Mart Posted January 25, 2005 Share Posted January 25, 2005 In this thought experiment a live cat was placed in a box with some device which could render it live or dead after some specified time. Schroedinger noted that the device's outcomes could be represented mathematically (his wave equation). Because the outcomes of the equation are "indeterminate" (unknowable until known) he suggested that the cat's status was indeterminate and it was in a "superposition of states" that is, neither live or dead. Do you think that (a) Schroedinger was trying to point out the absurdity of applying QM to the world in which cats live or (b) you know the physical process whereby a live cat can be rendered neither live or dead by being placed in a box Link to comment Share on other sites More sharing options...
swansont Posted January 25, 2005 Share Posted January 25, 2005 a. If whatever event that kills the cat happens, and the cat were left for a long time, it would start to decompose. Obviously it wouldn't really be in a superposition of states until you lifted the lid. Link to comment Share on other sites More sharing options...
ed84c Posted January 25, 2005 Share Posted January 25, 2005 a) The cat knows whether its dead or alive. Its a bit arrogant to prosume if we cant see a cat there are therefore infinate universes (missing a few steps iknow) Link to comment Share on other sites More sharing options...
Mart Posted January 25, 2005 Author Share Posted January 25, 2005 If whatever event that kills the cat happens, and the cat were left for a long time, it would start to decompose. Obviously it wouldn't really be in a superposition of states until you lifted the lid. The cat according to Schroedinger IS in a superposition of states while it's in the box. Started live, then into box, then after a short time either dead or alive. Link to comment Share on other sites More sharing options...
Klaynos Posted January 25, 2005 Share Posted January 25, 2005 I belive the taken form of death is radioactive isotope, as radiation is random the time is unknown, so placing the cat in the box and closing the box the cat could be dead from the radiation and is dead in some universes (if you belive in multiple universes that is) whereas in other universes the cat is still alive as the radiation is yet to kill it due to it's randomness. We do not know whether the cat is dead or alive untill we open the box. QM is absurded it has been commented on many times that if you think you understand QM then you are just fooling yourself. Link to comment Share on other sites More sharing options...
JaKiri Posted January 25, 2005 Share Posted January 25, 2005 (a) Schroedinger was trying to point out the absurdity of applying QM to the world in which cats live Or, stated more generally, the absurdity of applying QM to macroscopic events. Link to comment Share on other sites More sharing options...
[Tycho?] Posted January 25, 2005 Share Posted January 25, 2005 Maybe I missed the point, but wasn't the superposition of the cat simply reffering to the impossibility of predicting the outcome? When you open the box, the cat will be dead or alive, possibly dead for some time. But even if the cat is dead, you have no way of knowing the state of the cat unti the box is open and the cat is observed. Link to comment Share on other sites More sharing options...
Mart Posted January 25, 2005 Author Share Posted January 25, 2005 '']you have no way of knowing the state of the cat unti the box is open and the cat is observed. Agreed. But to me that suggests a difference between knowing the state of the cat and what state the cat is actually in (irrespective of our knowledge). Now, it may be the case that for quantum events there is no actual until there is knowing but does this apply to cats? Link to comment Share on other sites More sharing options...
Ophiolite Posted January 25, 2005 Share Posted January 25, 2005 I think not - well, not exactly. It is the act of opening the box and observing the contents which collapse the associated waveforms. I'm with ed84c on this, however, the cat can collapse its own waveform through self observation. I've discussed this with my own cat and she assures me she would notice if she were dead! (Did Schroedinger choose a cat rather than a dog or rabbit because of their nine lives? This would allow the experiment to be repeated several times with the same cat.) Link to comment Share on other sites More sharing options...
ecoli Posted January 25, 2005 Share Posted January 25, 2005 Ahh...but does your cat understand Quantum Mechanics? Link to comment Share on other sites More sharing options...
JaKiri Posted January 25, 2005 Share Posted January 25, 2005 I think not - well, not exactly. It is the act of opening the box and observing the contents which collapse the associated waveforms. I'm with ed84c on this, however, the cat can collapse its own waveform through self observation. I've discussed this with my own cat and she assures me she would notice if she were dead! The cat can do what it likes, the superposition still exists from our point of view. Remember, folks, that observing is any method of discovering whether the cat is living or dead. Find the center of mass of the box, shake it a bit, call in a psychic. These all count as 'observing' just as much as opening the box. Link to comment Share on other sites More sharing options...
Mart Posted January 26, 2005 Author Share Posted January 26, 2005 The cat can do what it likes' date=' the superposition still exists from our point of view.[/quote'] So superposition exists from our point of view? Would you say that this means that it is not a property of quantum particles and they can do what they like? Link to comment Share on other sites More sharing options...
