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dickbill
scholastic sledgehammer


Reged: 09/30/08

Re: Schrodenger's cat new [Re: Pess]
      #5844002 - 05/06/13 04:56 PM

...yes, until a measurement is taken. That means the geiger itself is enough to impose a single state out of the other possible states, since it makes the first measurement when a decayed particle interact with the detector.
It is however interesting how the quantum indetermination vanishes 'instantly'.


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Pess
(Title)
*****

Reged: 09/12/07

Loc: Toledo, Ohio
Re: Schrodenger's cat [Re: dickbill]
      #5844138 - 05/06/13 06:23 PM

Quote:

...yes, until a measurement is taken. That means the geiger itself is enough to impose a single state out of the other possible states, since it makes the first measurement when a decayed particle interact with the detector.
It is however interesting how the quantum indetermination vanishes 'instantly'.




I don't think the terms 'instant', 'now', 'then' 'before' after' have the same meaning at the quantum level as in the macro level.

I believe the proper linguistic description is that the 'waves of probability collapse into a certainty once a measurement is taken'.

So in your slit experiment if you look for the photon behaving as a wave its probability function (wave vs particle) collapses into a wave. If you detect it as a particle its probability function collapses into a particle.

But before the measurement the photon is in both states.

Pesse (Quantum objects have 'nuthing on Sybil) Mist


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deSitter
Still in Old School


Reged: 12/09/04

Re: Schrodenger's cat new [Re: Pess]
      #5844385 - 05/06/13 08:30 PM

Quote:

In the simplest terms, the math of Quantum theory states that a quantum particle sits in a state of superposition.

Since quantum particles can be describes as waves or particles the math states that they exist as both until the are measured (observed).

This state is called 'superposition". Since the 'final' state is determined by how the measurement is made.

Schrodenger looked at that and said, 'Well what if we link a non-quantum sized outcome to the outcome of that single quantum particle?' In other words, if the quantum particle decays it triggers the death of a Cat....

Since the end event is triggered by a particle in a superposition state, it follows that the Cat itself exists in a superposition o state (ie: both dead and alive) until a measurement is taken.

Pesse (Schrodenger failed to take into account the nine lives of cats) Mist


ve

You have forgotten how the initial state is prepared. You cannot calculate anything in quantum theory without specifying the initial state. All the stuff about superposition is meaningless without knowledge of the initial state.

-drl


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dickbill
scholastic sledgehammer


Reged: 09/30/08

Re: Schrodenger's cat new [Re: deSitter]
      #5845200 - 05/07/13 09:53 AM

"Since quantum particles can be describes as waves or particles the math states that they exist as both until the are measured (observed)."
The first measurement is when a decayed particle interacts with something, therefore the geiger detector is doing the first measurement. The quantum indetermination is lost long before the cat 'status' can be influenced and in no ways this indetermination can be transfered to a macroscopic cat.
Is it true?
Does the wave function of probability collapse completely? or is there a tiny remnant of quantum indetermination that could be transfered to a macroscopic system, either the geiger or the cat? so that instead of saying the cat is 50% dead or 50% alive, we'd say he is 99.999% dead or 99.999% alive.


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llanitedave
Humble Megalomaniac
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Reged: 09/26/05

Loc: Amargosa Valley, NV, USA
Re: Schrodenger's cat new [Re: dickbill]
      #5845243 - 05/07/13 10:15 AM

Whoo-hoo-hoo, look who knows so much. It just so happens that your friend here is only MOSTLY dead. There's a big difference between mostly dead and all dead. Mostly dead is slightly alive. With all dead, well, with all dead there's usually only one thing you can do.

What's that?

Go through his clothes and look for loose change.


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star drop
Snowed In
*****

Reged: 02/02/08

Loc: Snow Plop, WNY
Re: Schrodenger's cat new [Re: cavefrog]
      #5845405 - 05/07/13 12:06 PM

Quote:

I know I am in way over my head here, but I gotta ask someone! what is it that I am not seeing about this cat? If an atom decays, the cat is dead. well , that's easy enough. and if an atom does not decay, the cat is not dead. that seems to be another easy. so where is the overlap of the cat being BOTH dead and alive at the same time? is it the speed in which an atom MIGHT decay?
as I said, I am trying to understand something probably way over my head, so if someone cares to answer, please try to use layman's terms.

