Time Symmetric Interpretation

DrChinese

I'm glad you noticed! Modesty is one of my finest virtues.

And those *** Nobel folks. Don't get me started on them. They actually insist I DO SOMETHING IMPORTANT before I get my prize. Can you imagine...

DrChinese

You ARE funny, I guess I missed this side of you in our earlier discussion. Yes, I will be glad to make him say whatever you like. Especially things that are exactly opposite to his position. Do you want me to have him vote some particular way too? Or send you money?

Fyzix

You don't even comprehend sarcasm...
And you have ruined a thread on a useful interpretation because of your obsession with randomness.
Why are you so hung up on randomness? Is it like those other idiots who NEED free will?

someone just delete this thread, DrChinese has made it completely worthless

Fredrik

No, you did. He wrote a good answer. You replied with insults and have been increasingly aggressive ever since.

Fyzix

Nope, not at all :)
He kept INSISTING that TS would be just as random as copenhagenism, I told him to read the article, but he just refused and continued to say "it is random it is random it is random!".

If this TSI is random then dBB would be random too.
just because the variables aren't accesible to humans doesn't mean the universe in it self is random, man how arrogant can humans be!?

DrChinese

Sniff now my feeling are hurt...

Fredrik

Good to see that you haven't lost your ability to deny the obvious.

It is.

Why would he read the article? Why would anyone? Some of us know a little about the topic already, and you didn't even bother to point out the parts of it that you think support your claim.

Fyzix

Aharonov accepted that a particle’s past does not contain enough information to fully predict its fate, but he wondered, if the information is not in its past, where could it be? After all, something must regulate the particle’s behavior. His answer—which seems inspired and insane in equal measure—was that we cannot perceive the information that controls the particle’s present behavior because it does not yet exist.
“Nature is trying to tell us that there is a difference between two seemingly identical particles with different fates, but that difference can only be found in the future,” he says. If we’re willing to unshackle our minds from our preconceived view that time moves in only one direction, he argues, then it is entirely possible to set up a deterministic theory of quantum mechanics.

Satisfied?

DrChinese

Doesn't even remotely support your assertion.

DrChinese

Talking about not reading the article, I gave Fyzix a reference to a key work by the scientists mentioned in the Discover article. Obviously he has not read or understood it. From the paper "New Insights on Time-Symmetry in Quantum Mechanics" by Yakir Aharonov and Jeff Tollaksen:

http://arxiv.org/abs/0706.1232

"Contextuality (2.3) suggests that the measuring-device determines the
sets of possible micro-states [69, 70, 32]."

I.e. theirs is a contextual interpretation which an outcome is one of a set of possible states. They also mention that there is both a future component of a wave function and a past/present component which interact. Wave functions, of course, being closely related to the probability amplitudes for outcomes.

And nowhere do I see a claim that they have a way to predict outcomes based on future variables, nor that theirs is a realistic theory. All they are doing is working with an extra degree (half degree?) of freedom.

Thanks Fredrik.

Fyzix

..... I never stated, nor did they, that they would ever predict outcomes.
That is BEHIND THE CURTAIN. outside of reach for us!

DevilsAvocado

Why are you so hung up on determinism? Is it like those other maladroit’s who NEED someone to tell them what to do?

But, I suspect you did not check out the basic facts (again?), because there’s no automatic coupling between determinism & free will:



True, a lot of puffy arrogance right there. Maybe we could get a slightly more fruitful environment if you would stop telling The Universe how to behave...

Wait, I just got an idea! Why don’t you call Professor Emeritus Walter Lewin and tell him to squeeze that slit juuuuuuuuuust a little bit more, so that we once and for all can get a look of these darned in inaccessible variables!

http://www.youtube.com/watch?v=KT7xJ0tjB4A


Or, we just have to accept the strikingly decisive physical fact – this the way the world works...

DrChinese

I know they didn't. But you did, because you do not understand the difference between:

1. A theory in which we cannot predict an outcome because we can't know all the input parameters - sometimes referred to as stochastic. Throwing dice is considered a stochastic process as are stock market fluctuations. There are just too many parameters to learn precisely.

2. A theory in which even with all the input parameters known, no certain prediction is possible - sometimes referred to as non-deterministic. QM is such.

TSQM is of type 2. Suppose we have 4 variable parameters, 2 in the past and 2 in the future. Knowing any 3 should allow you to predict the 4th in a deterministic theory. You cannot do that with TSQM. And it matters not whether there are 4 or 4000 parameters, you still cannot predict the last one with certainty.

That is not to say that you could not attempt to develop a theory which is deterministic. But that has not been done yet for one which is time symmetric.

Demystifier

If it helps, I also think that the Aharonov time-symmetric interpretation is purely probabilistic (and therefore not deterministic), while dBB interpretation is deterministic.

DrChinese

Thanks for your comment!

joseph0887

Hi,
I'm a real late comer to this thread, and a new comer to these forums in general.

Dr.Chinese I think I understand what you mean, I'll attempt to put it in my own words, maybe you could tell me if I've gone wrong:

"The Time Symmetric Interpretation cannot be called deterministic as future events cannot be predicted even with perfect knowledge of a systems past."

At this point I have 2 questions:
1. Do Time Symmetric interpretations, in redefining causality, similarly redefine determinism?
It seems related to the philosophical concept of the B theory of time.

http://plato.stanford.edu/entries/time/#TheBThe

2. Could Time Symmetric interpretations be said to be ontologically realist, rather than epistemologically realist?

Also a brief question. How does retrocausality prevent the transfer of information back in time, and the grandfather paradox? I confess the mathematics are beyond me, so I wondered if there are any appropriate analogies? Well the question is brief, an answer may not be.

Another brief question, maybe DeMystifier will answer. Do Lorentz Invariant versions of the deBB interpretation also invoke retrocausality?

Thankyou for your consideration.

audioloop

...Finally, this experiment sheds a new light on the age-old question of free
will. Apparently, a measurement's anticipation of a human choice made
much later renders the choice fully deterministic, bound by earlier causes.
One profound result, however, shows that this is not the case. The choice
anticipated by the weak outcomes can become known only after that
choice is actually made. This inaccessibility, which prevents all causal
paradoxes like “killing one's grandfather,” secures human choice full
freedom from both past and future constraints...

http://arxiv.org/ftp/arxiv/papers/1206/1206.6224.pdf