Right Hand Rule - a question

[adman (Adam)]

Originally Posted by mithrandir

Back in the mists of time near the start of this thread, several people including me, said it was all to do with conventions.

yes- there were a few voices of reason early on

[sjastro]

Mark,

With regards to your original query you should employ "puddle thinking" to give you the answer.

". . imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it's still frantically hanging on to the notion that everything's going to be all right, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for."

This is Douglas Adams taking the mickey out of the Anthropic Principle.

Steven

[Jarvamundo (Alex)]

If you all think that Young's experiment is counter intuitive. It has been with done with Buckyballs C60 going through two slits as a wave function and then producing a diffraction pattern wth itself! It is really a measure of reality. Nothing actually exists as matter, just wave functions until it interacts. All possible paths are being followed until you take a peek and then the whole lot collapses into your reality. A bit like when you check to see what your kids are doing.

This is the whole quantum mechanics vs classical "field" physics dilemma, cause and effect with c as the limit.

I agree, i'm with you on the, the field propagates as a wave or field, and is 'measured' as a photon.

As you've pointed out, the role of the observer effects result, also the how the effects of the observer can effect the probability of result, seemingly beyond the limit of c SR. Of which is address in GR no? I've got some cool videos somewhere on these experiments...

Resident well versed relativist SJ is probably best to comment here...

The weirdsh#tometer continues to bend the needle.
http://www.scientificamerican.com/bl...ngl-2008-08-13

[renormalised (Carl)]

The weirdsh#tometer continues to bend the needle.
http://www.scientificamerican.com/bl...ngl-2008-08-13

Looks like that weird fecal matter-o-meter has hit the site....they're down and out at present

[Jarvamundo (Alex)]

Originally Posted by renormalised

Looks like that weird fecal matter-o-meter has hit the site....they're down and out at present

you obviously affected the result by 'observing' carl... it's back up now...?

Nature link here if need be: http://www.nature.com/nature/journal...080814-10.html

[renormalised (Carl)]

Originally Posted by Jarvamundo

you obviously affected the result by 'observing' carl... it's back up now...?

Nature link here if need be: http://www.nature.com/nature/journal...080814-10.html

Did you read the last sentence in that blurb about the experiments??. Basically what they're saying is this...they found, in their experiment, that the lower limit on the speed of quantum entanglement is at least 10000c. Therefore (and taking into account SR) it can't happen in nature. What a ridiculous statement!!!! If they were testing QE in this experiment, then how in the hell could it be a "hypothetical" spooky action if that's what they were actually testing between two particles, or whatever they were testing. It's only hypothetical if it's modeled in a computer simulation or simulated in some other fashion....not actually put to the test. They just don't like the results they came out with to be something which could occur in nature because the great god Einstein says it's not possible. Or the fact he didn't like it and didn't really understand it.

That's what annoys me...scientists wanting to hold onto cherished notions even when experiments/observations fly in the face of those notions. It's alright saying "but it holds up under every other thing we've done and it works...blah blah blah", but when something comes up which says otherwise then they've got to find all the excuses to say it's not going to happen...even if they actually see it happening.

[Nesti (Mark)]

Originally Posted by renormalised

Did you read the last sentence in that blurb about the experiments??. Basically what they're saying is this...they found, in their experiment, that the lower limit on the speed of quantum entanglement is at least 10000c. Therefore (and taking into account SR) it can't happen in nature. What a ridiculous statement!!!! If they were testing QE in this experiment, then how in the hell could it be a "hypothetical" spooky action if that's what they were actually testing between two particles, or whatever they were testing. It's only hypothetical if it's modeled in a computer simulation or simulated in some other fashion....not actually put to the test. They just don't like the results they came out with to be something which could occur in nature because the great god Einstein says it's not possible. Or the fact he didn't like it and didn't really understand it.

That's what annoys me...scientists wanting to hold onto cherished notions even when experiments/observations fly in the face of those notions. It's alright saying "but it holds up under every other thing we've done and it works...blah blah blah", but when something comes up which says otherwise then they've got to find all the excuses to say it's not going to happen...even if they actually see it happening.

A song from the Goodies might be timely, "String-string string-string, everybody loves string"

[Nesti (Mark)]

Originally Posted by sjastro

Mark,

With regards to your original query you should employ "puddle thinking" to give you the answer.

". . imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it's still frantically hanging on to the notion that everything's going to be all right, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for."

This is Douglas Adams taking the mickey out of the Anthropic Principle.

Steven

Well Steven, we seem to have come back to opinion and belief again, in that although all must agree that there is indeed determinacy within the universe - as there is predictable structure - but to what level it's expanse is unknown. Is it a determinacy/randomness/probability mix? Is it completely deterministic? We may never know.

Personally, my belief is that randomness and probability do not exist; they are akin to chaos theory before deterministic chaos. Chaos being a misnomer, which ultimately turned out to be just another gap in our understanding of the universe itself.