Thanks, Theo



If I may run with the question further I would like to delve deeper. In general terms very large atoms don't hang around very long. They sometimes emit multiple alpha particles at the same time. When these particles are in the process of forming in the large nucleus just before being emitted, what makes them special from the rest of the nucleons, can quantum theory explain why the helium nuclei are not ejected one by one as is the customary case? As they form are they quasi dead in respect to both the parent nucleus and the forming helium nucleus? Particle or wave, explain it either way in layman's terms if possible.


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TVG
member


Reged: 05/03/12

Re: Schrodenger's cat new [Re: Pess]
      #5845961 - 05/07/13 03:37 PM

What would happen in a similar experiment to the double slit if the same particle was measured multiple times with different expectations for a wave or a particle each time. In other words does the wave of probability collapse only once per particle per observance and that particle must remain in that state forever or does each new observance of the particle bring about a new state of existence. Sorry if that is a stupid question, but I am enjoying this thread immensely, even if it is way over my head.

Todd


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dickbill
scholastic sledgehammer


Reged: 09/30/08

Re: Schrodenger's cat new [Re: star drop]
      #5846006 - 05/07/13 04:09 PM

The 'cat in the box' is not the best example, it's probably the slit experiment that examplifies best the problem, according to the physicist Richard Feynman.

Take a single photon moving in the direction of a screen with 2 slits before he finally hits a screen or a camera.
If this photon is like the bullet of a gun, it will go through one slit since it cannot be at two different places in the same time. If instead the photon behaves like a wave, like we get on water, it will go through both slits at the same time and produce an interference pattern on the screen and camera.
Now, even if a photon is a particle, in quantum theory it can be in two places at the same time (with a probability given with a function), and produce an interference pattern like a wave. Even if you send photons one by one, one at the time, they will still produce an interference pattern, that is, until you don't 'observe' them.
If you put a detector under each slit to detect which slit the photon went through, the interference figure is destroyed. But as long as the photon is not observed, his position in space is really a superposition of possibilities, or states. That's because of the quantum nature of the photon, as opposed to a macroscopic object like a bullet with no quantum indetermination. That is, whether you observe a bullet or not, it will go through one slit only, not both.

Anyways, in the story with the cat, the quantum undertermination is supposed to be transfered to the cat which in this case, can be in a superposition of states dead or alive, as long as you don't observe it. The cat has become entangled with the original quantum event.

it's better described here
http://en.wikipedia.org/wiki/Quantum_entanglement

For those interested in the nature of the mind, we could ask if a quantum entanglement could somehow be transfered to 'brain activity'? the experiment i was refering above (human meditators focusing their mental attention on a remote slit apparatus), came from a blog site called 'Entangled Minds'. Now you understand the connection. Whatever we can think of it (of the Mind, forget the cat), i think it's a valid question to ask, and valid to test it by experimentation.

PS: i'm not the author of the blog.


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Mister T
Pooh-Bah


Reged: 02/01/08

Loc: Upstate NY
Re: Schrodenger's cat new [Re: llanitedave]
      #5846628 - 05/07/13 09:08 PM

he's not dead yet

he's almost dead

actually I'm feeling better


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llanitedave
Humble Megalomaniac
*****

Reged: 09/26/05

Loc: Amargosa Valley, NV, USA
Re: Schrodenger's cat new [Re: Mister T]
      #5846937 - 05/08/13 12:11 AM

You're not fooling anyone.

