08 Sep 10
Originally posted by PalynkaIt depends on how you interpret Bell's inequality. If you take it to imply nonlocality, the "reaction" is instantaneous (or at least faster than light) but you can't "make something happen" faster than light.
Is reaction possible without any new information?
So for example, if you regard a quantum entanglement experiment where 2 particles are created with opposite spin and you measure one a very large distance away from the other to be spin up, the other will be spin down. But the other experimenter at the spin down particle won't be able to do anything with that information unless he's told the particle is spin down, which requires an information transport slower than light (e.g. over a telephone).
08 Sep 10
Originally posted by KazetNagorraBut then you're using the word reaction loosely, right? I noticed that now you put quotation marks around it.
It depends on how you interpret Bell's inequality. If you take it to imply nonlocality, the "reaction" is instantaneous (or at least faster than light) but you can't "make something happen" faster than light.
So for example, if you regard a quantum entanglement experiment where 2 particles are created with opposite spin and you measure one a very lar ...[text shortened]... down, which requires an information transport slower than light (e.g. over a telephone).
I was confused because I always assumed action/reaction required force and therefore information. If my assumption was wrong, what would be a better definition for reaction?
09 Sep 10
Originally posted by KazetNagorraWhat's a "quantum physicist."
As a quantum physicist myself, I don't easily get shocked at nature being weird anymore...
I teach Modern Physics at a state university. Having been in the field for five years now, I've never once heard a physicist describe themselves as a "quantum physicist."
On a side note, I've never even heard someone who was even remotely acquainted with the field use the term "quantum physics." Though obvious laymen and crackpots tend to reveal themselves by using the term.
09 Sep 10
Originally posted by sharpnovaMIT OpenCourseWare has courses named Quantum Physics (I, II and III). Do you think they are remotely acquanted with the field over there?
On a side note, I've never even heard someone who was even remotely acquainted with the field use the term "quantum physics." Though obvious laymen and crackpots tend to reveal themselves by using the term.
09 Sep 10
Originally posted by sharpnovaYour paranoia is noted. To be specific, I am a master student and will graduate in a couple of months. Currently working on BEC theory, which would make me a physicist specializing in quantum physics; i.e. a quantum physicist. Perhaps you have never heard the term because English is not my mother tongue.
What's a "quantum physicist."
I teach Modern Physics at a state university. Having been in the field for five years now, I've never once heard a physicist describe themselves as a "quantum physicist."
On a side note, I've never even heard someone who was even remotely acquainted with the field use the term "quantum physics." Though obvious laymen and crackpots tend to reveal themselves by using the term.
09 Sep 10
Originally posted by sharpnovaPeople usually describe themselves as Theoretical Physicists if their interest is in Quantum Mechanics.
Not paranoid. Was just trying to figure out why you were using that wording.
People usually describe themselves as Theoretical Physicists if their interest is in Quantum Mechanics.
You're studying BEC specifically?
Well, that would be confusing, because there are also experimentalists in the field.
You're studying BEC specifically?
Yes, something specific within that field (for my master thesis).
09 Sep 10
Originally posted by KazetNagorraNot to be picky but my son-in-law is a statistical physicist, used to be called bio-physics, but he didn't call himself a physicist till he got his Phd. He is finishing a book on foraging, it seems there is physics in the way animals forage for food. That work will help environmentalists track wild animals in the field and such.
[b]People usually describe themselves as Theoretical Physicists if their interest is in Quantum Mechanics.
Well, that would be confusing, because there are also experimentalists in the field.
You're studying BEC specifically?
Yes, something specific within that field (for my master thesis).[/b]
09 Sep 10
2 edits
Originally posted by PBE6Pearls before a swine I might assure you.
I thought for sure someone was going to pull out a phaser or trigger a paradox machine or somesuch.
Just like someone said I have yet to encounter someone to describe himself as a quantum physicist...
And people that work in BEC usually are called condensed matter physicists... I'm just saying though...
09 Sep 10
Originally posted by adam warlockMaybe you can answer my question:
Pearls before a swine I might assure you.
Just like someone said I have yet to encounter someone to describe himself as a quantum physicist...
And people that work in BEC usually are called condensed matter physicists... I'm just saying though...
Is reaction possible without any new information? I always assumed action/reaction required force and therefore information. Is there a precise definition for what reaction means in physics?
09 Sep 10
Originally posted by adam warlockYes, that must be why papers concerning BEC are usually found in PRA and not in PRB...
Pearls before a swine I might assure you.
Just like someone said I have yet to encounter someone to describe himself as a quantum physicist...
And people that work in BEC usually are called condensed matter physicists... I'm just saying though...
09 Sep 10
Originally posted by PalynkaTo start things off let me just say that the comment that incited my first reply on this thread was the most half-baked attempt that I ever saw in trying to popularize entanglement and Bell's inequalities (later comments weren't exactly stellar either, mind you)
Maybe you can answer my question:
Is reaction possible without any new information? I always assumed action/reaction required force and therefore information. Is there a precise definition for what reaction means in physics?
When you are in QM the concept of force makes no sense whatsoever and so this talk of action/reaction and forces makes no sense at all.
I'm assuming of course you and Mr. quantum physicist are using those terms in their everyday usage for any self-respecting physicist.
There is pretty good definitions to what reaction means in physics. You could be using it as in action-reaction pairs (in which case such usage is totally wrong in QM), or can you can be using as a synonym for feedback.
And I think that this usage might have some kind of marginal use to all of this...
Now the gist of entanglement, Bell's inequalities and all of this really comes down to QM ontology. The thing is that ontologically speaking orthodox QM rests on the shoulders of Fourier analysis. And any self-respecting physicist/mathematician (even quantum physicists I suspect and hope) knows that FA is non-local.
So a physical theory that rests on a nonlocal mathematical theory is nonlocal too. Having this in mind Bell's inequalities are hardly surprising and what really is the experimental confirmation of these results.
One excellent way for you to know a little bit about this is this excellent article: http://plato.stanford.edu/entries/qt-epr/
If you'd like a peek into the original article (something that any quantum physicist has surely peeked into) here you go: www.drchinese.com/David/EPR.pdf
If you have any question on the SEP article fire them away and I'll do my best, but just count me out of this action-reaction talk from now on.