Physics Time Travel - Will it ever be possible?

Sep 3, 2002
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My son has an interesting theory
( not sure where he got it from some bizarre tic -tic or whatever thing he stares at incessantly , he claims it's his own )

Anyway goes like this :
More along the lines of teleportation than time travel ( same thing I guess ) but is focussed on copying the consciousness ( soul) and implanting that into a new physical body in a different time
It sounds feasible given how far technology has come in mapping /copying the brain but copying and then resurrecting the soul is hard to get your head around
Like the articles in the links below

Good luck young people !
Let me know when you've nailed it so I can go back and make the Dockers not So sh*t 🤣
Sounds like him (or whoever he saw it off) is posting the plot of Travelers.
 
Jun 14, 2015
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Maybe we can't travel back in time, but it would be nice if we could watch history on TV or something. Like a livestream right into Hitler's bunker, so we can see for sure if he shot himself or he got snuck outta there and moved to Argentina.
 
If you were able to somehow transport a telescope to a position many light years from earth, then use quantum theory based communication to instantaneously communicate the results back here, we would be rewarded with a view of earth in the past.

Unfortunately we'd be looking from so far away we wouldn't see much.

Certainly not into Hitlers bunker.
 
Jul 13, 2015
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That's the thing, isn't it? How do we know it hasn't happened at some point in the future? (A contradiction in the past/future tenses, but I couldn't think of a better way to put it).

How do we know that in the year 2849 for instance, time travel was finally perfected (there I go again) and people from that time onwards have been travelling into the past, on the basis that (a) they blend in with the locals so they aren't identified and (b) they don't interfere with events of the time?

Because millions of people would have been at the birth of Jesus and someone would have killed Hitler as a baby.
 
Jul 13, 2015
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Yeah going forwards is kind of possible in theory.

I thought going backwards violates the laws of thermodynamics / entropy?

Time travel also requires travelling through space. The Earth 2,000 years ago was in a very different place. Imagine having to allow for rotation and orbit to the centimetre over such a length of time. You could end up encased in the the Earth's crust, 18 km in the air, or miss the entire planet by 2 million km.
 

Eagle Wrath

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Does anyone want to post the math? :D
1627187646709.png
 

Eagle Wrath

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I did hear a physicist suggest that time travel would most likely only work from the moment a time travelling device is invented. In other words, you cant go back before that invention. Obv just a theory. So not sure how helpful it would be on the day its invented.
 
Oct 19, 2020
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An astronaut can do that just by orbiting the Earth for long enough so that time dilation occurs. But that doesn't count in the context of this thread. Moving objects, animals or people forwards or backwards through a substantial period of time is a completely different proposition.
 
Oct 23, 2014
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It would have to be illegal because then going backwards through time would destroy the current reality, unless it just creates a new one I guess.

That is my answer to why we don't see time travellers from the future, any time traveller would destroy their timeline or create an alternate timeline, and therefore wouldn't do it, or would have done it but a different timeline would have been created so it wouldn't occur in this one.

Going forwards through time is done all the time. Whenever you move in a direction you're travelling through space and time.
 

Rusty Brookes

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No because I don't think time exists - it's a very useful illusion that allows us to understand change. In order to measure time you need a starting point and an end point. By definition, only one of those points can exist. Neither the future or the past exists. Therefore time doesn't exist as the two criteria can't be fulfilled. Another way to think of it - how long does the present last? It can't be measured. The universe by definition is in a constant state of change. Does change have a direction?

This still works with the theory of relativity. The rate of change is relative - but that's not time travel.
 

CD Xbow

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No because I don't think time exists - it's a very useful illusion that allows us to understand change. In order to measure time you need a starting point and an end point. By definition, only one of those points can exist. Neither the future or the past exists. Therefore time doesn't exist as the two criteria can't be fulfilled. Another way to think of it - how long does the present last? It can't be measured. The universe by definition is in a constant state of change. Does change have a direction?
Yes, it's called time.
Sadly we know literally nothing about time, other than the experience of it. Even those clever physicists have no solid ideas. We know it's an essential feature of our macroscopic universe and we can measure/experience it's relentless progression but that's about it. The how, why and what of it remain unknown. The direction of change is as good description as any I have heard.
 

CliffMcTainshaw

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I've figured out half of it. I can go forwards in time quite slowly, although when contemplating how to travel back in time, travelling forwards in time seemed to happen a lot more quickly than I experienced. Although occasionally, I have noticed that I may have travelled a lot quicker forward through time than usual. Strangely it always has something to do with alcohol. I remember where I was but have no memory of how I got to my location. Instant time travel perhaps?
 
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I've figured out half of it. I can go forwards in time quite slowly, although when contemplating how to travel back in time, travelling forwards in time seemed to happen a lot more quickly than I experienced. Although occasionally, I have noticed that I may have travelled a lot quicker forward through time than usual. Strangely it always has something to do with alcohol. I remember where I was but have no memory of how I got to my location. Instant time travel perhaps?

Its not without side-effects though. Travelling forward through time seems to cause some degradation to the human body.
 
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