
Why are people from the future not time traveling to our period? (2012) - samet
https://www.quora.com/Why-are-people-from-the-future-not-time-traveling-to-our-period/answer/Yishan-Wong?share=1
======
jerf
There's an error that people make when discussing the Fermi paradox, where
they explain how one civilization might collapse and then move to claiming
that that's why there's nobody out there. But to explain the Fermi paradox,
you must explain why _all_ civilizations collapse before colonizing the
galaxy. It's one thing to make a fashionably self-loathing claim about how
easy it is to screw up your environment... but is _every_ alien race going to
make that error? Even in their different environments? Probably not, no.

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.

~~~
hobarrera
> 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.

~~~
jerf
"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.

~~~
dTal
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".

------
ksenzee
A whole bunch of people from 2017 just descended on this 2012 post. Does that
count?

~~~
nerfhammer
The 2012 post travelled forwards in time at normal speed to reach 2017.

------
JohnJamesRambo
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.

~~~
mhurron
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?

~~~
majkinetor
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.

~~~
RugnirViking
> 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.

------
CognitiveLens
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.

~~~
AnimalMuppet
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...)

~~~
CognitiveLens
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.

------
bdavisx
Occam's Razor answer: Because time travel to the past is never invented
because it's impossible.

~~~
Terr_
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.

~~~
thefalcon
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.

~~~
Terr_
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...

~~~
basch
[http://www.imdb.com/title/tt0112167/](http://www.imdb.com/title/tt0112167/)

~~~
Terr_
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.

------
Arizhel
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.

~~~
Apocryphon
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.

~~~
Arizhel
Whoops, you're right. I was thinking about the end of Galapagos. It's been a
long time since I read those books.

------
woofyman
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?

~~~
mark-r
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.

~~~
woofyman
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.

~~~
mark-r
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.

------
the_watcher
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).

------
gchokov
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.
\--- 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..

------
ImTalking
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.

------
douche
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?

------
PaulHoule
Because closed timelike curves aren't allowed.

------
hobarrera
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.

------
turc1656
Because we're in 1985 while they are in the new 1985A where all the changes
happen.

~~~
trsohmers
Are you sure we're not in 1985A? There's a big Biff Tanen hotel right down the
street from the whitehouse...

~~~
turc1656
HAHA. That was good. Made my day. Thank you.

------
cestith
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.

------
interfixus
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.

~~~
mynameisvlad
> chronoscope

I know what you meant, but chronoscope is another name for a chronometer.

~~~
interfixus
Thank you. I honestly never knew.

------
pessimizer
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.

------
imchillyb
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.

~~~
CognitiveLens
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.

~~~
delinka
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.

------
iamleppert
We _are_ here, us people from the future (and other "planets" and spaces quite
far off)...

------
ENTP
They did, and saved Nelson Mandella from death in prison in '91! ;-)

------
hex20
I, for one, welcome our new time traveling overlords

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johansch
Yishan Wong..

Hey, I recognize that name :)

[https://en.wikipedia.org/wiki/Yishan_Wong](https://en.wikipedia.org/wiki/Yishan_Wong)

