Quantum boffins send data ACROSS TIME AND SPACE

Re: Agh, my poor brain

I don't think it's really a theory, merely a useful mathematical construct - to TREAT anti-particles as regular particles travelling backwards in time is nice for the maths solutions but that's all.

Re: Agh, my poor brain

Not to mention that quasars are already known to be active galactic nuclei. The central black hole "eating" matter, causing relativistic jets to form.

The theories expressed by AC were back from the 1960's and 1970's, before spin, color, etc were fully understood and galactic cores were mysterious objects and black holes were unknown.

Re: Fear not the paradox is, paradoxically, not going to happen.

"So the dodgy time-traveller has actually irreversibly left his original timeline/causailty-stream and created a new alternate one by his own actions in which he's now trapped, i.e. he can't 'undo' his own time travel to revert to where he used to be as he can only go back further into the parent of his timeline, creating further splices which may or may not work out more like the original one he left behind."

The Trousers of Time have a hole in them.

Worse still are the holes in the pockets of the Trousers of Time.

Re: Fear not the paradox is, paradoxically, not going to happen.

That would mean that to create a time 'spur' you'd need to recreate the mass/energy of the universe less your mass/energy for it to exist with you added to it. Otherwise your 'spur' would just collapse/fail as it would be an incomplete universe.

Proper time travel relies on either all time existing at the same time or the ability to create new universes at will at different time points, the latter might be doable if you don't mind waiting 14 billion years for your new universe to arrive at the required point in history.

Re: Fear not the paradox is, paradoxically, not going to happen.

Considering the argument suggesting multiple universes exist having been created from a branch point where a choice to do or not do occurs, then it could be argued, the meddling has already happened.

The "Mossad scientist" has actually travelled back to the branch point and continued on the alternate path, his future alone has deviated, yet he still exists in our branch as the scientist who didn't meddle.

I like to think, reality as we experience it, is the one which takes humanity on the longest journey, with the most favourable outcome, as all the other branches, if followed, result in a premature or even inconclusive end.

In other words, our reality is the product of a quantum state that transcends time, in so much as it chooses the most favourable line to follow based on the outcome of every branching event along it,

So, don't panic, God has the road map and we're not driving, we only think we are.

..and as for time travel, I would like to point your attention to the many events in out history, that are documented as being attended by only a handful of witnesses and not the millions, that would surely have turned up if the ability to travel in time was ever possible.

Re: Fear not the paradox is, paradoxically, not going to happen.

I tend to believe that there is only one timeline regardless of the existence, or not as the case may be, of time travellers. There is, in other words, only one reality.

If time travel does exist, and the traveller manages to change something "historical", will we even notice it? Our history will change, but we will believe that this is the way it has always been. The only person who will know, with certainty, will be the time traveller who changed the timeline.

Re: Fear not the paradox is, paradoxically, not going to happen.

Stop! This way lies rump of skunk and madness.

Re: Fear not the paradox is, paradoxically, not going to happen.

"I think time paradoxes don't exist - they're just a sci-fi idea... cos, if every decision, even down to the quantum level, creates a new alternate reality then...."

Personally I follow the idea of fixed time rather than whole spawned universes every millisecond.

Time is like a movie. You might figure out how to fast forward and rewind but that doesn't change the movie.

Ok imagine you go back in time to kill your father. That would create a paradox. Now with fixed time, any attempt to create a paradox would fail. You get hit by a bus before you can kill him. You go back too far in time and get eaten by a T-Rex etc etc.

Just like the past, the future has already happened and it's only the fact that we don't know what will happen that maintains the illusion of free will...

Re: Fear not the paradox is, paradoxically, not going to happen.

Itzhak Bars (http://en.wikipedia.org/wiki/Itzhak_Bars) has some interesting ideas on two dimensional Time that might be applicable.

Nicho

Is the link between 1 to 4 not a possibility though? Just because we have 2 possible options, 1) 4 effects 1 and 2) 1 effects 4 but only recently a theory for 1) with no theory for 2) does not mean 2 is "wrong" until shown so experimentally.

Don't mix theory with experimental data. The data here could show either theory correct, or perhaps both are correct?

The worse argument possible is "oh but what alternative do YOU suggest then". As it fails to show the strength of the original theory, in a false appeal to the "ridiculousness" of thinking about alternatives. If we took that attitude, we'd never have hit QM in the first place... "What alternative to classical mechanics would you suggest, the double slit experiment MUST be classical..." would get us no where. We had to use the data to shape our theory.

Teaching others about such subjects involves showing how the data fits the theory. We can all "imagine" alternatives, that is rather an inexhaustible pursuit, but only 1 will match the experimental evidence. :)

But isn't there a link between P1 and P4 via the entanglement of P2 to P3 which was entangled with P4?

Re: Neither... Its a proof...Genius or Brainfart?

Yes, at the least they need to (I hope they do in the paper, does not seem to be here in the article) demonstrate the state of particle 4 is not "set" and is QM "undetermined".

Re: Paul

I know, just thought it would be interesting in light of the questionable interpretations put forth, seems like the more likely explanation is not a surprise and the more suspect one is a ruse to get media attention. Hope that sheds some photons on this matter.

Re: Help me, Obi Wan Quantobi!

from the abstract only I would guess that the authors may have trouble publishing this paper in a real journal due to lack of novelty

Is Physical Review Letters not a "real journal", then, in your estimation? Last I looked, it was a fairly prestigious, peer-reviewed organ.

I must say I am impressed with the level of boffinry on display on the comments page today, with many confident declarations that there is nothing to see here. Time for a shakeup at the PRL editorial board? Will the Nobel committee be asking the Reg for contact information? Only time will tell (or perhaps it already has).

Re: Help me, Obi Wan Quantobi!

How do you know the characteristics are not set? You can't know that for certain because you haven't measured them yet. All this entanglement stuff only makes sense if the characteristics of the pair of photons are actually set at the moment they are created: this way Einstein needn't get upset because there is no spooky action occurring; it's just us reading the state of one, from which we can deduce the state of the other.

IANAPhysicist but I can spot a fallacy when I see one.