quantum immortality

[TheVat]

http://en.wikipedia.org/wiki/Quantum_su ... mmortality

Feel free to post thoughts on this thought experiment. I favor Tegmark's position, that life/death situations do not have outcomes that hinge on single quantum events with binary choices.

[Faradave]

Aside from ethical considerations, I've never been convinced that macro systems, such as living organisms, enter a shared state (or the wave function). If the spin of a particle is the determinant it alone has a shared state and is subject to quantum update rules while we are subject to our own classical rules subsequent to that.

Life and death seem too discrete as employed in scenarios such as Schrödinger's cat. There's not a true shared state between them, only for the decaying isotope (determinant). It would be more applicable if the cat was simply boxed up after being cooled to a temperature where the known spontaneous survival is 50%. That might be considered a shared state between alive and dead, having some unknowable tipping element.

[Watson]

Another possibility is that although an observer does not die, they nevertheless continue to suffer the effects of aging, bringing to mind the legend of Tithonus.[6]

And the one observer survives 100 % of the many times and even the one that doesn't survive the latest time did survive a high percentage of the time.

[Marshall]

Hi Watson, BiV, Faradave,
There are a bunch of newer competing interpretations that get away from assuming there is one real wave function, and that it either must "collapse" in some mysterious physical way, or that reality must branch in some mysterious way (so that it won't have to collapse.
We've had threads about
Quantum Bayesianism
David Mermin's interpretation of it
Relational QM
Interactive Realism
The Oxford conference in 2013 with Rovelli, Tegmark, Saunders about cosmology and quantum foundations
I guess Tegmark's 2007 SciAm article that argues for MWI and reality of one unique wave function is a popularization.
He is an entertaining writer. But there are a lot of interpretations that avoid that kind of 1950 Everett branching reality, that he does not acknowledge in simplified account.

One we haven't talked about comes under the heading of Quantum Information Theory. I think one of the founders of that was the late Asher Peres, He taught in Israel, after escaping from Europe around 1940. One of the grand old men of physics.
He has an article I've seen referenced, the title suggests the theme, about the EPR paradox:
Asher Peres, “Einstein, Podolsky, Rosen, and Shannon” Foundations of Physics 35, 511-514 (2004)

Here's a quote from that Asher Peres article that Rovelli uses in his paper "Relational EPR":

“The question raised by EPR ‘Can the quantum–mechanical description of physical reality be considered complete?’ has a positive answer. However, reality may be different for different observers”

You could say that Asher Peres was hinting at a viewpoint we could call MOI, instead of MWI. That is an interpretation of quantum mechanics with "many observers" instead of "many worlds".

As in QB or Relational QM different observers may give different accounts of events, but subject to the limits on communication embodied in relativity they can explain their differences. We are used to that in Special and General Relativity, I guess it might be just a matter of carrying over the same kind of pluralism. :^)

[Marshall]

Here's a link to "Relational EPR"
http://arxiv.org/abs/quant-ph/0604064

In RelEPR or interactive realism nothing bizarre like the collapse of a physical wave function out there in nature happens. Everything is pretty commonsensical. Each observer has his package of information, his Hilbert space with vectors in it representing states, information, and he updates that as more information comes in, and...

ooops have to go help with supper

One point of this is that Tegmark, in his entertaining SciAm where he promotes MWI to lay audience, presents a false dichotomy between two rather ancient Interpretations, in each which something bizarre and nonsensical is imagined to occur. Either the Universe, our Reality FORKS or physical reality imagined as a unique real thing inexplicably COLLAPSES. In either case the "wave function" is imagined to be a real physical thing (not just an observers information). Maybe there is a God overseeing reality and it is HIS wave function describing how HE sees it. (Tegmark slips that idea in by talking about the "bird" and the "bird's eye view").

If the universe really splits (all the time all over the place wherever interactions occur) where does nature get the stuff to make all those universes and by what strange physical process? Likewise collapse, it is not the kind of thing we see other kinds of wave functions doing--unphysical. And it doesn't even solve the EPR paradox! which more recent "MOI" approaches like Relational QM or Quantum Bayesian do!

[Neri]

One must understand that all scientific theories are predictive tools, nothing more. Even the greatest theories contain assumptions that are preposterous on their face. Thus, Newton’s action at a distance, Einstein’s four-dimensional block universe, and Schrödinger’s equating of the potential with the actual simply make no sense. The wonder is that these theories work so well. Indeed, reality can lie within the four corners of these theories only if truth is identified as utility.

Obviously, Schrödinger’s cat (like any other cat) can be either alive or dead. There is no third possibility. Thus, the propositions, “the cat is dead” and “the cat is alive” cannot both be true. It is simply incoherent to say that a thing can, at the same time, be both the case and not the case. In certain instances, we cannot know if a cat is alive or dead. Yet, this is merely a statement of our own ignorance and does not change the fact that the cat must be either one or the other. Certainly, whether the cat is alive or dead may depend on an unpredictable contingency. However, this dependency does not justify the conclusion that the cat is somehow both alive and dead. Reality includes all that actually is-- not what could have been if a contingency had been otherwise. One can hardly imagine conclusions more rudimentary than these.

