Spacetime question

[Fermion]

I have been reading this sci-fi book (it isn't great, but it is ok for a kindle unlimited free book).

A discussion about time and space and this scenario got me thinking about how a lot of other books and tv shows miss this problem.

Say you can travel faster than light...through warp drive or wormholes hyper space, folded space, whatever.

Ok, so you aim a telescope at a distant point, maybe one light year away. You warp,jump your way to there near instantly and shine a big laser back at your telescope and then warp back. You start gazing through the telescope and after a year, you see the flash of the laser light.

Did you not just travel through space, but back in time? From the moment you start looking at the telescope, the light takes a year to get to you so it happened a year ago.

Doesn't this mess up like every tv show, Star Trek, Dune, etc. if people are actually traveling back in time when they fold space?

 

[HawkeyeNFO]

Stay off the drugs.

 

[ejman]

I'm not understanding the travel back in time for myself part. at 8 am 1/1/22 I travel from earth one light year away and shine the laser back at earth and I instantly return back to earth where I arrive at 8 am 1/1/22. I then wait for a year and see the laser light at 8 am 1/1/23. I'm one year older when I see the laser light where/how does the time travel for me take place?

 

[Chuckanut]

No problem. The trick is to tie in subspace transmissions with gravitational waves while injecting Chrononon particles into the stream of dark matter riding the waves. EZPZ.

 

[Fermion]

I'm not understanding the travel back in time for myself part. at 8 am 1/1/22 I travel from earth one light year away and shine the laser back at earth and I instantly return back to earth where I arrive at 8 am 1/1/22. I then wait for a year and see the laser light at 8 am 1/1/23. I'm one year older when I see the laser light where/how does the time travel for me take place?

Maybe I told it wrong.

I am going to chalk it up to a) just got my 2nd dose of Shingrax and feel horrible, and b) you get what you pay for with free books.

 

[skyking1]

fiction authors take poetic license, and science fiction authors take astronomical amounts of it

 

[Out-to-Lunch]

Say you can travel faster than light.

Just stop right there. Anything else you have to say is not worth a serious discussion.

 

[FI_RElater]

No problem. The trick is to tie in subspace transmissions with gravitational waves while injecting Chrononon particles into the stream of dark matter riding the waves. EZPZ.

you missed the tachyons...

https://en.wikipedia.org/wiki/Tachyon

 

[Kork13]

Time is frame-relative. From an observer in your scenario, it would appear that the laser was initiated a year prior. However, in your frame of reference, time continued moving forward, and you saw the laser a year after you fired it.

Otherwise, I'm with Out-to-lunch ... Faster than light travel is an impossibility. Bending space-time to reduce the distance between two points in the universe (through some of the various means you mention, among others) could theoretically be possible. But you're never moving faster than light. A relative observer could perceive that you did so, but in reality you would have simply traveled at sub-light speeds, traversing a shorter distance to get there.

 

[Bullwinkle]

I remember something how if you could break the rule about moving information faster than light, then you effectively have time travel, and all the paradoxes that come with it. I don't remember the exact mechanism, but it was one of those things where if you break one fundamental physical law then everything downstream breaks, and some of those things it's hard to imagine being without, such as causality.

One movie I seem to remember did pay attention to such details was Superman. Since he could fly around the world faster than the speed of light, he wound up going back in time. You can be sure Superman won't get something like that wrong.

Also I remember in Dune the reason navigators could navigate is they used spice to see into the future. So, timey-wimey things are going on, and all is well with the physics.

 

[Car-Guy]

Spock could have answered that question. But you can read this, as a start, and then try to figure it out yourself.
https://en.wikipedia.org/wiki/Time_dilation

 

[razztazz]

I have been reading this sci-fi book (it isn't great, but it is ok for a kindle unlimited free book).

A discussion about time and space and this scenario got me thinking about how a lot of other books and tv shows miss this problem.

Say you can travel faster than light...through warp drive or wormholes hyper space, folded space, whatever.

Ok, so you aim a telescope at a distant point, maybe one light year away. You warp,jump your way to there near instantly and shine a big laser back at your telescope and then warp back. You start gazing through the telescope and after a year, you see the flash of the laser light.

Did you not just travel through space, but back in time? From the moment you start looking at the telescope, the light takes a year to get to you so it happened a year ago.

Doesn't this mess up like every tv show, Star Trek, Dune, etc. if people are actually traveling back in time when they fold space?

Exactly. It's all BS. That's why it's Science fiction. Makey-uppey. They always try to come up with a sort of deus ex machina-style explanation of how things work but it's mostly just double talk designed to sound credible. The best shows/movies/books that do the time travel thing are the one's that don't bother to explain it or just speculate. Hey, it's a mystery even to the people in the story. Shows like Star Trek are more encumbered so you just have to buy off it. I've never been a consumer of fiction though.

