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wondering

(Theory) Cosmic Mirrors: looking twice as far back in time

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Hi guys,

I'll get right to the theory: The farther we look away from our point in the universe, the farther back in time we are seeing. Therefore, if we were to find something far away from us that reflects our own light, then wouldn't we see that reflected light as twice as old? In other words, by looking at reflected light, wouldn't that light had to have traveled twice as far and, therefore, display an image twice as old (twice as far back in time)?

Would love to hear what you guys think.

Cheers!

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Like the thinking. Sound plausible. Not practical. How about using gravitational lending to bend the light around several super massive black holes and return it to its point of origin?

Welcome to the forum.

Paul

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Yes, if any aliens had built a mirror, pointed such that we could see ourselves, we would be able to see an ancient earth. From a distance it might look like a pale blue dot with clouds, like today's Earth. But it would probably be dark at night time. Changes of there being such a mirror, or anything natural doing the same thing are zero, I think.

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23 hours ago, Paul73 said:

Like the thinking. Sound plausible. Not practical. How about using gravitational lending to bend the light around several super massive black holes and return it to its point of origin?

Welcome to the forum.

Paul

I know. Essentially we would have to find the perfect scenario for a cosmic mirror to exist, as well as for it to not be rotating, adjusting, etc. enough to capture images from it. Thanks for the validation. As for the idea you provide, it also sounds plausible and just as impractical... though that could change in a few hundred years, once we master manipulating super massive black holes. ;)

22 hours ago, Linda said:

Yes, if any aliens had built a mirror, pointed such that we could see ourselves, we would be able to see an ancient earth. From a distance it might look like a pale blue dot with clouds, like today's Earth. But it would probably be dark at night time. Changes of there being such a mirror, or anything natural doing the same thing are zero, I think.

I think your odds sound about right. And what I was envisioning is a mirror large enough that the reflection incorporates a big enough picture to capture more than just the Earth (like the Milky Way, for example). But what it captured isn't the point, rather it's about seeing any part of the universe at a younger age than what we can see right now, by taking advantage of the distance doubling effect of reflected light. Of course, the mirror would have to be really far away for the effect to matter.

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I hope not otherwise my mum is going to find out it was me that set the curtains alight :help:

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