I also believe that 'Time Asymmetry' has a role to play, not in a classical sense, but in a QM and Relativistic sense. I believe that Action at a Distance can, and does, harmoniously feed into particle behavior, and that-that behavior is guided...not by any God related Mumbo-Jumbo, but by Time Asymmetry, whose sole purpose is to create that "Stable Reality" I keep mentioning about. Why is it that two completely identical experiments can produce vastly different outcomes? Is it simply a counter-intuitive property of matter at the QM level and completely normal, or is it perhaps the smoking gun of a type of particle time asymmetry, positioning the pieces of the dynamic puzzle at each and every moment in time and space, to ensure that stable reality actually becomes the reality. Such a protective property would be conservation of information and energy at its' finest...think about it for a minute. Particles which we think move and behave in mysterious ways could possibly be the outcome of a time asymmetric property of matter...and String Theory might just allow that through higher dimensional space, where SR might not be violated.

In this way, the Stable Reality removes the Puddle Thinking analogy altogether, and bypasses the entire argument.

Douglas Adams voiced his opinion in that analogy...no...he actually voiced his personal belief.

Cheers

[Jarvamundo (Alex)]

Particles which we think move and behave in mysterious ways could possibly be the outcome of a time asymmetric property of matter...and String Theory might just allow that through higher dimensional space, where SR might not be violated.

Or c aint the limit

Time doesn't slow down, its the clock

Dingles Question

University of London Professor Herbert Dingle showed why special relativity will always conflict with logic, no matter when we first learn it. According to the theory, if two observers are equipped with clocks, and one moves in relation to the other, the moving clock runs slower than the non-moving clock. But the relativity principle itself (an integral part of the theory) makes the claim that if one thing is moving in a straight line in relation to another, either one is entitled to be regarded as moving. It follows that if there are two clocks, A and B, and one of them is moved, clock A runs slower than B, and clock B runs slower than A. Which is absurd.

Dingle's Question was this: Which clock runs slow? Physicists could not agree on an answer. As the debate raged on, a Canadian physicist wrote to Nature in July 1973: "Maybe the time has come for all of those who want to answer to get together and to come up with one official answer. Otherwise the plain man, when he hears of this matter, may exercise his right to remark that when the experts disagree they cannot all be right, but they can all be wrong."

The problem has not gone away. Alan Lightman of MIT offers an unsatisfactory solution in his Great Ideas in Physics (1992). "[T]he fact that each observer sees the other clock ticking more slowly than his own clock does not lead to a contradiction. A contradiction could arise only if the two clocks could be put back together side by side at two different times." But clocks in constant relative motion in a straight line "can be brought together only once, at the moment they pass." So the theory is protected from its own internal logic by the impossibility of putting it to a test. Can such a theory be said to be scientific? --TB

[Nesti (Mark)]

Originally Posted by Jarvamundo

"According to the theory, if two observers are equipped with clocks, and one moves in relation to the other, the moving clock runs slower than the non-moving clock. But the relativity principle itself (an integral part of the theory) makes the claim that if one thing is moving in a straight line in relation to another, either one is entitled to be regarded as moving. It follows that if there are two clocks, A and B, and one of them is moved, clock A runs slower than B, and clock B runs slower than A. Which is absurd."

I disagree with this entirely...nothing happens to any of the clocks in uniform motion, nothing! It is the space and time in which the clocks' resides which changes, certainly not the clocks themselves. Space and time are flexible, not clocks or even trains. This is why tidal forces occur in bodies within a gravitational field; converging frames of reference cause bodies to converge, collide and/or create stresses on molecular bonds. Matter is not changing, the space and time in which matter resides is forcing change...but matter itself creates the properties of the space and time in which it sits...weird!

If the universe were completely empty except for two clocks at either end, billions of light-years away, with no possible way of comparing relativistic events, even through interactions of light, and if these two clock were moving in opposite directions, not knowing which one was really moving (which is a mute point anyway), I believe that there would be no distortion of space and time as there has not been, and cannot be, any interaction. Bring those two clocks close enough for light to interact, and relativistic effects would immediately become apparent (albeit at c).

I feel that the universe is built upon the properties of light, and that light, in fact all matter, carry information in the form of frequencies, and these frequencies can create energetic connections (entanglement) between two separate frames of reference, and these can remain connected until the frequencies are changed (disentanglement); this is yet another reason why String Theory offers me a great deal of logical reasoning, holds the promise of merging relativity with QM.

I know these comments are not verifiable, but that's why I used the words "feel" and "believe"...but nobody knows the truth anyway.

