The Possibility of Paradox-Free Time Travel 421
relliker writes in with word of a paper up on the ArXiv by Seth Lloyd and co-workers, exploring the possibility that "postselection" effects in non-linear quantum mechanics might allow paradox-free time travel. "Lloyd's time machine gets around [the grandfather paradox] because of the probabilistic nature of quantum mechanics: anything that this time machine allows can also happen with finite probability anyway... Another interesting feature of this machine is that it does not require any of the distortions of spacetime that traditional time machines rely on. In these, the fabric of spacetime has to be ruthlessly twisted in a way that allows the time travel to occur. ... Postselection can only occur if quantum mechanics is nonlinear, something that seems possible in theory but has never been observed in practice. All the evidence so far is that quantum mechanics is linear. In fact some theorists propose that the seemingly impossible things that postselection allows is a kind of proof that quantum mechanics must be linear."
Time Cube? (Score:5, Funny)
http://timecube.com/ [timecube.com] ... obviously.
It's the Dark Side (Score:5, Funny)
SMBC solved this dilemma last night actually (Score:2, Funny)
Re:First Post? (Score:5, Funny)
Has nobody anything snarky to say?
They are too busy trying to build postselection time machines. Expect to lose your first post status as soon as one of them succeeds.
Re:Does this mean... (Score:2, Funny)
Yes, but the keys will be postselected to be in the worst case possible.
Finite Probability (Score:4, Funny)
Now, if we can just hook in the logic circuits of a Bambleweeny 57 Sub-Meson Brain to an atomic vector plotter suspended in a strong Brownian Motion producer (say a nice hot cup of tea)...
Quantum Mech. is a Sexy but Deceptive Siren (Score:3, Funny)
Quantum mechanics is a big tease. It seems whenever it's about to give you Jetsons or Stargate technology, there's always a big fucking loophole or caveat. You can go into the past, but you can't come back and/or die; you can travel faster than light, but the universe will end before you reach your destination; you can predict the future, but will change it in the process without knowing what the change is; you can date 3-breasted aliens, but they all have penises, or whatever. (Okay, I made up the last one.)
There must be a God, because nature wouldn't find a way to tease us with so many Almost's and fuck with our minds in so many different ways that QM does.
Or maybe it's the anthropic principle keeping us from destroying the universe with time weapons?
Something odd is going on. Time for a congressional investigation.
Re:Sign me up! (Score:5, Funny)
But if I'm going BACK in time, I'm taking some aspirin, toothpaste, deodorant, and toilet paper with me. I hope the machine is big enough.
Don't forget your towel you insensitive clod!
Re:Time Cube? (Score:5, Funny)
Fact (Score:5, Funny)
wait... what ? (Score:4, Funny)
it does not require any of the distortions of spacetime that traditional time machines rely on.
Wait, did I missed the part where time machines were something traditional or common or anything like that ?
Seriously, time travel became mainstream and nobody told me ?
John Titor (Score:4, Funny)
Re:Satruday Morning Breakfast cereal Anticipated t (Score:3, Funny)
we'll always be
just apes in a tree
Re:Primer, the Movie (Score:4, Funny)
Now wouldn't this effectively get around the grandfather clause, since you have basically created a closed loop? Because unless I missed something you could alter the past while giving your future self the knowledge of what you have done, thus allowing him to do the same and closing the loop.
I'm no expert, but the idea that the universe is a sort of cosmic small claims court judge who will grudgingly let you off the hook for your liabilities if you ticked all the right boxes on form TT-8710 seems... far-fetched to me.
Re:And Back to the Future. (Score:3, Funny)
why do you all hate your grandfathers?
Re:Primer, the Movie (Score:3, Funny)