Physicist Trying To Send a Signal Back In Time

phil reed writes "University of Washington physicist John Cramer is attempting to send a signal back through time." From the article: "We're going to shoot an ultraviolet laser into a (special type of) crystal, and out will come two. lower-energy photons that are entangled," Cramer said. For the first phase of the experiment, to be started early next year, they will look for evidence of signaling between the entangled photons. Finding that would, by itself, represent a stunning achievement. Ultimately, the UW scientists hope to test for retrocausality — evidence of a signal sent between photons backward in time. The test will involve sending one of the photons down 10 miles of fiber optic cable, delaying it by 50 microseconds, then testing a quantum-mechanical aspect of the delayed photon. Due to quantum entanglement, the non-delayed photon would need to reflect the measurement made 50 microseconds later on the delayed photon. In order for this to happen, some kind of signal would need to be sent 50 microseconds back in time from the delayed photon to the non-delayed photon. (Confusing? Quantum physics is like that.)

Comments

I heard about this

[alnapp]

Yesterday

Re:I heard about this

[Anonymous Coward]

and it was already a dupe!

Re:I heard about this

[Anonymous Coward]

2009 called and they want their joke back.

Re:I heard about this

[igny]

The major problem of time travel is grammar. See, you have already screwed been have it up .

Re:I heard about this

[niktemadur]

A young rocket scientist named Wright
once travelled much faster than light.
He set out one day, in a relative way
and arrived on the previous night.

Re:I heard about this

[Rufty]

No, no, NO! *This* is the dupe. The original was posted next week...

Re:I heard about this

[syukton]

That might be enough pasty white skin to compensate for the melting polar caps and beneficially alter the albedo of the earth, even if only for a few hours.

I always knew that nerds would ensure the end of global warming, just not quite like this...

A HA!

[lavid]

So this is how Bif gets rich. I knew there was no Sports Almanac.

Re:I am Positive, this cant work...

[MicrosoftRepresentit]

Yes, forget any of the laws of physics that might be violated here, the primary concern is this breaks the fundamental rule of the universe, the core axiom at the heart of space and time; it would allow people to cheat at the lottery.

Re:This makes no sense

[rifter]

You mean to tell me that it only just now occurred to someone to send an entangled photon through a spool of fiber and see how it affects its twin, which took a direct path?

Also, I thought entanglement couldn't be used to transmit information, as a consequence of Somebody or Another's Law.

Can anyone clarify just what this poorly-written and sensational article is actually saying?

No, this is Slashdot. You want real physicists, and you're probably barking up the wrong tree.

However you may receive several answers. They are statistically likely not to include the right answer to your question, but rather to fall into one of the following categories (in fact you may just get all of these):

1) Someone will pretend they know what they are talking about and give you a very long and detailed answer. Unfortunately it will be horribly wrong, but only people with the proper background will realize it (ie no one here). :D

2) Someone will post a completely offtopic ad hominem attack on you for no particular reason (brain hurt! must strike thing that make brain hurt!) for bonus it will probably have something to do with your sexual proclivities and/or your mother.

3) Someone will post a completely unrelated troll hoping to get people to actually read it.

4) Someone will post a smart-aleck comment predicting the reasons you will not receive your answer (Hi there!)

5) In Soviet Russia, ??? profits you!

Dear Mr Gates...

[pandrijeczko]

640K won't be enough.

special type of crystal ?

[ei4anb]

I wonder if they are going to use resublimated thyotimoline?

Of course, in the clasical version of this experiment the crystal is usualy spherical with a diameter of about 20cm.

Re:special type of crystal ?

[OneSmartFellow]

I wonder if they are going to use resublimated thyotimoline?

Highly unlikely, the Nuntz coefficient is too high. More likely they would choose a lower Keyton class substance like floriumnated calpoproxylene.

Dear Me

[asjk]

Don't marry her.

Grammar Nazi

[jdbartlett]

If you're going to have given people grammar advice, at least have done it correctly: you're using the the present ultraconditional subinverted sem-active past subjunctive deponent aorist, so that should have been "scrodding".

Re:Grammar Nazi

[leshert]

Give him a break. He's obviously using the 2011 Revised Edition of Dr. Dan Streetmentioner's Time Traveller's Handbook of 1001 Tense Formation, back-published in 2090. The rules for deponent verbs were changed in the 2010 Third Revisionist Edition, which had willn't have beent back-publishent until 2071.

I understand that the rules for declension will have beent back-revised in the 2010 1/2 Fourth Revisionist Edition (Twice Removed), due for publication in a year that I can't yet mention, as the Unicode character set legally required by the "Second Enhanced Pan-Euro Metrification of Year Descriptors" has not yet beent post-back-ratifiedent in the current timestream. I shall have been gotting back to you sometime last week on that issue, which should clear things up a treat.

Re:Not the only scientist trying this

[LordLucless]

We'll finally have an answer to the Grandfather paradox.

Volunteers reqiured for scientific experiment to redefine time as we know it. Lack of attachment to grandparents a plus.