[sjastro]

University of London Professor Herbert Dingle showed why special relativity will always conflict with logic, no matter when we first learn it. According to the theory, if two observers are equipped with clocks, and one moves in relation to the other, the moving clock runs slower than the non-moving clock. But the relativity principle itself (an integral part of the theory) makes the claim that if one thing is moving in a straight line in relation to another, either one is entitled to be regarded as moving. It follows that if there are two clocks, A and B, and one of them is moved, clock A runs slower than B, and clock B runs slower than A. Which is absurd.

This is not even original, it's simply the twin paradox.
The moving clock will run slower.
The key to the problem is that the moving clock needs to be returned to it's original position in space (not space time) in order to compare the times elapsed on each clock. This destroys the symmetry aspect of the paradox.
The stationary clock's world line "moves" along a straight line in space time (along the t-axis), the moving clock moves along an oblique worldline (including the t and x axis) but inside the light cone of space time.

Here is the full explanation involving Minkowski space time diagrams.

http://en.wikipedia.org/wiki/Twin_paradox

Regards

Steven

[circumpolar (Matt)]

Originally Posted by sjastro

This is not even original, it's simply the twin paradox.
The moving clock will run slower.
The key to the problem is that the moving clock needs to be returned to it's original position in space (not space time) in order to compare the times elapsed on each clock. This destroys the symmetry aspect of the paradox.
The stationary clock's world line "moves" along a straight line in space time (along the t-axis), the moving clock moves along an oblique worldline (including the t and x axis) but inside the light cone of space time.

Here is the full explanation involving Minkowski space time diagrams.

http://en.wikipedia.org/wiki/Twin_paradox

Regards

Steven

Another way to think about it is that one clock must be under an acceleration (either + or -). This breakes the symmetry.
If both clocks experience the same accelerations then the symmetry between them remains.

[sjastro]

Originally Posted by circumpolar

Another way to think about it is that one clock must be under an acceleration (either + or -). This breakes the symmetry.
If both clocks experience the same accelerations then the symmetry between them remains.

Correct. Einstein also argued that the moving clock when under acceleration would undergoe gravitational time dilation via the equivalence principle.

Regards

Steven

[sjastro]

Originally Posted by renormalised

Did you read the last sentence in that blurb about the experiments??. Basically what they're saying is this...they found, in their experiment, that the lower limit on the speed of quantum entanglement is at least 10000c. Therefore (and taking into account SR) it can't happen in nature. What a ridiculous statement!!!! If they were testing QE in this experiment, then how in the hell could it be a "hypothetical" spooky action if that's what they were actually testing between two particles, or whatever they were testing. It's only hypothetical if it's modeled in a computer simulation or simulated in some other fashion....not actually put to the test. They just don't like the results they came out with to be something which could occur in nature because the great god Einstein says it's not possible. Or the fact he didn't like it and didn't really understand it.

That's what annoys me...scientists wanting to hold onto cherished notions even when experiments/observations fly in the face of those notions. It's alright saying "but it holds up under every other thing we've done and it works...blah blah blah", but when something comes up which says otherwise then they've got to find all the excuses to say it's not going to happen...even if they actually see it happening.

The editor's summary is woefully inadequate.
For example what is the exact nature of the test?

From what I have seen in one of the attached summarys it appears to be yet another photon polarizing test.

If so then Bells inequality is violated, there is no communication faster than light because there is no communication between the photons in the first place.

It is the No Communication thoerem at work.
http://en.wikipedia.org/wiki/No-communication_theorem

Regards

Steven

[Jarvamundo (Alex)]

Originally Posted by circumpolar

Another way to think about it is that one clock must be under an acceleration (either + or -). This breakes the symmetry.
If both clocks experience the same accelerations then the symmetry between them remains.

So with reference to this twins paradox thought experiment?

How does this differ from the aether style definition, of the moving clock moving through the aether (light carrying medium) and the clock it'self slowing down, because the matter in the clock (electrons, etc etc etc) have to travel further, therefore appears to have 'slowed time'?

[renormalised (Carl)]

Originally Posted by sjastro

The editor's summary is woefully inadequate.
For example what is the exact nature of the test?

From what I have seen in one of the attached summarys it appears to be yet another photon polarizing test.

If so then Bells inequality is violated, there is no communication faster than light because there is no communication between the photons in the first place.

It is the No Communication thoerem at work.
http://en.wikipedia.org/wiki/No-communication_theorem

Regards

Steven

I only had the chance to read the summary (didn't want to fork out the money to buy the paper!!...or go through the uni to get it )

I'll have another look later

[renormalised (Carl)]

You know, when all things are said and done, does the right hand really know what the left hand is doing??

[Robert9 (Robert)]

As best I can recall, given that it is more than 50 years ago since I studied Form 5 physics, the direction of the magnetic field was related to, or perhaps defined by the direction of the deflection of a compass needle placed above the conductor. Or have the years befuddled my aging brain - which would not surprise me!
The use of the hand just made a convenient method of remembering which way things went.

Robert