In an attempt to make sense of the senseless, atomic physicists have come up with a “beauty.” They tell us that the equal probabilities of life and death mean that the cat is already alive in one universe and dead in another, before the box is even opened. When the box is opened in this universe, the cat will be either alive or dead here--the remaining alternative being assigned to another universe. [It is never explained exactly how the choice is made between the universe in which the cat is dead and the universe in which the cat is alive.] This analysis, of course, necessitates the rather fantastic notion that every probability is actual in some universe and that, as a consequence, there is an unlimited number of alternate universes.

It should require little reflection to realize that a probability distribution is not as concrete reality but only a mathematical expedient. It is an idea that guarantees accurate predictions in atomic physics, yet it is still just an idea. Any attempt to make it more than it is will inevitably [from the philosophical perspective, at any rate] result in nonsense being heaped upon nonsense.

[wolfhnd]

I have been doing a bit of thinking on how an epistemological truth is not necessarily a scientific truth and vice versa. Mostly in relationship to the limits of what we can know about something and how that effects how true a statement may be. Within certain context it would be appropriate to say that the universe is deterministic if deterministic only means that there are laws that apply uniformly through out the universe. You have to keep in mind that laws are abstractions. From a scientific point of view the universe is probabilistic and there are limits to how finely any experiment can measure something. What quantum physics introduces is the possibility that the universe is "truly" probabilistic and the possibility that even abstractions such as a beginning and an end should not be absolute or knowable even if absolute measurements were possible. The human mind naturally recoils at the idea that there are things that are unknowable and will invent Gods or alternative universes to fill the void. Fortunately we have experimental scientists to restrain theoretical physics.

On a personal level I think that the questions raised by Quantum Mechanics have pushed me over the edge and I will reply to religious wackos more often with I don't know and I don't care.

[TheVat]

Regarding use of the MWH to achieve quantum immortality - the thread topic - I agree with Paul Davies that MWH is counter to Ockham's razor, and nothing but metaphysical hoodoo. In 1990, he wrote...


"Another weakness....is that it seems the very 
antithesis of Occam's razor, according to which the most plausible of a 
possible set of explanations is that which contains the simplest ideas and 
least number of assumptions. To invoke an infinity of other universes just 
to explain one is surely carrying excess baggage to cosmic extremes..."

(Davies P., "God and the New Physics", 1990, p173)

[Dave_Oblad]

Hi wolfhnd,

There should be no question that the Universe is Probabilistic. (it is!) The issue is that some folks equate Probabilistic with Randomness.. They are NOT the same thing. Pick a number from 1000 to 99,999. Take this number as an index into the sequential value of PI.. for example say you picked 54321. So go to the 54321th digit of PI and take the next two numbers. What are the odds those two digits defined will match the last two numbers of the index (21)? About 1/100? Yet PI is completely Causal.. not a random bone in its body. Probability is not Random. Causal systems can/must be treated as Probabilistic systems when the complexity (or lack of info) becomes too high to be easily determinate.

Best wishes,
Dave :^)

[hyksos]

So in a statistics class, the word "random" has a boring meaning. You can characterize the "randomness" of any given sample of things. Chapter 5 tells you how to do that. It's dry. No mysteries.

But in philosophy, many times the word "random" actually means something closer to "has no cause". If something is random in philosophy, it is capricious, inconsistent, and unpredictable. As Oblad pointed out, the digits of Pi are statistically random. However, a few lines of computer code can churn out the digits mechanically, meaning they are totally predictable.

[littletrio]

Max Tegmark, has a chapter dedicated to this topic in his book "Our Mathematical Universe", great read.....I might add. I first saw his named mentioned by Paul Davies in his "Goldilocks Enigma".

First heard Max speak at Hammeroff's Tucson Consciousness Conference. Felt like he had a heart of gold and that he was a empath. His genius mind reminds me of Campbell, Whitehead, and Wheeler. It is nice to see a intellectual look at it from all directions (out of the box) so to speak. He held up a copy of his book and I almost stood up and said how much for that signed copy (missed my chance); I had blown enough money on other expenses related to my travels (hence me neglecting my intuitions).

Max, if you by chance see this......how you felt about meeting Wheeler for the first time.....is how I felt when I was in the presence of Penrose and getting his signature on a hard copy of "The Road to Reality" (about shed a tear).

True story, first day of the Pre Conference and I was the first person to be in the Conference Hall/Room (probably seats 400). Anyway, Penrose and Hammeroff were scheduled to speak, so I say to myself.......Where will Penrose sit? Call this crazy intuition or luck, but I sat on the right hand side four rows back and what do you know.....Roger Penrose is sitting right in front of me. Sadly, I had this undergrad student (from a foreign country) who would fart like every 10 minutes. Can you imagine the horror going on in my mind with several of the leading minds of the world sitting right around me and a grad student continually stinking up the area. Finally, it got to the point that I had to say something (because he was just letting them rip after awhile and laughing) got right up into his face and told him to stop shitting on me and I repeated it. Fortunately, it worked and he stopped the flatulence campaign.