# Time travel could be possible ... in the future



## Whitestar (Nov 5, 2007)

Theoretical physicist Amos Ori has calculated in his equations that time travel, especially into the past could indeed be possible, but unlike previous models which require negative energy or exotic matter, this one created by Mr. Ori does not need it, thus, making time travel a seem like a real possibility. Here is the article:


*Time travel could be possible ... in the future*

By Roger Highfield, Science Editor

It may take more than a nuclear-powered De Lorean or a spinning police box, but time travel could actually be a possibility for future generations, according to an eminent professor of physics.

How the machine works
http://www.telegraph.co.uk/news....109.xml

When would the rich and famous travel to?
http://www.telegraph.co.uk/news....309.xml

Your view: Where would you go if you had a functioning time machine?
http://www.telegraph.co.uk/news....w09.xml

Prof Amos Ori has set out a theoretical model of a time machine which would allow people to travel back in time to explore the past.

The way the machine would work rests on Einstein?s theory of general relativity, a theory of gravity that shows how time can be warped by the gravitational pull of objects.

Bend time enough and you can create a loop and the possibility of temporal travel.

Prof Ori's theory, set out in the prestigious science journal Physical Review, rests on a set of mathematical equations describing hypothetical conditions that, if established, could lead to the formation of a time machine, technically known as "closed time-like curves."

In the blends of space and time, or spacetime, in his equations, time would be able to curve back on itself, so that a person travelling around the loop might be able to go further back in time with each lap.

In the past, one of the major challenges has been the alleged need for an exotic material with strange properties - what physicists call negative density - to create these time loops.

"This is no longer an issue," he told The Daily Telegraph.

"You can construct a time machine without exotic matter," he said.

It is now possible to use any material, even dust, so long as there is enough of it to bend spacetime into a loop.

Even though Prof Ori, of the Technion-Israel Institute of Technology, believes his new work strengthens the possibility of a real Tardis, he would not speculate on when a time machine would be built, or even if it would ever be possible.

"There are still some open questions."

The main remaining issue is the stability of space time, the very fabric of the cosmos, in time travel scenarios.

But overcoming this obstacle may require the next generation of theory under development, called quantum gravity, which attempts to blend general relativity with the ideas of the quantum theory, the mathematical ideas that rule the atomic world.

Time travel has long been a fascination, HG Wells grappled with the scientific issues in his 1895 science fiction classic, The Time Machine, Dr Who is still fighting the time war and Hollywood insisted all that was needed for time travel was a De Lorean and a good flash of lightning.

But more serious work on general relativity first raised the astonishing possibility of time travel in the 1940s.

In the half century since, many eminent physicists have argued against time travel because it undermines ideas of cause and effect to create paradoxes so that a time traveller could go back to kill his grandfather so that she is never born in the first place.

In 1990, the world's best known scientist, Prof Stephen Hawking proposed a "chronology protection conjecture", which flatly says the laws of physics disallow time machines.

Three years later, Prof Ori concluded that the possibility of constructing a time machine from conventional materials could not be ruled out.

Prof Hawking then fought back with his Cambridge University colleague Michael Cassidy and they concluded that time loops are extremely unlikely.

Tongue in cheek, Prof Hawking added that there is experimental evidence that time travel doesn?t exist: "We have no reliable evidence of visitors from the future. (I'm discounting the conspiracy theory that UFOs are from the future and that the government knows and is covering it up. Its record of cover-ups is not that good.)"

But now, in Physical Review, Prof Ori has provided some more advanced solutions to the problems of time travel outlined by the likes of Prof Hawking, helping to realise an idea that dates back millennia and appears in 18th century literature, Harry Potter, Dickens, sci-fi movies and much more besides.

See link: 

http://www.telegraph.co.uk/earth....108.xml

While Ori thinks that time travel into the past is possible, he does not subscribe to the parallel universe/multiple timelines like theoretical physicist David Deutsch. Ori is convinced that even though time travel into the past is possible, we can only observe it but never change it. Personally, I tend to favor the "man with no past" because the time traveler is in no danger of erasing his existence, hence the present can never be changed but the past can. It sounds weird and cool but I like that scenerio. But Ori's theory of time traveling into the past also sounds fascinating.

Thoughts anyone?


----------



## Rawled Demha (Nov 5, 2007)

interesting. so would we be invisible, unhearable, untouchable, unsmellable (?) spectres in the past then? not too disimilar from your average ghost...


----------



## Soggyfox (Nov 5, 2007)

from my vague and uneducated readings of quantum physicy stuff, isn't it unlikely you can actually travel back in time to your own time line but in effect you jump between universes to parallel universes.

isn't it something in the many universe theory....

then again i could be talking tosh, its not unheard of.


----------



## Dave (Nov 5, 2007)

Soggyfox said:


> from my vague and uneducated readings of quantum physicy stuff, isn't it unlikely you can actually travel back in time to your own time line but in effect you jump between universes to parallel universes.
> 
> isn't it something in the many universe theory....
> 
> then again i could be talking tosh, its not unheard of.


