Why are people from the future not time traveling to our period? (2012)(quora.com)
quora.com
Why are people from the future not time traveling to our period? (2012)
https://www.quora.com/Why-are-people-from-the-future-not-time-traveling-to-our-period/answer/Yishan-Wong?share=1
78 comments
to explain the Fermi paradox, you must explain why all civilizations collapse before colonizing the galaxy.
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.
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.
Per my other reply, if you accept the original terms of the Fermi paradox, which is that there should be a lot of alien civilizations, then merely killing off "nearly all" of them is insufficient. It only takes one species to colonize the galaxy. Life is probably nearly impossible, but it only takes one cell to colonize a planet.
Per my other reply, if you accept the original terms of the Fermi paradox, which is that there should be a lot of alien civilizations, then merely killing off "nearly all" of them is insufficient
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.
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 must explain why all civilizations collapse before colonizing the galaxy.
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.
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.
"You're taking for granted that's it's possible and that we'll eventually make it (as does the Fermi paradox)."
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.
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.
Remind me how we know the galaxy hasn't been colonized? For all we know the aliens just take one look at Earth and go "ew, not that one - it's all moldy".
Colonizing the galaxy does not require FTL travel.
Probably not, but colonizing other galaxies without it is extremely complex. The closest one is 2.5M ly away, so it'd be over 2.5M years just to get there.
If you could get to .99c then the onboard travel time would "only" be ~200k years. Something like cryogenics and it could effectively be 0 years.
The jump to intergalactic seems much smaller than the jump to interstellar.
The jump to intergalactic seems much smaller than the jump to interstellar.
Dude, not sure what sort of math you dud:
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).
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).
Relativistic time dilation. It will take 2.5 million years to an outside observer, but ~200k to those on board.
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Also if they visited any of the esrlier interesting periods on Earth they would have left some evidence behind.
Something like, oh I don't know, pyramids?
Something like, oh I don't know, pyramids?
Maybe Donald Trump is the sick joke of a time traveller.
A whole bunch of people from 2017 just descended on this 2012 post. Does that count?
The 2012 post travelled forwards in time at normal speed to reach 2017.
That's a kind of time travel as well, thanks for pointing that out.
I disagree with the notion that our time period would not be considered special to people from the future. Our recent history is the birth of the modern human- computers, technology, the industrial revolution, nuclear bombs, landing on the moon. I think it would be a time travel historian vacation hotspot.
Doesn't that depend on what comes next. This period might really be a serious lull in time.
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?
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?
I read a book called "King David's Spaceship" by, IIRC, Niven and Pournelle. It had one point in it that horse collars were a critical technology. Without horse collars, a horse could do five times as much work as a slave. A horse also ate five times as much. But with horse collars, a horse could do ten times as much work as a slave, but still only eat five times as much. This made slavery uneconomic, which changed all of society.
But nobody's going back in time to watch the invention of horse collars...
My point: Important and interesting are rather orthogonal.
But nobody's going back in time to watch the invention of horse collars...
My point: Important and interesting are rather orthogonal.
Also,
- 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.
- 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.
> AI singularity will probably be waaay more interesting then visiting period of first computers.
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.
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.
And I'm sure bronze casting seemed pretty important at the time that developed but hardly anyone thinks anything about it now save for some scientists. Our computers and internet seem pretty revolutionary now but when viewed from the future they'll probably just be another minor technological improvement.
I'm sure there are many historians who would jump at the chance to go back in time and observe ancient bronze casting first-hand.
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.
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.
I have no doubt there would be some people very interested, I'm saying that most people probably won't give us a second thought.
And, being historians, they would want to avoid making any history-altering changes, so if they do everything correctly, we'd never know they were here.
Yes, it's safe to say than in the last ~50 centuries, the 20th was quite a standout one and the 21st quite possibly will be as well.
If you go with the pop-sci idea that intervening in the past changes the future, then we are just on the timeline in which time travel never occurred in our recorded past, by definition. It's not that people from the future _don't_ time travel to our period, it's that each time they do travel to our period, a timeline branches off that we don't have access to.
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.
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.
How would you know if we are on a timeline where intervention from the future has changed the past? In our timeline, it hasn't changed.
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...)
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...)
yeah I'm thinking about it in the way that is assumed by the original author, with the idea that visitors from the future would be somehow identifiable.
We could as well be the result of a series of pranks perpetrated from time travelers from other saner timelines.
> 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.
Sounds like the Anthropic principle, which is not accepted by all scientists: https://en.wikipedia.org/wiki/Anthropic_principle
Sounds like the Anthropic principle, which is not accepted by all scientists: https://en.wikipedia.org/wiki/Anthropic_principle
It's the weak Anthropic principle - we find ourselves on a planet that supports life because we couldn't have arisen on a planet that didn't - which is necessarily true.
It is necessarily true, but it does not explain anything.
Occam's Razor answer: Because time travel to the past is never invented because it's impossible.
A somewhat more-fanciful version: Travel into the past is possible, but requires some precondition (e.g. construction of a compatible receiving-unit) which limits the range of travel to periods in which time-travel technology exists.
This is indeed my pet Sci-fi novel take on things.
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.
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.
You could also throw a multiverse-situation on top, where activating the receiver (which instantaneously captures a pending traveler) is actually what causes a branching.
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...
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...
Not exactly, thought, since you have to "opt in" to receive an, uh... Secret Schrodinger present, and it arrives at a local time and destination of your choosing. And if nothing comes, that implies all the time travelers that ever will will try traveling "past" you have already done so, implying that the end of the universe is surprisingly near.
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Occam's Razor corollary: If it is possible, they are under a Star-Trek-like prime directive not to tell us they are from the future or change anything.
