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197 points amichail | 1 comments | | HN request time: 0.001s | source
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freeqaz ◴[] No.41864625[source]
Is there anything stopping you from putting 2+ satellites out "closer" but in the path of the lensed light, capturing the light simultaneously, and then resolving the image via async computation later? I think this is called interferometry and I know it's hard because you need _very_ precise timing, but I'm curious if that would be possible or not. (Maybe you can get the timing in sync with atomic clocks, or by sending a laser to both from a central point that lets them keep time with some very tight tolerance?)

Weird idea but I wonder if there are ways to take this from "crazy tech" to "hard tech".

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cyberax ◴[] No.41865336[source]
> Is there anything stopping you from putting 2+ satellites out "closer" but in the path of the lensed light

The Sun. Literally.

Satellites have to be that far for the Einstein ring to be bigger than the apparent size of the solar disk.

Edit: to make it a bit more clear, the gravitational lens does not quite behave like a normal lens. Instead, you see the light from _behind_ the object. So if you're too close to the lensing object so that the Einstein ring is not larger than it, you'll just see a part of the object to be a bit more bright.

Also, the gravitational lens does not actually _focus_ the image, it distorts it into a band around the lensing object.

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freeqaz ◴[] No.41867605[source]
But if the light is "warping" around the object then would you be able to grab the light from either side by intercepting it there? If you are at the X AU required for lending, but you sit at X/2 AU with some slight offset, you would be in the path of the light that would be traveling to X AU eventually.

I understand if what I'm trying to describe is impossible, I just don't fully understand why. (Is it out of focus? Is the sun too big/bright?)

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1. HellzStormer ◴[] No.41870514[source]
I'm no expert here. You mention "either side" as if the light came from both the left and the right. But I think the light would be coming along a circle all around the sun depending on exact position.

So the trick here is that if you are at the focus point, you get all that light in a small area "for free". But if you try to catch the light on the way, you now need to catch eveywhere in a whole massive circle, which is basically impossible, so you only catch a minuscule amount of the light. And then have to deal with interferometry.