If you are going to travel back in time in a series of loops as suggested, then I'm not sure how that would work out... 

On the first loop you would travel back to a different reality; and create a new one in which you are still there because you haven't yet left. It is not the same as the reality the traveller himself experienced, otherwise he would have seen himself earlier. You create a second new reality at that point because in the future you may or may not travel back in time.

Now, if you then travel back in time a second time, and you go further back again, then you create more new realities that previously never existed. But could several time-travellers on their travels appear in the same reality?

The only thing certain is that you could never ever return home, you would always be stuck in a reality with at least one more of you.

I'm from the school of thought that if we haven't seen Time-Travellers then they are never going to exist.


----------



## Soggyfox (Nov 5, 2007)

Dave said:


> The only thing certain is that you could never ever return home, you would always be stuck in a reality with at least one more of you.
> 
> I'm from the school of thought that if we haven't seen Time-Travellers then they are never going to exist.


 
interesting traveling back in time is one thing but more important is to be able to travel forward in time. I would think the ability to decipher which reality it is you came from to be most important, given that every choice/decision made is creating an alternate reality/timeline then even making one choice in history gives you 2 timelines, mulitply that up by everything else, and my brain begins to hurt.

how would we know what the evidence would be for anyone having travelled through time? not as though you going to wear a bi badge that says, "hi I'm a time traveller, want to know the lottery numbers?"


----------



## Dave (Nov 5, 2007)

Soggyfox said:


> ...how would we know what the evidence would be for anyone having travelled through time? not as though you going to wear a bi badge that says, "hi I'm a time traveller, want to know the lottery numbers?"


Very true, but I think one might have made a mistake at some point. I expect that slip-up might become big news.

The alternative position would have to be that the world is filled with Time-Travellers, all of them keeping it a huge secret, identifying each other by a secret handshake. If I believed that, then it would be like believing in aliens and alien abductions. People would avoid me in the street and make fun of me on TV.

Actually, wouldn't this scenario make a good TV series or a maybe a Will Smith film?


----------



## GOLLUM (Nov 5, 2007)

Interesting topic, thanks for posting...


----------



## Soggyfox (Nov 5, 2007)

Dave said:


> Very true, but I think one might have made a mistake at some point. I expect that slip-up might become big news.


 
any number of incidents that we put over to luck or chance could be a time traveller using inside knowledge, Is Bill Gates a Time Traveller knowing in the future how computers/internet take off and cashing in not so very subtly. I would think if they are around they are very obvious and we pass them by as lucky people or in the right place at the right time.


----------



## Harpo (Nov 5, 2007)

Once again I reiterate my belief that a working time machine will be a machine in which a person can time-travel.  The machine itself stays put, the traveller can travel to any time during the machine's working existence.  
If someone builds the first working machine and it remains operational for 100 years, then  a traveller could use it to visit any point during that 100 years, not before or after.
Obviously what would happen is that the first machine built would become as famous as the Apollo moon landings.  As soon as the machine is switched on a traveller from the future would arrive in it, the time-travel equivalent of Neil Armstrong.

This is why we see no time-travellers around us, they'll be here in the future, just not yet.


----------



## Rawled Demha (Nov 6, 2007)

ah i see. so you cant travel in time to a place where there is no time machine. there are any number of paradoxes brewing here. 

am i right in assuming that this method would not allow travel into the future?

and also, would this time machine be a nexus for time travellers, the one stable place in a varying world? sorta like a Dark Tower?

what if there is more than one time machine? what if the time machine is damaged or destroyed? what if the time machine is moved?


----------



## Harpo (Nov 6, 2007)

Obviously, after one working machine is built, others would follow.  If later models start operating while the first machine is still active, any time-travellers could travel to the limits of one machine (yes, into the future or the past) and then switch to the other machine.  Ultimately there would be an entire network of machines throughout future history, and travellers could travel in stages far further into the future than any single machine could operate for.

If the time machine is damaged or destroyed, that's something which would be known about afterwards, and the information would be passed back and forth, it'd be common knowledge - in the same way that we all know it's not safe to visit Chernobyl.

That first arriving time-traveller would be closely followed by people bringing advanced versions of TT machines, in kit form or whatever.  Which means that within 24 hours of the first machine being switched on, there would be many other machines set up and operating, and within a few days it would be a worldwide phenomenon.
Of course there would be chaos, riots, and so on - as various beliefs are proved incorrect.  Once these problems are resolved (and the solutions would all come from the future, where such chaos and troubles are taught in their history books), time-travel would become as common as car-travel is for us today.


