Is Schrödinger's cat dead or alive?

[WarrenHuelsnitz]

Starts out as a very clear description of the intent of the Schrodinger's cat metaphor, but then he hedges at the end.  The paradox is understood - the system immediately decoheres and the cat is not in a superposition.  See this: 

[funwithmuel]

teacher: Do you understand superposition now?
Me: I am in a superposition of both I understand and what do you mean

[when-the-hrandomstuff]

YESYES YES YESYES
YES YES YES YES YES
YES YES YES YES YES
YES YES YES YES YES
YES YESYES YESYES

[stupormundi]

Total nonsense! Unless you observe something, YOU won't know. What's the point of this stupid argument?

[franceleeparis]

Nope, don’t buy this…. Everything exists in an infinite state and in order to measure it you have to take a specific point in time… which implies that you are measuring a specific state. As the state is constantly changing, you cannot be sure that your measurements are correct; only that they were correct at a specific time. Schroeder’s cat paradox is just an intellectual joke… if you cannot see something you cannot measure it. If you want to measure it, you have to observe it, but by observing it at a specific point in time you have changed its state and hence it’s characteristic. So by opening the box you have frozen the ‘cat’ in a particular state I.e dead or alive……that’s my take 🙂

[sophiehindle]

Doesnt the box become the observer once the lid is closed, as it measures the heat off the cat that is alive,

[ABitOfTheUniverse]

Of course the cat is an observer, you left out the Geiger counter and the hammer. The Geiger counter is also an observer. The observation process is even more minuscule though, it is the world outside of the atom that changes given a change in the condition of the atom.
It's really not a very complicated thing to understand now that we've had 100 years to make sense of it. It's still nonintuitive but so are a lot of concepts until their practical applications and implications are understood.

[sophiehindle]

Are twins born from the same egg and sperm quantum entangled?

[sophiehindle]

BOOKRIDING, but does the cat exist? As he needs to be obsered to exist

[jamestagge]

I understand the theory of superposition as pertains to sub-atomic particles but like Schroedinger, I do not see it applying to “composite entities”. Consider…as per Schroedinger, there is a cat in a box along with an emitter of a decaying radioactive material which gives off a particle every so often but at an unpredictable rate. There is then a collector which counts these particles which itself releases a hammer to break a vile of poison when a preset count is reached, releasing its contents into the box where it could affect the death of the cat. According to the proponents of this theory, the cat would be in superposition and both dead and alive at the same time (or neither dead nor alive at the same time as some contend) “until” someone opened the box to observe the cat when the wave form would collapse and the cat would be either alive or dead but not both. Far too many questions are begged by such a notion, some for which here, there is no opportunity to answer.
In an attempt to demonstrate the likely falsity of the theory of superposition as it applies to composite entities and thus its implications, I propose the following; The conditions of the Schroedinger’s cat thought experiment remain exactly the same but for the poison which would be replaced with an acid, the fumes of which would still be lethal to the cat, and a mechanism on the floor of the box which were the cat to lie/fall down, would cause the vile to tip over. When broken, its contents would kill the cat, spill onto the floor of the box and eat through to the outside. In this then, there would be no observer opening the box but rather a chain of interdependent events which would at their end, in effect, be reaching out to the observer after the fact. The acid leaking from the box would only be possible were the cat dead and only dead. That the mechanism would act to spill the acid on the floor “only” by means of the cat being dead and falling upon it and would not were it still alive, makes this clear. No dead cat, no leaking acid to alarm the observer that he might turn to observe. To illuminate further, that necessary for the Schroedinger version of this scheme is that there be no consequence of events of the cat’s state as either alive or dead or even potentially one or the other. The cat’s state as alive or dead is the end of the sequence of events contained within the box. In my version in which the cat’s state is nested within a line of other deterministic events, those subsequent to the cat’s state cannot be realized materially unless the cat were dead and only dead. The observer would not have looked at all but for the process having in a sense “reached out” to alert him to its presence. If as might be claimed that his observation of the dripping acid would cause the wave form to collapse and the condition of the acid dripping to manifest then how could it have been manifest already that it might capture his attention that he might turn to observe it, to then cause the wave form to collapse so that it could be dripping which it was in the first place? This makes no sense and defies the same brand or current of logic by which the experiment was initially defined. I would venture that if this cannot be resolved by the proponents of the superposition of particles, one then has to question the ability of composite entities to be in superposition, ever. So, we see that there is no wave form here and thus no superposition of the cat. A great deal of physics would fall away in the exposition of such an error with this aspect of superposition theory, not merely inviting alternative ontological possibilities but rather demanding their consideration. Silly notions of multi-verses, cyclical universe existing back infinitely and human perception as a component of the means of material existence would all be dispensed with, as they should.

