It doesn't actually demonstrate any new properties of entanglement, but it's cool anyhow: a group of Austrian physicists have produced a video showing entanglement in real time. Yep, what Einstein called “spooky action at a distance” is now on YouTube (below). It took a fair amount of work for the scientists from the University …
No seriously, fuckin' eh! You wouldn't fuck with a guy like that, would you?
I like the 1920s silent film backing music in particular.
being spooked by magnetism when I was a kid. That was action at a distance I just couldn't get my head around. I understand magnetism now, quantum entanglement takes a whole new level of understanding.
Unless our concept of causality and the 2nd law of thermodynamics is all wrong, something unseen or invisible must be interacting with the 2nd entangled photon causing that photon to change quantum state in harmony with the manipulation of the 1st.
If this action at a distance took place a the speed of light there might well be classical explanation for it but we are talking instantaneous action at a distance and since nothing in the visible universe can travel faster than c.... I think we have a lot to learn about the structure of reality.
Our senses evolved perfectly for surviving in our environment The sensitivity of all our senses is very limited in that we only see a very tiny part of the electromagnetic spectrum, we can't see the curvature of space. We can understand the effects of these "invisible" features of the Universe by measuring what we deduce are the right things.(light spectra, the motions of planets, etc.). We have wondered well beyond the box that our evolved physical senses placed us in. Just as we have escaped the limits of our senses, common sense maybe the next barrier we have to surpass.... The closer one looks the more weird it all gets.
Failings aside as a species we have done and will continue to do brilliant and amazing things with reality... Providing we keep our imaginations entangled with it.
Re: I remember
>...nothing in the visible universe can travel faster than c.......
Whenever I see this expression I think, "well, of course, that's the constraint of calling it the 'visible' universe. We use light to see, and light travels at c, see?"
Re: I remember
"Unless our concept of causality..."
Nail: meet hammer. Whether the theoretical possibility of "time travel" (CTCs) or entanglement, there are tantalising hints that the universe is less wed to causality than us. Aesthetically I find Cramer's Transactional Interpretation appealing. But even if that's wrong, I don't expect our final theory of everything to be fully causal.
If only we could use this phenomenon to achieve instantaneous (faster than c) communication... it would change the world in ways I can't even imagine.
Re: if only
Technically that is exactly what it is...
It would be a better experiment if the did not use the 'A' beam as the trigger, but instead split the 'B' beam to be both trigger and detector. This way the control filter (input) on 'A' beam is remote to the measured 'B' beam (output) and could be further away.. not requiring the electrical trigger link between the two.
Re: if only
You read too much into the experiment. The spooky action is only revealed when you compare the results for the two entangled photons (using boring slower-than-c methods). There is no faster-than light transfer of information. If this fundamental tenet of physics is withdrawn, you won't read about it here, but you'll probably have learned about it in school from the future physics teacher sent back from the 24th century.
Re: if only
So if I give you an entangled particle, and alter my particle based on a bitstream. you record the changes in your particle, then bring them back and we compair, What will the results be? Will your observations become part of the waveform, only be collapsed when we compair?
If that's the case, why can I not send you the signal via the entangled particle, then send if via "slow" light. Your actions are then part of the waveform which is collapsed when the signal confirming what I send arrives. In effect, you take both actions and we just destroy the universe where you took the "wrong" action...
The problem with your concept lies in the statement " if I [...] alter my particle based on a bitstream". You can't do that. You can measure a property of your particle (and thus collapse an entangled property of my particle) -- but you can not deterministically alter you particle. (Some 'weak' statistical effects might appear in particular experiments, due to the Bell inequality.)
The experiment shown here uses one of the entangled particles to trigger the detection of the other. Because they choose to detect only selected particles with a particular property in arm one (a certain polarization state) to trigger the detection in arm 2, they choose to only observe particular particles with funny entangled properties in their second experimental arm. Hence the funny looking pictures. The important detail is the following: they must transmit information about which particle they chose to observe in arm 1 via standard (slower than light) communication. This problem always exists, hence information transfer is always limited to slower-than light. (As far as we know -- maybe magic will start to work tomorrow :)
If we're going to have faster than light communication, I'll have to learn to type faster!
Can i be the first
to say that, i didn't understand any of what i just watched. Can i also just say though, that despite not understanding it, i'm fascinated by it and its ilk.....
**Coincedence my arse, that lots been designed by a far more advanced intelligence than us....
We are mere rats in a lab....
FTL comms NOT
Bernard d'Espagnat, a recognized physicist demonstrated that even though something can happen at faster than light speed, it is not possible to transmit any information through that process. I can't explain the details, but what he did wasn't a conjecture or an hypothesis but a real scientific demonstration (I guess according to current knowledge, of course...)
I believe he talks about it in this book : "Traité de physique et de philosophie" Fayard 2002.
here's the english version : http://www.amazon.com/Physics-Philosophy-Bernard-dEspagnat/dp/0691119643
It's an awesome read, even if you're not a physicist (I'm not !).
Re: FTL comms NOT
Basically it's all fun and games, until you want to actually read the data sent, as the start point of the sent data has to be sent sub light.
Re: FTL comms NOT
But if you time your measurements to do a Morse code reaction on the other end you could. Pauses between the scans would be the dots and dashes (or ones and zeros or whatever code you devise). The photons that are entangled become the transmitter not the information.
Re: But if you time your measurements
Nice idea, but you don't know the state of the doobly flop until you or someone else observes it. Also time is a bit bendy at distance.
Man, I don't even understand these comments !
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