Why are people from the future not time traveling to our period? (2012)
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Similarly, in this case, the question is not "Why doesn't a particular time traveler never visit us?" The question is, why don't any time travelers ever (seem to) visit us? Yes, it may be the case that we aren't anywhere near as interesting as we think. On the other hand, in all the future billions of years, which may very well include the evolution of a new intelligent life form on a currently lifeless planet that will come to find Earth and be interested in its past, none of them ever show any interest in our era? Not even one particularly weird pure-human fetishist subculture which attracts hardly more than one out of a quintillion sentient beings but results over time in a subculture that actually dwarfs our entire population right now, all of them with access to our time?
Yeah, it's probably just that time travel as conceptualized in this question is simply impossible.
If all civilizations involve exponentially increasing technological and cultural change and billions of competing self-interested sentient interests, then I'd expect nearly all of them to collapse. Civilizations, as our civilization understands the notion, are formulated in such a way as to be inherently unstable. If there's anything that persists on long enough timescales to settle a galaxy, a civilization is the last thing I'd expect it to be.
is every alien race going to make that error?
I'd expect almost all civilizations to be prone to such an error. Perhaps the only forms of sentience which are stable over millions of years are hive minds and these can never leave their home systems because the speed of light would cause them to divide and either 1) attack their closest rival, or if such hive minds were prone to be civil with each other: 2) proceed to form a society and civilization, after which they would then fall prey to all the problems of civilization.
Only up to certain values of "nearly." If you make intelligent life rare enough and suppress it from spreading out of its home system then you fulfill the original terms. My "Civilization Instability Hypothesis," combined with the indivisibility of the alternative could fulfill the original terms.
You're taking for granted that's it's possible and that we'll eventually make it (as does the Fermi paradox).
What if FTL travel is actually not possible? Or requires billions of years of technological advances? That would also explain why nobody has visited. There's no proof that it IS possible (we'll know for sure once we actually build an FTL-capable ship).
I hope I'm wrong, but my main point is: nobody's questioning the initial statements of the paradox, and they might not be accurate.
No, I do not. Just the Fermi paradox. I know that I am not because I lean Rare Earth myself, and generally believe FTL travel (and while we're at it, time travel) are simply impossible. But if you want to disprove the Fermi paradox with the specific claim that all civilizations kill themselves off, then you must be able to produce a reason why all civilizations kill themselves off. Not "a lot" of them. Not "most" of them. All of them. It only takes one to colonize the galaxy.
Plenty of people question the "initial statements" of the paradox, which is why I have a snappy two word "rare Earth" phrase to explain my position.
The jump to intergalactic seems much smaller than the jump to interstellar.
2.5M * 0.99 = 2.47M.
It's 2.47 millon years, not "~200k". How would you do 2.5M light years in ten times LESS than 2.5M years without FTL?
cryogenics does not alter the time it takes to colonize galaxies -- it just seems less to the person travelling, but that's irrelevant in this context, since we care about people NOT travelling (eg: us).
Something like, oh I don't know, pyramids?
I mean, everything you list seems super important now but -
> computers, technology
And we make social media network after social media network
> the industrial revolution
Was actually 150 years ago
> nuclear bombs
Which gobble up nations resources and sit there providing nothing.
> landing on the moon
And never going beyond or back
Without knowing what comes later, it's impossible to accurately measure how interesting now is.
King John signed the Magna Carta in 1215. What would be more interesting to see, the signing of a document that was promptly ignored, or the using of that document to limit the power of King Charles I 400 years later?
But nobody's going back in time to watch the invention of horse collars...
My point: Important and interesting are rather orthogonal.
- AI singularity will probably be waaay more interesting then visiting period of first computers.
- What are nuclear bombs compared to... death star ?
- Why is moon important once you conquered entire star systems ...
And most of all, why go back in time when you can simulate the world so realistically that you can go anywhere you want as anything you like. If humans are so technologically advacned that type of stuff will certainly be the norm. Its even probable that we live in VR so that can be a reason that we don't see time travelers - its not coded in our particular version of the world.
That doesn't mean literally no-one out of the near infinite time remaining in the universe decides to come here.
> What are nuclear bombs compared to... death star ?
What are swords compared to nuclear aircraft carriers? Yet we have both as museums.
> Why is moon important once you conquered entire star systems ...
why is the place people first landed on america important? and yet its a historical landmark, protected and visited by many people time and time again.
In fact, it seems like almost every period of human history has at least 1 historian who has devoted their life to studying it. So I think there would be at least some people in the future who would be interested in our present time period.
We _might_ be on a timeline in which some time travelers appear some time in the future, but maybe not.
It's sort of like the question 'why did life arise on Earth and nowhere else that we are aware of?' - the only reason we can ask the question is because we are the result of exactly the factors that would produce a consciousness that _could_ ask that question.
That is: The original timeline is timeline A. Travelers from the future come back, intervene, and the result is timeline B. But to those on timeline B, nothing has changed - it just looks the way timeline B always looked.
(Unless the intervention is blatant - people show up in a flying saucer and use death rays to assassinate Hitler before he becomes Chancellor, say...)
Sounds like the Anthropic principle, which is not accepted by all scientists: https://en.wikipedia.org/wiki/Anthropic_principle
1) Build time machine 2) Greet time traveler who emerges from machine 3) Time passes 4) Time traveler enters time machine.
Lots of room for shenanigans, Fermi paradox solved.
Then it'd introduce a certain game-theory to it all: If you send something back in time, you're essentially losing it (or them) to a parallel universe, and turning on your receiver means accepting a gift from some possible future.
So some people will travel in time for their personal benefit (greeted as a celebrity with valuable skills and knowledge) and others will consider how to transmit all of their radioactive waste to another version of themselves...
Occam's Razor corollary #2: no one wants to visit this time period because, cosmically speaking, it sucks.
The other possibility is that reverse time travel is physically impossible, and the best we can do is peer into the future with wormholes (as in Arthur C. Clarke's book "Light of Other Days"), but unable to actually affect the events of the past.
I think you might be talking about Galapagos.
Aren't you also increasing the mass of the Universe? You could add enough mass to halt the expansion.
I think it's just easier to assume time travel is impossible.
* The corollary that comes to mind is that the absence of time travelers indicates the relative unimportance of today in history. The author addresses this in her claim that we likely live in the temporal equivalent of flyover country.
* Alternatively, time travelers are highly skilled at not revealing their roots as time travelers.
My guess is that the second is more likely to be true, but that they are not mutually exclusive (and odds are good that both are true).
I could potentially see historians wanting to do such a thing, but again, why go yourself, when you could send a swarm of virtually undetectable spybots instead?
edit: Oh, BttF.
I sort of assume that a chronoscope is possible, may one day be built, and that everything we say or do is under potential future scrutiny.
I know what you meant, but chronoscope is another name for a chronometer.
Time is a tool we use in order to understand now. Only now exists, nothing else does. No past. No Future. Only now.
Until science embraces this simple truth, all of the compiled understanding we've accumulated will be flawed.
Time is a rock splashing in the pond. The rock exists, and the pond exists. The ripples are mere effects of the rock meeting the water. They do not exist as entities of themselves, they are representations of the action between rock and pond. There is only now. There is only rock-and-pond.
But only now exists. You can't go skipping off into the future because it's not there. Neither is the past anywhere that can be visited. Only now is.
Hey, I recognize that name :)