevitable. That’s when you learn your ways.
You can watch me being cringy as an adult for decades.
harmbugler@piefed.social 6 hours ago
You can already do this with the light bent around black holes, it’s just a bit hard to make out the image… make sure you wipe down your black hole with a damp cloth, you don’t want a smudgey black hole
niktemadur@lemmy.world 5 hours ago
“Aw man… that’s the third goddamned cloth I’ve dropped into this goddamned event horizon this week… and it’s barely just Tuesday.”
ivanafterall@lemmy.world 5 hours ago
Redd Foxx was ahead of his time.
Kolanaki@pawb.social 8 hours ago
It’d actually be cool as fuck if we could make some kind of Payday-style time machine that lets you see into the past by simply looking at light reflected off other celestial objects.
It could theoretically work looking backwards, but not forwards as it was used in the film.
BuboScandiacus@mander.xyz 7 hours ago
Kolanaki@pawb.social 6 hours ago
lol
Real time, tho. That way we can see photographs from before cameras, too. Watch what dinosaurs were doing n stuff.
ameancow@lemmy.world 7 hours ago
Alternatively, and slightly cheaper, put a satellite into orbit and just record everything on the ground it looks at, hang onto recordings for 10 years.
InnerScientist@lemmy.world 7 hours ago
But that’s boring, doing it with light is way better.
Also the governments already do that and don’t want to share.
icelimit@lemmy.ml 6 hours ago
Wow that’s what the movie was called. It’s been on the back of my mind for years.
mybuttnolie@sopuli.xyz 11 hours ago
and if you look through the butt end of the telescope, you can see in the future
blackbrook@mander.xyz 7 hours ago
Isn’t the butt end, the end you normally look through? I’d think the end facing the stars would be the front end.
Bennyboybumberchums@lemmy.world 3 hours ago
Or youd see 20 years into the future… Let that one bake your noodle for a spell…
Sprawl@lemmy.world 20 minutes ago
No you always see into the past.
Light cannot travel back in time. The reflection you’d see in the mirror is the light that left the Earth 20 years ago.
notsosure@sh.itjust.works 14 hours ago
You may need to squint a little.
bravesilvernest@lemmy.ml 14 hours ago
It would be neat to record the mirror as it was going.
Ignoring physics of moving a mirror near the SoL, having a recording of it would both be cool to watch and would help confirm on a macro level the effects of speed-related dilation.
Lumidaub@feddit.org 13 hours ago
SoL
Satellite of Love?
ivanafterall@lemmy.world 5 hours ago
Squish of Lumbago
wewbull@feddit.uk 8 hours ago
Sound of Linguine
this@sh.itjust.works 19 minutes ago
If you did this quickly with a warp drive or whatever, you would still need at least ten years to see the results, so you could only see as far back as when you put the mirror up at the most.