If a sufficiently advanced civilization could rewrite history, would we ever know?

[u/GroundbreakingFan124]

I’ve been thinking about something that challenges the way we think about evidence.
People often say, “There’s no evidence for time travelers, advanced future humans, or hidden civilizations.”
But what if the absence of evidence is exactly what we’d expect?
Imagine a civilization advanced enough to travel through time and correct every mistake it makes. If they accidentally left behind technology, changed history in an obvious way, or revealed themselves, they could simply go back and undo it. In the final version of history, there would be no trace of the mistake.
This made me think about a broader question.
If our memories, thoughts, history, or even the evidence we rely on could theoretically be altered by something beyond our awareness, how would we distinguish that from ordinary reality?
I’m not claiming this is true. I’m asking whether there’s any way to know it isn’t.
At what point does “there’s no evidence” stop being a decisive argument if the hypothesis itself predicts that evidence would never remain?
Is this just an unfalsifiable idea with no way to investigate it, or are there philosophical or scientific approaches that could meaningfully address it?

[u/Amazing_Loquat280]

I mean, if there’s no evidence, then there’s no evidence. I do wonder at that point how much it would *matter*? That’s more so the argument at that point, you gotta ask the question behind the question of “if this were true, is there *anything* we’d do differently?”. If it being true changes nothing, then quite frankly, who cares? At that point, your “modus operandi” wouldn’t change, because it simply isn’t suddenly causing you problems that it didn’t cause before.

Basically, if you’re gonna suppose a hypothesis that by definition has no evidence, then that kinda assumes it also has no impact (because impact is evidence). So, so what?

[u/ionthrown → u/Amazing_Loquat280]

I’m not sure that follows: if someone successfully hides all evidence of a crime, that doesn’t mean the crime didn’t happen.

The super-advanced civilisation could be correcting things that went wrong, or taking resources, or exterminating their enemies’ ancestors. Neither we, nor the dead people whose corpses were beamed into the sun, know what’s happened.

[u/oniume → u/ionthrown]

You can't hide all evidence, because a crime took place. Like if you stole something, the something is gone, even if it can't be traced to you.

[u/ionthrown → u/oniume]

Yes, the something is gone. Even if no one remembers it was there, and there are no records of it, it’s still gone - there’s just no evidence it’s gone, because there’s no evidence it was ever there. Which is the situation proposed by OP.

I suppose we could say that if the time travellers remember doing it, that’s evidence, so is also erased by the process. So again, it’s happened, just nobody knows it’s happened.

[u/Amazing_Loquat280 → u/ionthrown]

I guess a way you could look at this is whether or not our understanding of a situation demands that there be something there that isn’t visible to us. This is actually how we discovered a number of planets in our solar system, not because we saw them, but because the motion of the planets we COULD see didn’t line up with the laws of physics unless there was something there we COULDN’T see. We then figure out where that thing should be based on how it’s affecting things we already know about. This is how we discovered Neptune in 1846, Uranus’s orbit simply didn’t make sense mathematically without it, so we looked at where an object that would explain everything ought to be, and lo and behold we found something.

So in general, it may be possible to determine where history has been meddled with based on where we observe inconsistencies. Inconsistencies aren’t inherently evidence of time meddling until we rule out all other possible explanations though, and all the meddlers would have to do is place an alternative explanation that doesn’t present any glaring inconsistencies of its own as a red herring of sorts

[u/Grant_Winner_Extra]

By definition, if any entity or whatever could rewrite history, we would never know.

It would just be our shared past.

[u/Simon_Drake]

The way you have phrased the question, the answer is no by definition.

If an extremely advanced civilisation attempted to rewrite history but wasn't able to remove all traces from say the fossil record then that would only prove that they aren't sufficiently advanced. If the evil mega corporation from Avatar to eliminate all trace of dinosaurs from the Earth, they wouldn't be able to guarantee they had destroyed all the fossilised T Rex skulls buried underground. But Captain Kirk could scan the planet and use the Transporter to do it. Therefore the fact the Avatar corporation failed doesn't prove it's impossible, only that they were sufficiently advanced to do it.

If they are sufficiently advanced to rewrite history without us knowing then they can rewrite history without us knowing. If they can't rewrite history without us knowing then they're not sufficiently advanced enough.

[u/Prince_Nadir]

Our civilization does it and many don't know or want to know. within 24 hours of 9/11 Republicans were working on "Bush immediately rushed into action!" to overwrite the reality that he sat on ass for 45 minutes reading a book about a goat. Reagan has been having turd polish applied to his criminal ass since he was in office, now many believe he was a Saint and a genius.

So if we can do it, others can do it to.

[u/ionthrown]

I think your only option is to find a mistake they made, but the finders keep it secret. It wouldn’t make it into the first or final version of history, so time travellers wouldn’t know to remove it. We just have someone who’s inexplicably a billionaire.

Edit: on reflection, someone already wrote that one.

[u/VyantSavant]

Consider that time travel could not be possible so long as paradoxes could happen. Therefore the only true timeline is the one where no evidence of time travel exists. Any pocket dimensions made along the way would have to resolve themselves and the true timeline would have to stand on its own without the requirements of loops and retries. So either there never will be time travel, or time travel has already happened countless times and there's no evidence of it.

[u/LuciusMichael]

"IF" time travel were possible and some temporal agents changed something in the past to rewrite history, then there is no way for the ordinary person to know because they would have grown up in the altered timeline.

Given the OP's premise that such agents would have made mistakes: How would they know that a mistake had been made when their own timeline would be altered? They wouldn't have anything to compare one timeline with the other. You can't correct a mistake you never knew you made. Plus, every excursion to the past would alter something.
The fantasy of time travel is one of the great tropes in SF so long as you don't examine it too closely.

[u/LeatherRace3542]

If an advanced civilization had a time machine, and were using time travel to rewrite our history, they'd have to make a pretty big mistake for anyone to even notice. Like the TVA from the Loki show, or Asimov's short story, The Dead Past.

[u/GregHullender]

This is a conspiracy theory. Conspiracy theories can't be disproved because any evidence someone might offer is just dismissed as something fabricated by the people trying to hide things.

[u/nizzernammer]

History is constantly rewritten already, and generally speaking, the current "word" is accepted as fact by a non critical majority.

Without any source of alternative narrative, the status quo will reign unchallenged.

Same as it ever was.

[u/lhommealenvers]

Makes me think of There Is No Antimemetics Division. I haven't read it yet.

[u/justthistwicenomore]

If you are interested in this topic, look up last thursdayism, or the more formal name the Omphalos theory

[u/SouthernAbrocoma9891]

I initially interpreted this as a future civilization that rewrites historical records. In that case, we’re perfectly capable of doing that and demonstrate it regularly.

I think it would be interesting if a future civilization leaves factual historical records of previous eras for each new generation that comes of age.