Time Travel

[Alien 13]

We already know that time travel into the future is relatively easy and has already been done, all you need is to go fast or use suspended animation.  I do however wonder if there is an option for going back in time, are there any theory's even off the wall ones that would allow this or do I stick to my experiments with the hyper dimensional resonator.....

Alan

[andrew s]

Just look further away and you will see further back in time! ?‍♂️

Regards Andrew 

[JamesF]

Around here they don't put distances on signposts.  Just how many years you'll have gone back in time when you get there.

James

[m1dlj]

Surely, if it were possible, someone would have come back and told us by now.

Ray

 

[Stu]

40 minutes ago, m1dlj said:

Surely, if it were possible, someone would have come back and told us by now.

Ray

 

Even if they did, I suspect they would be locked in an institution now so we would be none the wiser

[Ouroboros]

Perhaps the many universes theory allows for time travel into the past without resulting in various forbidden paradoxes. It just wouldn't be travel back to our past, just a parallel past. 

[Alien 13]

53 minutes ago, m1dlj said:

Surely, if it were possible, someone would have come back and told us by now.

Ray

 

I do wonder if information can be sent back like changes to our DNA that includes information that we cant read till we have advanced enough or other clues hidden at the sub atomic level?

Alan

[Ouroboros]

6 minutes ago, Alien 13 said:

I do wonder if information can be sent back like changes to our DNA that includes information that we cant read till we have advanced enough or other clues hidden at the sub atomic level?

Alan

I can't see how that gets around the time paradox.  Change the past in even the slightest (even invisible) degree will change the future from that point on. 

[George Jones]

17 hours ago, Alien 13 said:

I do however wonder if there is an option for going back in time, are there any theory's even off the wall ones that would allow this or do I stick to my experiments with the hyper dimensional resonator.....

 

1 hour ago, m1dlj said:

Surely, if it were possible, someone would have come back and told us by now.

 

General relativity does not seem to prohibit time-loops (called closed timelike curves by physicists), but quantum theory might prohibit these, This is what Stephen Hawking thought.

Stephen Hawking: "It seems that there is a Chronology Protection Agency which prevents the appearance of closed timelike curves and so makes the universe safe for historians."

This roughly states that near the boundary in spacetime where time-loops form, the energy for quantum fields blow up (e.g., infinite blueshift), thus preventing (by wall-of-fire barriers) physical objects from crossing into the region where there are time-loops. There seems to be some semi-classical (part classical, part quantum) evidence for this conjecture, but a more refined analysis by Kay, Radzikowski, and Wald muddies the picture a bit. Their analysis shows that the energy is ill-defined, but not necessarily infinite, at such a boundary.

This may be just an indication that the semi-classical theory breaks down at chronology horizons, and that full quantum gravity is needed for definitive predictions.

[ollypenrice]

Me:         'I went back in time and the first thing I did was shoot Adolf Hitler!'

My wife:  'Who?'

 

Olly

[david_taurus83]

One of my favourite paradoxes is the Star Trek one! Is that an example of a closed timeline curve?

[david_taurus83]

There are 2 Star Trek ones in fact!

[George Jones]

22 minutes ago, david_taurus83 said:

There are 2 Star Trek ones in fact!

 

I can remember four episodes in (the original) Star Trek that involved travel into the past, three into Earth's past, and one into the past of another planet.

[Skipper Billy]

21 hours ago, Alien 13 said:

We already know that time travel into the future is relatively easy and has already been done, all you need is to go fast or use suspended animation.  I do however wonder if there is an option for going back in time, are there any theory's even off the wall ones that would allow this or do I stick to my experiments with the hyper dimensional resonator.....

Oh for goodness sake - I thought all this was cleared up back in 2047.  ?

[david_taurus83]

28 minutes ago, George Jones said:

 

I can remember four episodes in (the original) Star Trek that involved travel into the past, three into Earth's past, and one into the past of another planet.