[Tycho?] Posted January 26, 2005 Share Posted January 26, 2005 The cat can do what it likes' date=' the superposition still exists from our point of view. Remember, folks, that observing is [i']any[/i] method of discovering whether the cat is living or dead. Find the center of mass of the box, shake it a bit, call in a psychic. These all count as 'observing' just as much as opening the box. Smelling decayin cat... Link to comment Share on other sites More sharing options...
Guest Denzel Posted January 26, 2005 Share Posted January 26, 2005 As I understand the story, Schroedinger made up this thought experiment to demonstrate to his peers just how ridiculous QM is. Schoedinger was more of a wave man and he disliked his equation being hijacked by the QM sect. He found QM unsettling and didn't like it at all. Indeed he said: I don't like it (Quantum Mech.), and I'm sorry I had anything to do with it. Link to comment Share on other sites More sharing options...
Ophiolite Posted January 26, 2005 Share Posted January 26, 2005 Ahh...but does your cat understand Quantum Mechanics?I'm uncertain. Link to comment Share on other sites More sharing options...
yummifruitbat Posted February 2, 2005 Share Posted February 2, 2005 So does the cat cease to be in a superposition of states after, say, a fortnight? You can thus just wait out quantum mechanics and beat Schrödinger with your box, which contains a dehydrated, starved and quite possibly somewhat mummified cat! Link to comment Share on other sites More sharing options...
mmalluck Posted February 2, 2005 Share Posted February 2, 2005 So does the cat cease to be in a superposition of states after, say, a fortnight? You can thus just wait out quantum mechanics and beat Schrödinger with your box, which contains a dehydrated, starved and quite possibly somewhat mummified cat! Unless, by some quark of quantum physics, your cat quantum-tunneled right out of the box, but you wouldn't know that until you opened or even lifted the box. Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted February 2, 2005 Share Posted February 2, 2005 What if you had two cats in the box, one male and one female. After, say, 10 minutes a decay device will trigger one of them dead in a way that won't effect the other. (Say it triggers a cyanide capsule to rupture in the stomach). So you have a live/dead cat and another live/dead cat. Can they interfere with each other? Assume there is enough food and water in the box/system and half the box was isolated/compartmented so the cats can't get to it because of a trap door than wasn't (quite) big enough. After a year the trap door is sealed and the isolation/compartment is saved and the remaining half is jettisoned into a black hole. When the isolation/compartment is opened could it contain any kittens? Link to comment Share on other sites More sharing options...
TimeTraveler Posted February 2, 2005 Share Posted February 2, 2005 Indeed he said: I don't like it (Quantum Mech.), and I'm sorry I had anything to do with it. I thought Einstein said that? Edit - nm, I looked it up your right. Link to comment Share on other sites More sharing options...
mmalluck Posted February 3, 2005 Share Posted February 3, 2005 I think we left out a state... "In fact, the mere act of opening the box will determine the state of the cat, although in this case there were three determinate states the cat could be in: these being Alive, Dead, and Bloody Furious." -- Schrodinger's Moggy explained (Terry Pratchett, Lords and Ladies) Link to comment Share on other sites More sharing options...
Gnieus Posted February 9, 2005 Share Posted February 9, 2005 In the quantum mechanical model nothing ever happens! The particle never has to decay. The probability just keeps getting closer and closer to one. There is nothing to force a real event to happen. This is very confusing because what we observe is always real events. We see the particle decay at some particular time. Maybe maths breaks down here as a model of the world. If one is two and somewhere else at the same time... maybe people have to chuck it. Maybe they already did? Maybe real probabilities are like springs under pressure, at 0.999999999999999999999999999999999999999999999999999 probability it just happens ... cause it's a real event, not a mathematical construct. Whatever, I don't like cats anyway... Link to comment Share on other sites More sharing options...
Guest Risen Posted February 11, 2005 Share Posted February 11, 2005 Schroedinger's bit is just a representation, it's debatable whether or not the cat s a qualified observer, which is what the theory requires; assuming, for the moment, the cat isn't a qo, then either you 'smell decaying cat, or you don't. Either one determines whether or not the cat is dead or alive; until you observe, the cat is neither and both. Link to comment Share on other sites More sharing options...
rakave Posted March 4, 2005 Share Posted March 4, 2005 A slight doubt here. Schrodinger's cat would be alive or dead but if you believe in half dead half alive thingi then that leads to multiverse theory right? Link to comment Share on other sites More sharing options...
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