Schrödinger's cat

[Stevodoc]

Dead or Alive? :confused:

[RXP]

You can't answer it without descriptions of when the wavefunction collapses iirc.

[the_GoDdEsS]

I'm not sure how this is related to Politics so I'll just redirect you.

[Endymion]

for the sake of not delving into technicalities and fancy shit, i'll leave it with what RXP said.

[clokey43]

Isn't the point of Schrodinger's cat explaination to prove that in the world of Quantum physics it is impossible to show what a particle is doing at a specific location in time and that if it isnt forbidden it is compulsory? This meaning that at the precise second beofre you open that box the cat is both as we cannot possibly know.

Its probably the best example of Quantum physics I have ever heard of and discussed.

[TheUnholyNightbringer]

I have no idea what any of this means.

[0r4ng3]

I have no idea what any of this means.
Oh good, I thought I was the only one who didn't.

[Endymion]

Isn't the point of Schrodinger's cat explaination to prove that in the world of Quantum physics it is impossible to show what a particle is doing at a specific location in time and that if it isnt forbidden it is compulsory? This meaning that at the precise second beofre you open that box the cat is both as we cannot possibly know.

Its probably the best example of Quantum physics I have ever heard of and discussed.

no. schodinger's cat is a relic from the early days of quantum mechanics when people had no clue what they were doing. even stephen hawking has been quoted as saying "when i hear about schrodinger's cat, i reach for my gun."

[clokey43]

no. schodinger's cat is a relic from the early days of quantum mechanics when people had no clue what they were doing. even stephen hawking has been quoted as saying "when i hear about schrodinger's cat, i reach for my gun."

Lol, I must admit when I first came across it i was like WTF but its a great example to confuse lil kids with! However, im a weirdo that loves quantum!

[rodney mullen]

Dead or Alive? :confused:
what are you talking about?????

[clokey43]

^^
http://media.techtarget.com/WhatIs/images/spacer.gif
Schrödinger's cat is a famous illustration of the principle in quantum theory (http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci332247,00.html) of superposition (http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci341263,00.html), proposed by Erwin Schrödinger in 1935. Schrödinger's cat serves to demonstrate the apparent conflict between what quantum theory tells us is true about the nature and behavior of matter on the microscopic level and what we observe to be true about the nature and behavior of matter on the macroscopic level.



Here's Schrödinger's (theoretical) experiment: We place a living cat into a steel chamber, along with a device containing a vial of hydrocyanic acid. There is, in the chamber, a very small amount of a radioactive substance. If even a single atom of the substance decays during the test period, a relay mechanism will trip a hammer, which will, in turn, break the vial and kill the cat. The observer cannot know whether or not an atom of the substance has decayed, and consequently, cannot know whether the vial has been broken, the hydrocyanic acid released, and the cat killed. Since we cannot know, the cat is both dead and alive according to quantum (http://whatis.techtarget.com/definition/0,,sid9_gci332244,00.html) law, in a superposition of states. It is only when we break open the box and learn the condition of the cat that the superposition is lost, and the cat becomes one or the other (dead or alive). This situation is sometimes called quantum indeterminacy or the observer's paradox: the observation or measurement itself affects an outcome, so that it can never be known what the outcome would have been if it were not observed. We know that superposition actually occurs at the subatomic level, because there are observable effects of interference, in which a single particle is demonstrated to be in multiple locations simultaneously. What that fact implies about the nature of reality on the observable level (cats, for example, as opposed to electrons) is one of the stickiest areas of quantum physics. Schrödinger himself is rumored to have said, later in life, that he wished he had never met that cat. - http://whatis.techtarget.com/definition/0,,sid9_gci341236,00.html
http://media.techtarget.com/WhatIs/images/spacer.gif

[wheaty]

I concure... :confused:

[Endymion]

the usual discussion of schrodinger's cat goes on to describe alleged quantum interference between the live and dead cat scenarios. however, the live cat has considerable interaction with the rest of the world, through breathing, for example, and even the dead cat interacts with the air to some extent. it doesn't help to have the cat placed in a box, because the box will interact with the outside world as well as with the cat. thus there is plenty of opportunity for decoherence between coarse-grained histories in which the at lives and coarse-grained histories in which it dies. the live and dead cat scenarios decohere; there is no interference between them.
suppose the quantum event that determines the fate of the cat has already occurred, but we don't know what happened until we pen a box containing the cat. since the two outcomes decohere, this situation is no different from a classical one where we open a box inside of which the poor animal, arriving after a long airplane voyage, may be either dead or alive, with some probability for each. yet reams of paper have been wasted on the supposedly weird quantum-mechanical sate of the cat, both dead and alive at the same time. no real quasiclassical object can exhibit such behavior because interaction with the rest of the universe will lead to decoherene of the alternatives.

[clokey43]

Its pretty simple really.


1) Place vial of hydrocyanic acid in box.
2) Add ramdomly decaying particle
3) Add cat and secure box.
4) Go back in an hour.