 

[Masquernom]

You should also consider;

Time moves slower the stronger the gravity field you are in.
Time moves slower the faster you move.

 

[USGrant1962]

Tau Zero by Poul Anderson is an interesting exploration of time dilation (not FTL). I think it was free on Kindle, but looks like no longer.

https://www.amazon.com/Tau-Zero-Pou...s=books&sprefix=tau+zero,stripbooks,61&sr=1-1

 

[sengsational]

So many things in science fiction are glossed over or unrealistic, if you stop to think about it. I always wonder why the fight between two independently developed species is always so closely matched. You'd think one would have an unexpected trick up their sleeve and blast the other into submission in the first battle. But somehow, some way, it always comes down to hand-to-hand combat

 

[Kabowest]

I foresee two possibilities. One, coming face to face with herself 30 years older would put her into shock and she'd simply pass out. Or two, the encounter could create a time paradox, the results of which could cause a chain reaction that would unravel the very fabric of the space time continuum, and destroy the entire universe! Granted, that's a worse case scenario. The destruction might in fact be very localized, limited to merely our own galaxy.

 

[Chuckanut]

So many things in science fiction are glossed over or unrealistic, if you stop to think about it. I always wonder why the fight between two independently developed species is always so closely matched. You'd think one would have an unexpected trick up their sleeve and blast the other into submission in the first battle. But somehow, some way, it always comes down to hand-to-hand combat

You might consider reading The Three Body Problem a Chinese science fiction trilogy. Earth gets a message from a planet many light years away.

We need to take your planet from you to survive. We will arrive in 400 years.

Now what happens?

I always wondered why a huge earth like planet that could easily have hundreds of millions of inhabitants or even billions, is ruled buy one old guy in one small village or town that the Earthmen managed to show up at. It would be like aliens landing in some small town in an obscure place like New Mexico and finding that the leader of Earth to lives there. Oh Wait! That happened! Sort of. Maybe that's the problem, they didn't find our Earthly leader in Roswell, got frustrated and left.

 

[Car-Guy]

Me thinks somehow Warren Buffet can see into the future. Maybe it's a little cloudy or out of focus sometimes or just quick flashes.

 

[mystang52]

Science fiction is called fiction for a reason. One has to accept the basic premise of the story or the whole story line unravels. I've seen a couple of non-fiction shows that discuss the technical feasibility of time travel (wormholes, etc.) but even then they describe other unresolvable problems, such as the grandfather paradox.
As an aside, and sort of related, some of the old Twilight Zone episodes are incredibly childish, ignoring basic science that was known even then.

 

[corn18]

By current mathematical constructs, C is absolute, constant and inviolate in all frames of reference. But that is a cop out, IMHO.

Thought paradoxes are what lead Einstein to develop the Special and General Theory of Relativity. So keep on asking these questions.

I am working on a model that tries to explain why we can't "see" 95% of the matter and energy in the universe. While the General theory and quantum crowd are off chasing unknown particles, I am thinking of a 5th dimension. Imagine what a 3D object looks like in 2D space. You can't "see" the whole object, but the impact of the 3D object that lies outside of your 2D universe could be observed. Seems like that might be what is going on in our known space-time. There are 5D things that we can't detect but have a significant effect on our 4D universe.

In addition, I am working on a thought experiment on how a thermos knows whether to keep something hot or cold. Lots of complex math with this one.

 

[sengsational]

I'm also thinking additional dimensions ... I think the math of string theory needs 11. I'm less mystified by heat conduction

 

[Fermion]

Well, if you go back to the generally excepted premise that in the big bang, everything started from essentially nothing, expanding into the giant universe we have today, then things like time travel and paradox really don't seem so far out there.

 

[Car-Guy]

I can wrap my mind around the big bang (and the concept of the big crunch) but the idea of a never ending universe "stretches" my limits.

 

[Qs Laptop]

This is my kind of discussion. I've got a lot of "what if" questions about time travel and paradoxes. Let's get started...

Let's say I'm a JFK assassination historian. I've written several academic papers, a couple of textbooks, and have been on lecture tours. A time traveler from the future goes back in time to 1963 and prevents the assassination of JFK. What happens to my life's work? What happens to my memory of JFK's death and aftermath? What about the millions (billions?) of other people with the same memories of JFK dying on November 22, 1963? What about all the history books, newspapers, news reels, etc. that recorded the assassination? >Poof< They're gone?

 

[Car-Guy]

^^^
While I'd love to know the truth about the JFK assassination, (among other things) I don't believe that time travel is possible now nor will it ever be. Other than we are always moving forward in time.. But that's me...