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cavefrog
Carpal Tunnel
*****

Reged: 11/11/08

Loc: loozyanna
Re: Schrodenger's cat new [Re: Mister T]
      #5846973 - 05/08/13 12:45 AM

well at least I got it that the cat can be let out of the box , fed, and sent on his way because he is only a distraction.
some things said are starting to fall in place. superposition is something I have not come across. this is my first exposure to it. the double slit experiment, I have read about before. I think I came across it in ham radio, but I seem to have a misconstrued understanding. I had the belief that the slit experiment was supposed to determine if "something" was a particle or a wave. I do think that something was a photon. again, a photon in my understanding has not been determined to be a particle or a wave, which makes it unknown whether it has mass or not. or maybe both?
fluctuating back and forth? is this where the superposition comes in? to add to this is a statement that I came across lately, that Heisenburgs uncertainy principle has often been confused with the "observers effect". again, as I understood, Heisenburgs uncertainy principle says something like a particles speed and position cannot both be determined at the same time. one can only know either speed OR position , but not both.
so... maybe none of this has anything to do with the subject, but if determining a particles state is dependent upon being observed at a particular monent... sure sounds like obsevers effect to me.
the way a lot of this stuff is linked together makes it all very confusing. I was running in circles with absolute zero questions too. but like I said, I grasp alittle here an there.
does any of this make any sense? or am I totally discombobulated?

somehow I feel its all connected!!!! :>)

Theo


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Rick Woods
Postmaster
*****

Reged: 01/27/05

Loc: Inner Solar System
Re: Schrodenger's cat new [Re: llanitedave]
      #5846998 - 05/08/13 01:19 AM

Quote:

You're not fooling anyone.




Look, isn't there something you can do?


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Pess
(Title)
*****

Reged: 09/12/07

Loc: Toledo, Ohio
Re: Schrodenger's cat new [Re: TVG]
      #5847344 - 05/08/13 09:00 AM

Quote:

What would happen in a similar experiment to the double slit if the same particle was measured multiple times with different expectations for a wave or a particle each time. In other words does the wave of probability collapse only once per particle per observance and that particle must remain in that state forever or does each new observance of the particle bring about a new state of existence. Sorry if that is a stupid question, but I am enjoying this thread immensely, even if it is way over my head.

Todd





You are reading far too much into the thought experiment. One event=one outcome.

All The Cat Thought Experiment was meant to show that if you link a quantum event to a macro event than superimposition applies equally to both the quantum AND macro world.

The implications of this idea is staggering. What it means at its most core level is that the physical world as we we perceive it doesn't exist until we sense some portion of it.

In other words, we form the Universe by our observation of it....

Pesse (I see it, therefore I am it) Mist


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dickbill
scholastic sledgehammer


Reged: 09/30/08

Re: Schrodenger's cat new [Re: Pess]
      #5847677 - 05/08/13 12:31 PM

"..All The Cat Thought Experiment was meant to show that if you link a quantum event to a macro event than superimposition applies equally to both the quantum AND macro world..."
Yes, that's the point of the tought experiment, except my understanding is that you cannot link a quantum event to a macro event and therefore a macroscopic system cannot be in a superimposition of states.
I mean any macroscopic system which entropy will change will provoke the probability function to collapse. And if the entropy has changed, the arrow of time has been activated.
If the entropy has not changed, it's because nothing has happened.
I wonder if it could be reworded as: as soon as the quantum event 'feels' the arrow of time, it ceases to exist as a superposition of states.


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Pess
(Title)
*****

Reged: 09/12/07

Loc: Toledo, Ohio
Re: Schrodenger's cat new [Re: dickbill]
      #5847690 - 05/08/13 12:37 PM

Quote:

...except my understanding is that you cannot link a quantum event to a macro event




The entire point Schrodeniger was making is that you CAN have a macro object in a superimposition state.


"arrow of time has been activated' Hunh?

Time is not an arrow, nor can it be described in isolation any more than you can talk about the length of an object and ignore its width and height.

Pesse (Spacetime is a better nom de plume) Mist


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dickbill
scholastic sledgehammer


Reged: 09/30/08

Re: Schrodenger's cat new [Re: Pess]
      #5848278 - 05/08/13 05:31 PM

I was refering to the definition popularized by Stephen Hawkins:"the arrow of Time points in the direction of increasing entropy".
That's in his 'Short History of Time' If i recall.