Is cat dead or alive, you cant know untill you open the box. Basically expliaining the statement of Quantum 'if its not forbidden its complusory' meaning if its not forbidden for the cat to be dead and alive then its compulsory so it is both. Even Schrödinger's wished he never though of it.

[Endymion]

Its pretty simple really.


1) Place vial of hydrocyanic acid in box.
2) Add ramdomly decaying particle
3) Add cat and secure box.
4) Go back in an hour.

Is cat dead or alive, you cant know untill you open the box. Basically expliaining the statement of Quantum 'if its not forbidden its complusory' meaning if its not forbidden for the cat to be dead and alive then its compulsory so it is both. Even Schrödinger's wished he never though of it.

put a retard in a meat freezer. wait two hours. dead or alive? won't know until we open it.

schrodinger died in '61, a lot has happened in the way of understanding the relationships between microstates and macrostates since then. the thought experiment is dead, the cat is either dead or alive, not in a superposition of both.

[wheaty]

Wow that is amazing. Good explination clokey. Why does he wish he didnt think of it though its not that complicated (after u get it)

[clokey43]

Im not entirely sure why he wish's he never thought of it all I can say is what I think. This is that is probably one of the most discused experiments to explain the theory, obvisuly people proving it to be and incorrect theoretical experiment. Its like something you say and you wish you had never bothered because it escolates out of proportion.

Endymion - I completely agree with your last statement. I admit that I found it diffuicult to conseive the fact that something can be dead or alive. However, I kind iof had to jus accept the fact , it was for my As level physics course. The experiment is definatly dead. Still a good one to confuse know it all kids as i said before lol.

[wheaty]

This is interesting...so what is Quantum Physics

[bongathon]

wahtser talking bout? i don't cget what cat hastas o wt things?

[Endymion]

i've studied much more than high school physics--trust me, the cat is *never* in a superposition state.

you'd be right in the physics of 1955, but not in that of 2005.

[wheaty]

ok what exactly does superposition state mean

[bongathon]

ok what exactly does superposition state mean

pou guys r lyke lod and stuff and smart..... lol roflQQQQQQQ

[wheaty]

This message is hidden because bongathon is on your ignore list.

[Endymion]

it's when a waveform has two or more valid eigenvalues prior to an observation.

[bongathon]

it's when a waveform has two or more valid eigenvalues prior to an observation.
sadfsdf
sd
f !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[wheaty]

it's when a waveform has two or more valid eigenvalues prior to an observation.
ok to save your time and myself from looking like an idiot I'll just google it :)

[RXP]

If you're interested in a laymen book on quamtum theory read "quantum reality".

[Endymion]

probably the most accurate laymen text that you can pick up for hella cheap is Feynman's QED. it's about the quantum mechanics of photons and electrons... about twenty years old now, but that particular field hasn't changed much other than being integrated with weak interactions to get the so-called electroweak theory.

[RXP]

quantum reality is a REALLY good book tho. I've only read the first 100 pages cause I kinda wanted to learn it rather than read it and it introduces you to how everything interelates and has a brief history of science too.

[Endymion]

i've heard it's good from a few other people as well.

[clokey43]

There is also a book called 'alice in quantum land' its a really good read.

[wheaty]

I'll check them out.
thx

[Mota Boy]

however, the live cat has considerable interaction with the rest of the world, through breathing, for example, and even the dead cat interacts with the air to some extent.
Pshaw, then just carry out the experiment in a vacuum. Problem solved. I'm really surprised more scientists don't come to me for help.

[Sin Studly]

If the cat is in two superposited states at the same time, both dead and alive, does that mean The Darkside has Cookies can eat it twice?

[Endymion]

Pshaw, then just carry out the experiment in a vacuum. Problem solved. I'm really surprised more scientists don't come to me for help.
you, sir, are my superior.

[clokey43]

if you put it in a vacuum surely there is a lack of ait for the cat so it will definatly die. (sorry if im being stupid feel free to abuse if i am)

[Endymion]

it was a joke...

anyway, it wouldn't defeat the reasoning because it would still interact via the weak electric field generated by its brain etc etc.

[wheaty]

Shit im lost this stuff is crazzy though

[clokey43]

Ok a joke now I get ya, im blonde find it difficult to catch on to such things lol.

You definatly know a lot about this stuff.

[Stevodoc]

Given that time is infinite, resulting in the fact that either of the answers is a possibility i would be inclined to say the cat is both dead and alive.

However based on the fact we will never know until we open the box, surely the only correct answer is "i dont know"...

[PXR]

Nothing is infinte.

[Endymion]

Given that time is infinite, resulting in the fact that either of the answers is a possibility i would be inclined to say the cat is both dead and alive.
look, if i put you in a box for a while i wouldn't say that you're both dead or alive. to even begin to ask such questions in the original cat question, you'd have to isolate COMPLETELY the cat from the rest of the universe, including possible neutrino interactions. this is impossible... so yeah, it's a moot point.

and yeah, time isn't infinite in *any* current theories. the nature of time isn't even close to being understood so it's a vague possibility that that could change but givin that the vast majority of physics the past 100some years has been marching toward discrite and finite, rather than continuous an infinite, it's highly doubtful.