----------



## Harpo (Mar 14, 2014)

farntfar said:


> So let me get this right.
> Harpo came up with the theory that time travel was invented simultaneously at all moments in time some time in or around 2006, and also in 2012 and 2013.
> Foolishly, or perhaps diabolically cleverly, he published this theory, on the Chrons,which allowed Douglas Adams to read the theory several years after his own death, and send his past (and living) self a letter so that he could use it 1982 in Life the Universe and Everything.
> Thus he proved the existence of both time travel and ghost reading; (Ghost writing having been established some years earlier), and also brought the average delivery times of a GPO delivered letter down to merely one or two days, in one fell swoop.
> It only remains for a later and wilier Harpo (if such a creature could be imagined) to send a similar letter to his as yet unborn self in order to break a few more records.


 (the 'edit post' feature has been damaged in transit - please assume this edit was made in 2007, thankyou)


----------



## Aquilonian (Mar 15, 2014)

Whitestar said:


> Tongue in cheek, Prof Hawking added that... We have no reliable evidence of visitors from the future. (I'm discounting the conspiracy theory that UFOs are from the future and that the government knows and is covering it up. "



A good illustration of the fact that very clever people can still talk nonsense. 

This is like the so-called Fermi Paradox, which assumes that if aliens visited Earth they would identify themselves like in those 1950s films where they all say "take me to your Leader."

Could it not be that if a civilisation is scientifically advanced enough to create time travel and/or instellar travel, they would also need to be ethically advanced enough to have an absolute rule of non-intervention, like Prime directive in Star Trek?

This is NOT because ethical and scientific development necessarily proceed in parrallel- they clearly don't. But if a society advanced that far scientifically WITHOUT advancing ethically, they would be unlikely to avoid destroying themselves by war and/or pollution, climate change, etc, resulting from the selfish pursuit of short term material gains.

I'm inclined to beleive that very few civilisations last long enough to develop interstellar travel, let alone time travel. But if they did, we would not know anything about them. They probably wouldn't even be allowed to post on internet forums, for fear of giving us ideas!


----------



## Nick B (Mar 16, 2014)

I think the danger there Aquilonian is humanizing things that are not human. Any alien race out in the galaxy/universe/other dimensions may be so utterly different to us that things such as morality and ethics would be ridiculous to apply.  It may even be that we humans are an oddity in that we happily destroy ourselves and our environment.

What if we met an incredibly ancient race that advanced to high technology but for whom the idea of raising a weapon against their own kind simply didn't exist, it just didn't happen. 
"But how would they know how to fight?" I hear. Maybe they arose in a place where they were not alone as a sentient race and killed the others off. Maybe the race was plagued by predatory creatures. Maybe war was introduced to them by another alien race and they simply found themselves good at it.

It doesn't matter why a race may make war, or why they may not have any understandable morality or ethical code. What matters is that we don't make the mistake of thinking any alien species, or even far future versions of humanity, are anything that we can understand.


----------



## logan_run (Nov 3, 2017)

I would like to time travel one day,


----------



## Vladd67 (Nov 4, 2017)

Dave said:


> Very true, but I think one might have made a mistake at some point. I expect that slip-up might become big news.
> 
> The alternative position would have to be that the world is filled with Time-Travellers, all of them keeping it a huge secret, identifying each other by a secret handshake. If I believed that, then it would be like believing in aliens and alien abductions. People would avoid me in the street and make fun of me on TV.
> 
> Actually, wouldn't this scenario make a good TV series or a maybe a Will Smith film?


@Dave looks like you need to sue the makers of Travelers for stealing your idea


----------



## Dave (Nov 4, 2017)

Nah! I went back in time to 2007 and only wrote that after watching Travelers in 2017.


----------



## Harpo (Nov 4, 2017)

*time-travelling 2013 Harpo arrives in his time machine*
Will you lot please keep the temporal noise down?
I'm supposed to be on holiday!
*departs in machine, back to 1970*​


----------



## Mike Donoghue (Nov 4, 2017)

Nick B said:


> I think the danger there Aquilonian is humanizing things that are not human. Any alien race out in the galaxy/universe/other dimensions may be so utterly different to us that things such as morality and ethics would be ridiculous to apply.  It may even be that we humans are an oddity in that we happily destroy ourselves and our environment.
> 
> What if we met an incredibly ancient race that advanced to high technology but for whom the idea of raising a weapon against their own kind simply didn't exist, it just didn't happen.
> "But how would they know how to fight?" I hear. Maybe they arose in a place where they were not alone as a sentient race and killed the others off. Maybe the race was plagued by predatory creatures. Maybe war was introduced to them by another alien race and they simply found themselves good at it.
> ...



I posit that intelligent, technology advanced life elsewhere in the universe _will_ share many traits with us humans, let alone any toll manipulating intelligent species. For example, insects in appearance and physiology are quite "alien" to us humans, yet there are still behaviors and social structures we have commonality with: there are ants that cultivate fungus and the entire bee/wasp hive system. The common thread is _cooperation_. A species can't survive if individuals are always in direct competition, nor can any life form, by itself, rend the raw materials of its planet into an advanced civilization if it doesn't receive peaceful help from its own.

In that sense, I believe that we can look at the question of intelligent life through our biased lens. I agree with your premise that we can't assume intelligent life elsewhere will utilize violence and war like we have.


----------