Schrodinger wanted to play games with this story with the cat. When he invented the story, maybe he was frustrated, or just drunk. Beside, the endresult of the experiment could be used to make a reductio ad absurdum: since not cat can be dead or alive, then no macroscopic system can be in a superposition of states and no macroscpic system can be entangled with a quantum event, and you might say it was exactly THAT point Schrodinger wanted to make.


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Pess
(Title)
*****

Reged: 09/12/07

Loc: Toledo, Ohio
Re: Schrodenger's cat new [Re: dickbill]
      #5848353 - 05/08/13 06:00 PM

Quote:

I was refering to the definition popularized by Stephen Hawkins:"the arrow of Time points in the direction of increasing entropy".
That's in his 'Short History of Time' If i recall.

Schrodinger wanted to play games with this story with the cat. When he invented the story, maybe he was frustrated, or just drunk. Beside, the end result of the experiment could be used to make a reductio ad absurdum: since not cat can be dead or alive, then no macroscopic system can be in a superposition of states and no macroscpic system can be entangled with a quantum event, and you might say it was exactly THAT point Schrodinger wanted to make.




I certainly can't argue with you. What you say might be valid. But regardless of Schrodenger sobriety at the time, his logic is not flawed: If superimposition as a state of a quantum particle is a valid state, then it follows that if you link a quantum event with that quantum particle to a macro event than both MUST be in superimposition states.

So what was Schrodeniger being absurd about? Superimposition of quantum particles in general?

And if it is so absurd, why has the world of physics so embraced the analogy?

We exist in a sea of unformed energy.

I actually don't have any problem embracing this concept. Eastern disciplines have long talked about the energy of the Universe. Even Motivational speakers understand the idea of positive thinking.

The Universe is a blank slate of energy. We give it form and function by our perception of it. Viewing things in a negative light can lead to negative views of our own unique universe (bad karma, bad energy, Poison Qi).

Physics is just now seeing this in the concept of quantum uncertainty. Certainty can only come AFTER perception (measurement).

Pesse (To control the Universe, one only has to see it in the proper light..) Mist


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Rick Woods
Postmaster
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Reged: 01/27/05

Loc: Inner Solar System
Re: Schrodenger's cat new [Re: Pess]
      #5848418 - 05/08/13 06:36 PM

Quote:

The Universe is a blank slate of energy. We give it form and function by our perception of it. Viewing things in a negative light can lead to negative views of our own unique universe (bad karma, bad energy, Poison Qi).

Physics is just now seeing this in the concept of quantum uncertainty. Certainty can only come AFTER perception (measurement).




I'm sure I'll be shot down here, but it seems to me that certainty is merely a function of our own perception of things. Things are what they are, whether we perceive them or not. If the cat is dead, it's dead whether we're sure of it or not. The falling tree made noise. Our perception of these events does not affect their objective reality (or lack of it). Why on earth would it?

I know, I know: We change the fact by observing it. But why do we think this? What makes us think things were one iota different before we observed them, than they were afterward?

What am I missing? It's been nearly 20 years since I read "Brief History of Time", and I've lost whatever edge I had back then on this stuff. But the cat, etc; it all just seems like sophistry to me.

OK, open fire. I can take it.


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deSitter
Still in Old School


Reged: 12/09/04

Re: Schrodenger's cat new [Re: Pess]
      #5848425 - 05/08/13 06:38 PM

The problem is, the cat does not have a prepared state. For example, the cat may be genetically resistant to cyanide. Classical statistical mechanics may cause the cyanide atoms to accumulate in the corner while the cat breathes free. Et cetera - I can invent a billion scenarios in which the cat is not connected to the microstate. There is no actual connection. The cat is simply a distraction. The states that are connected by superposition in an observable manner, must both be capable of being put into a prepared state - an eigenstate of the corresponding observable - and there is no operator of liveness or deadness. It's simply a pointless mind game. You can play the very same mind games with any logical system, including classical mechanics (tree falls etc).

-drl


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dickbill
scholastic sledgehammer


Reged: 09/30/08

Re: Schrodenger's cat new [Re: deSitter]
      #5848733 - 05/08/13 09:10 PM

Quote:

...and there is no operator of liveness or deadness. -drl




WHAT !, what are you waiting for?


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