Uncertain about uncertainty - and Zeno isn't helping!

[I'm Murrin]

It's just a thought experiment to get people to understand the concept of quantum uncertainty. It doesn't apply literally.

[Avatar]

And people don't get it anyway. Schrödinger was arguing against the Copenhagen interpretation, according to which it is the act of measurement that collapses the probability waveform. (Well, he was pointing out a flaw in it.)

In other words, until you open the box, both probabilities exist equally in potential, and the cat is alive and dead.

Schrödinger was saying that it can't be both alive and dead, it must be one or the other.

--A

[peter]

The key word in your above post Avatar is 'exist'. Dou you mean they exist equally in possibility, or in reality. In possibility, well of course - my boss might be dallying with the secretaary or he might be dictating a letter and I won't find out which till I open the door - or in reality which is much harder to visualise ie a sort of 'take this dictation Miss Jones..... (no I'm not even going to go down that road! )

NB I'm using a macro example as Shrodinger did but I know we are talking quantum stuff here, now at least. But what I'm really after is just to know what we are supposed to learn from te thought experiment - a succinct explicit statement "Shrodingers 'cat in the box thought experiment teaches us that.........." This type of thing so my simple head can go " Ahh yea. I get that.

[I'm Murrin]

Schroedinger's Cat teaches us that quantum uncertainty is absurd.



Unfortunately for Schroedinger, it also appears to be true.

[Fist and Faith]

I just watched the Quantum Mechanics episode of that Brian Greene series. It helped me a whole lot. Some very interesting ideas! (Is that what they call an understatement?)

Finally, a physicist named Max Born came up with a new and revolutionary idea for what the wave equation described. Born said the wave is not a smeared-out electron, or anything else previously encountered in science. Instead, he declared it's something that's really peculiar. A probability wave.

The basis of reality isn't a particle or a wave, but a probability!?

And how about that crazy entanglement stuff! I think Z mentioned this in my Paradox thread in the Close? Utterly insane stuff. And it says the only thing standing in the way of Clauser and a PhD in Astrophysics was his grade in QM. Then, he just happened to stumble across a paper by Bell. And he ended up building a machine that proved Bohr was right and Einstein wrong - that measuring does determine the spin, and the spin of the entangled particle; and the spins were not determined all along, and simple learned by measuring.

But I'll tell you something. If they do ever come up with that transporter for people, I'm not stepping into it! I don't care if a duplicate in every way comes out the other end, I'm still dying on this end!

[I'm Murrin]

But I'll tell you something. If they do ever come up with that transporter for people, I'm not stepping into it! I don't care if a duplicate in every way comes out the other end, I'm still dying on this end!

You know, I thought a lot about this one a few weeks back. I don't think it matters. There's certainly an existential fear, there, but really when you consider that you're nothing more than a biological machine, and that your self is an expression of its functions; and you consider that in reality every moment a past self ceases to exist and the present self replaces it, then copying yourself in such a way is no different, because what matters is not true continuity of the self, but the possession of a perception of continuity in the self that results.

[Fist and Faith]

But we can't know what perception we'll have. If it works as they think it will, the copy will certainly have that perception of continuity, and feel like it had been the original all along.

But the original might feel itself die. Or look at it this way. Maybe we could find a way to preserve the original, and have two of me running around. Could we kill the original? The copy has the true continuity anyway, so no harm done?


Edit: This conversation sounds familiar. Has it taken place at the Watch?

[Fist and Faith]

Oh! And quantum computers! Heh

[Vraith]

find a way to preserve the original, and have two of me running around. Could we kill the original? The copy has the true continuity anyway, so no harm done?


Edit: This conversation sounds familiar. Has it taken place at the Watch?

I know somewhere I mentioned a play about just this [in part, it dealt with a number of identity issues] called "On Ego."
They can teleport...but really it isn't the matter that moves, it's the information. The departing one is supposed to disintegrate, but once in a while it malfunctions and they end up with two that both think they're the real one. The one that was supposed to have "departed" they have to kill...because s/he is the mistake...the arrival "copy" is, just as you say, the continuous one because is what was supposed to happen.

BTW, another problem for Standard Mode from LHC, possibly. Matter and antimatter siblings decay in different ways way more than they're supposed to. They need more data, but it's trending that direction.

[peter]

There's been a lot of fuss of late about this buisiness of neutrinos travelling faster than the speed of light in some expt over in Geneva, but wasn't the writing on the wall for a big hunk of Einstein's stuff the moment that quantum entanglement began to be proposed?

[Avatar]

Schroedinger's Cat teaches us that quantum uncertainty is absurd.



Unfortunately for Schroedinger, it also appears to be true.

Exactly.

--A

[Vraith]

Quantum objects don't have definite properties prior to measurement, they merely have probabilities of having certain measured properties. They aren't just uncertain, they are indeterminate, due to their wavelike nature and behavior.

there may be a better thread and quote to attach this to, but I'm too lazy to do a bunch of searching, and this is kinda sorta close enough...the dual nature/indeterminancy/quantum may be getting closer and closer to us:
apparently it extends, at least in some cases, beyond the tiny/particle level, up to the pretty large molecular level [114 atoms]

news.yahoo.com/largest-molecules-yet-behave-waves-quantum-double-slit-184107270.html

[Hashi Lebwohl]

Fascinating. I wonder how large a molecule has to be before it stops causing interference patterns, at which point it does not demonstrate wave-like behavior? If we can find that mass, then we have a limit below which quantum behavior is dominant and above which classical behavior is dominant. The research would then focus on the barrier itself, trying to design things take can take advantage of quantum behavior on a classical scale.

[I'm Murrin]

Previously the largest matter that had been shown to demonstrate the behaviour was Buckminsterfullerene.

[Hashi Lebwohl]

Haven't they recently detected fullerenes in space? I remember being introduced to them in organic chemistry...back in 1988. I have forgotten more chemistry than most people will ever know, sadly.

[Vraith]

Haven't they recently detected fullerenes in space? I remember being introduced to them in organic chemistry...back in 1988. I have forgotten more chemistry than most people will ever know, sadly.

it's in both regular soot, and in deep space IIRC. [yep, just checked M's wiki link, and it says so]. On a somewhat related [really have to stretch in a certain way to make that claim] I also saw recently that in at least some circumstances they can "trick" electrons...a concept that one of the Big B writers [probably Benford] used in a book years ago..."tricking" particles so inertia didn't apply was the prime thing IIRC.

www.popsci.com/science/article/2012-03/ ... re-devices

[peter]

Schroedinger's Cat teaches us that quantum uncertainty is absurd.



Unfortunately for Schroedinger, it also appears to be true.

Exactly.

--A

Schrodinger knew this though. I think I mentioned in another post that on one occasion he gave a talk where he almost had to apoligetically admit that the likelyhood was that his equations were true (as opposed to the Copenhagen Interpretation's version of quantum theory).