The Quantum Experiment That Simulates a Time Machine

KentuckyFC writes One of the extraordinary features of quantum mechanics is that one quantum system can simulate the behaviour of another that might otherwise be difficult to create. That's exactly what a group of physicists in Australia have done in creating a quantum system that simulates a quantum time machine. Back in the early 90s, physicists showed that a quantum particle could enter a region of spacetime that loops back on itself, known as a closed timelike curve, without creating grandfather-type paradoxes in which time travellers kill their grandfathers thereby ensuring they could never have existed to travel back in time in the first place. Nobody has ever built a quantum closed time-like curve but now they don't have to. The Australian team have simulated its behaviour by allowing two entangled photons to interfere with each other in a way that recreates the behaviour of a single photon interacting with an older version of itself. The results are in perfect agreement with predictions from the 1990s--there are no grandfather-type paradoxes. Interestingly, the results are entirely compatible with relativity, suggesting that this type of experiment might be an interesting way of reconciling it with quantum mechanics.

Comments

Well, that precludes my hope.

[allaunjsilverfox2]

No Steins;Gate green bananas for me! Tuturu!

So can a flock of starlings

[Anonymous Coward]

It's amazing, that if you know the starlings are flying east to west, and you can only detect a starling as a complete *flock* of starlings, and not see the individual birds, then the flock can jump back east, i.e. back in time, interacting with the previous version of itself. Gosh!

Its like the starlings are simulating quantum mechanics!

Well either that, or we're looking at a system (starlings/photons) and its just that our mechanism for detecting them (sight/interaction with matter), means we can only see the flock and not the individual (bird/?). So the thing you know as a photon, is actually a flock of something smaller that is sufficient in density to promote an electron. If it couldn't promote the electron we could not detect it. Hence you're not seeing what you think you are, its just that you refuse to accept the divisibility of photons despite the evidence slapping you in the face.

But lets keep making those equations describing the weird time travelling/ trans-dimensional world of starling flocks. It makes for better science fiction.

Re:So can a flock of starlings

[wonkey_monkey]

Just because quantum mechanics doesn't make intuitive sense to you, doesn't mean you can come up with any old analogy and dismiss the work of people far more qualified in the field than you. Well, you can, obviously, but it doesn't make you right.

It's amazing, that if you know the starlings are flying east to west, and you can only detect a starling as a complete *flock* of starlings, and not see the individual birds, then the flock can jump back east, i.e. back in time, interacting with the previous version of itself.

How is "jumping back" analogous to "interacting with the previous version of itself"?

Gosh!

How about, instead of being condescending, you perform some experiments - or even just provide more than a half-baked analogy - to disprove the last 100 years of quantum mechanics? Obviously all the devices we've been able to create based on this hard-won understanding must be figments of our imagination...

So the thing you know as a photon, is actually a flock of something smaller that is sufficient in density to promote an electron.

Isn't that completely incompatible with the photoelectric effect? You know, the very phenomenon which lead to the concept of the photon in the first place?

Re:Various physicists

[Unixnoteunuchs]

Accounts of Dr. Gödel's contributions are often inconsistent or incomplete.