Occam's Razor corollary #2: no one wants to visit this time period because, cosmically speaking, it sucks.
Occam's Razor corollary #2: no one wants to visit this time period because, cosmically speaking, it sucks.
Occam's Razor corollary: Time Travel is only permissible into the future due to entropy.
The answer is simple: time-travel technology is never developed, because human society implodes within a few decades and humans go extinct, or at best, revert to a more primitive existence and then evolution makes them progressively less intelligent (Kurt Vonnegut wrote a book about this, I think it was "Player Piano"). Personally, I think human society will look much like "The Walking Dead" within 10 years.
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.
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.
That's not what Player Piano was about at all. Player Piano, his first novel, was actually a remarkably prescient story about a future dealing with the crisis of total mechanical automation, except with the utopian-in-retrospect idea that postwar America would continue its New Deal-meets-General Electric policies so that the biggest problem for people with low socioeconomic status who lose out from automation is societal alienation and loss of the dignity of work, rather than the actual reality of increasing wage peonage and poverty.
I think you might be talking about Galapagos.
I think you might be talking about Galapagos.
Whoops, you're right. I was thinking about the end of Galapagos. It's been a long time since I read those books.
I agree. Every major human civilizations in history that has arisen has eventually collapsed, usually due to resource exhaustion. It's arrogant to think that ours won't. It's just going to be on a much much bigger, global scale this time. It will take ~200 years from now to bring the average surface temperature of the earth up to a boiling point.
I'm willing to bet we won't be like The Walking Dead in 10 years.
If you traveled back in time, the earth would had
moved on, not to mention the solar system and galaxy. Wouldn't you have to travel in time and space?
That brings the question, what would be the spatial reference point for your time machine? Until we figure out what the universal reference point is, there's no way to know where in space your time travel machine would land. You'd also need to somehow match the angle and speed of the place you're landing, or find yourself instantly flying off the Earth's surface or squashing against it like a bug.
Good points, this is getting complicated.
Aren't you also increasing the mass of the Universe? You could add enough mass to halt the expansion.
Aren't you also increasing the mass of the Universe? You could add enough mass to halt the expansion.
That's a very good point as well. You probably couldn't move enough matter to make a noticeable difference to the Universe as a whole, but it does point to a violation of some kind of equilibrium.
I think it's just easier to assume time travel is impossible.
I think it's just easier to assume time travel is impossible.
I bet that the universal reference point will be at a different location for each person who "views" it, and that it changes in between "views" for the same person.
There are two thoughts I had while reading this very thoughtful (and entertaining) answer:
* 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).
* 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).
TL;TR:
So the likely reason that time travelers from the future aren't visiting our period is (other than time travel perhaps being physically impossible) that we're just not that interesting, and we're not really that large. It's only temporal-centric egotism that makes us believe otherwise.
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Interesting answer nonetheless. Reminds me of numerous scams of people traveling from the future, including faking of very old photographs with people wearing modern Prada glasses..
I suggest that they visit all the time. The first thing a truly intelligent species would do is discard the physical form since it's inefficient and it decays over time. Think of the movie 'Lucy' where, at the end, she discards the body and just disappears. This could be the answer to the Fermi paradox since a civilisation would get to the point where this is possible and would basically disappear from the universe. Once the 'being' is part of the fabric of the universe then they could do anything and could 'exist' right in front of our noses.
In a society technically advanced enough for time travel to be a reality, I would expect that the StarTrek holodeck or some other incredibly immersive VR system is already widely available. Why go through the hassle and potential danger of actually going back in time to experience another era, when you could just dial it up and have a safe and tailor-made experience?
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?
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?
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Because closed timelike curves aren't allowed.
Why would you want to do that? You can see the past from the future. For example, grab a super-powerful telescope, move 100 light-years from earth, and you can see 1907. For a sufficiently advanced humanity, the past is totally visible, no need to travel to it.
Because we're in 1985 while they are in the new 1985A where all the changes happen.
Perhaps technology advanced enough to travel through space and time instantaneously is more importantly used to cover vast distances in space instantly than vast units of time to a more or less circular orbit of a single planet.
Physical transportation backwards in time may well be forever impossible or simply irrelevant.
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 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.
> chronoscope
I know what you meant, but chronoscope is another name for a chronometer.
I know what you meant, but chronoscope is another name for a chronometer.
Thank you. I honestly never knew.
Because there's no such thing as time, it's just a fudge to account for cause and effect. Its best definition is a circular one, the function of the distance travelled.
Time is not a universal component, it is a measurement.
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.
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.
There can be no action/reaction without time. If there is no past and no future, there is no cause and effect, so everything is either pre-ordained (odd) or it just 'is' in a completely trivial sense.
The past is a collection of "nows" that did exist. The future is a collection of "nows" that will exist. But this now is the only one that exists. Recording and remembering the past ("nows" that did exist, but no longer do) helps us predict the future ("nows" which do no yet exist, but will.) Energy cannot move across distance instantly, so we have the concept of "time" to allow us to remember where the energy started and predict where it will go.
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.
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.
Just because now is a reaction to the past doesn't mean that the way it is was inevitable. Whether you believe in free will or fundamental randomness, absolute determinism is untenable.
We are here, us people from the future (and other "planets" and spaces quite far off)...
They did, and saved Nelson Mandella from death in prison in '91! ;-)
I, for one, welcome our new time traveling overlords
Yishan Wong..
Hey, I recognize that name :)
https://en.wikipedia.org/wiki/Yishan_Wong
Hey, I recognize that name :)
https://en.wikipedia.org/wiki/Yishan_Wong
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.