Yes, there are likely more. 2 of the films stick in my mind. The 'whale' one where Scotty gives a modern engineer the formula to transparent aluminium. When Bones warns Scotty about altering history and Scotty replies, What if hes the one who invented it?! 

 

Brilliant!!

 

The other one I'm thinking of is one of the Picard movies where the Borg travel back in time to earth and try and stop Zefram Cochrane, the inventor of human warp capability, from making his first flight and eventual contact with the Vulcans. He succeeds with the help of Riker and Geordi who accompany him on his maiden voyage. Though Cochrane already had the idea and technology available prior to the Enterprise crew arriving, the question remains, would he have succeeded without intervention and on time to have his warp signature detected by a passing Vulcan ship?!

[Kev M]

You cant go back in time as it could break causality .

In the example above if the Borg had succeeded to stop " first contact".

Then "first contact" would not have happened.

Then they would not have needed to go back to stop "first contact".

Then "first contact" would have happened....

Time travel backwards becomes nonsense...what if you killed your younger self ?

Not going to happen.....

[steppenwolf]

I will shortly be publishing the full answer to the question of time travel on my website, however, if you are from the future, just check it out now.

[Kev M]

I read it tomorrow

 

[wimvb]

On 01/05/2019 at 22:48, steppenwolf said:

I will shortly be publishing the full answer to the question of time travel on my website, however, if you are from the future, just check it out now

I've read it. It'll be hilarious.

Edited May 3, 2019 by wimvb

[ollypenrice]

On 01/05/2019 at 22:32, Kev M said:

You cant go back in time as it could break causality .

In the example above if the Borg had succeeded to stop " first contact".

Then "first contact" would not have happened.

Then they would not have needed to go back to stop "first contact".

Then "first contact" would have happened....

Time travel backwards becomes nonsense...what if you killed your younger self ?

Not going to happen.....

We really do like causality, don't we? Dang, if we lost causality we'd take another hit to our egos. Copernicus was bad enough then Harlow Shapely made it even worse. For a moment it looked as if that nice Edwin Hubble had put us back in the middle of the action but then Einstein knocked that one on the head.

But maybe, just maybe, there is no such thing as causality...

?lly

[andrew s]

4 minutes ago, ollypenrice said:

We really do like causality, don't we? Dang, if we lost causality we'd take another hit to our egos. Copernicus was bad enough then Harlow Shapely made it even worse. For a moment it looked as if that nice Edwin Hubble had put us back in the middle of the action but then Einstein knocked that one on the head.

But maybe, just maybe, there is no such thing as causality...

?lly

Without some form of causality then almost nothing would make any sense. Prediction would be impossible. Retrodiction undecidable.

Now where is that nice cup of tea for my improbability drive.

Regards Andrew 

[bingevader]

On 30/04/2019 at 22:55, andrew s said:

Just look further away and you will see further back in time! ?‍♂️

Regards Andrew 

As very amateur astronomers (speaking for myself, clearly), we are in the business of historical time travel.

In 2014 I watched the supernova in M82 that happened 11.5 million years ago!

[Mr Spock]

I am from 300 years in the future. Unfortunately, my time machine won't be invented for another 300 years, so, I'm stuck here...

[ollypenrice]

9 hours ago, andrew s said:

Without some form of causality then almost nothing would make any sense. Prediction would be impossible. Retrodiction undecidable.

Now where is that nice cup of tea for my improbability drive.

Regards Andrew 

So, being strictly playful here...

Almost nothing would make any sense to us. (Nature shrugs its shoulders.)

Prediction would be unnecessary.

You never know, causality might be like epicycles, necessary to rectify gaps in our understanding. I'm not saying I like the idea...

Olly

[andrew s]

Equally playful @ollypenrice.

Causality is the basis fo all order. There could be no nature for us to fail to grasp. 

It would all be engulfed in an bicycle of paradox and contradictions.

A race to simultaneous order and disorder 

The entropy and the agony of being (or possibly not)

Regards Andrew