[ThePinkus]

0:55 QM says the cat is both dead and alive because... it is known, Khaleesi.
In other terms, since obviously (sadly, but obviously) most of the people alive does not know QM, it is well possible that many of them think they know that QM says that some cats are dead and alive.
Only, QM doesn't.
The scenario is formalized in QM considering the tensor product of the space state of the two systems, which are considered in respect to two fixed observables, one on each of the systems, with two possible results for each of the observables.
One of the systems is prepared so that it has 50% chance to give each of the results for its chosen observable.
If the system is considered initially to be isolated, then it is represented as the superposition of the two eigenstates of the observable (i.e. those that corresponds to the results of the observable).
Then it is made to interact with the second system in such a way that the states of the chosen observables correlate perfectly.
Under the assumption/idealization that the two systems are, as a whole, isolated (which happens to be false for cats), the resulting state is a superposition of the states that are the tensor products of the eigenstates of the observables.
So far we have used QM to determine what is the formalization of the scenario we narrated.
Now, what QM tells us is determined by the application of Born's rule and we can phrase it something like this: if we observe the state of system 1 for the chosen observable, there's a 50-50 chance for each results; if we observe system 2 for the chosen observable, there's a 50-50 chance for each results; furthermore, if we combine the observations, then they are perfectly correlated.
If this was applicable to Schroedinger's cat (it isn't because cats are not isolated systems, but let's concede this idealization for the sake of argument), then we would be saying that opening the box we would have 50-50 chance that the cat is either dead or alive and that it is dead if and only if the decaying atom has triggered the killing mechanism.
This is what QM tells us, which is surprisingly unsurprising considering what we hear on this topic.
Where's the part where system 2 "is" both results? Nowhere... it seems QM doesn't tell us that.
"Oh, but the system 2 is in a superposition of the two states before we open the box!"
Only, no, it isn't.
Neither of the systems have a pure-state representation of their state after they have been correlated, as expected, as the pure state formalism applies to isolated systems and the required correlation negates their isolation from each other (exactly in the formal sense that their states are not separable as pure states).
The reduced states of the systems, which represents the possibility of observing each system separately, are statistical operators in a form, that of mixtures, that does not represents superpositions of the eigenstates of their chosen observables.
The superposition is in the tensor space of the systems and we have seen that it tells us the results are correlated.
The reduced state of each system does not tell us the system is in a superposition, which was the already unjustified motivation for telling the cat was both dead and alive.
And furthermore, if we were to consider the statistical structure of the mixture, we could see it is a classical statistical distribution on the eigenstates, which, if anything, tells us that the cat is NOT dead and alive, but either in the dead-state or in the alive-state because that is how we interpret such distributions when they behave classically.

[jacobthomas]

Since Schrodinger is long dead and any cat he had would now be over 50 years old: DEAD
Since the cat was imaginary and never existed in the first place: DEAD
Since this is a dead meme used to badly describe something that has nothing to do with torturing cats: DEAD
THE CAT IS DEAD!

[david_porthouse]

There's more than one way to travel faster than light, and quantum mechanics consists of a wave in one of the ways which is orthogonal to tachyonic Brownian motion in the other way. The latter goes into action when matter interacts with the electromagnetic field, leading to an outcome in which the cat is either alive or dead and never in a superposition. 30 seconds.

[huntertony]

 
have an idea what if you build i device that does the same thing as schrodingers cat but not use a cat you see what will happen if nones looking and if it truely has a def. state

[sophiehindle]

Doesnt the box itself become the observer, forcing the answer, as it measures the heat off a living cat, there for both boxes cannot have living cats

[TXD]

No it was dead and alive in the box but if somebody looks the law of physics tells us it csn only be dead or alive in one state only wen someone looks

[georgeschulte]

Could we also think of a Scratch Off Lottery Ticket? Until it is scratched off, it can be thought of as a WINNING ticket and a LOSING ticket, Once scratched off, one or the other is CONFIRMED

[shivam-tiwari]

So what does this mean? Only when light bounces off the cat and enters a human eye does the cat magically become either dead or alive? That doesn't make sense at all. What if the cat notices itself dying?

[_official]

Why are physicists still maintaining this non-paradox? :-D
The cat is an observer… come on...

[bristol]

On Schrodinger's cat- an imaginary life and mind, but a real cat

The cat illustrates the link between quantum (subjective, imaginary axis) and particle (objective, real axis) physics

The link is Schoedinger's equation (eqn (1) below). The i axis is the quantum or mental axis. Without this, there is no life. The real axis is that of the quantum's corresponding particle, the real body and brain of the cat.

Eqn (1) below is the link between quantum (mental) mechanics and real world physics (real axis). It also represents a Leibniz monad.

Leibniz's monad is the simplest possible entity, a substance without parts. In other words, a quantum. It is not the same as the term "monad" commonly used in mathematics. But although it is without parts, it is one aspect of a philosophical monistic dualism, the other aspect being a particle.

The basic assumption in this exploratory essay is that quanta are mental entities existing in imaginary space and time and
particles are real entities in real space and time. This is so if we accept Leibniz's universe as a dual-aspect monism.
Each real particle, if we use Leibniz's concept of the monad, has a corresponding quantum, orthogonal to the place and time
because imaginary not real) of the real component, but in itself not belonging to spacetime.

Consider Schrodinger's equation with Mind as a scalar quantum wave (the left hand side of the equation), which is the equation for Leibniz's monad :

- i * d(psi(r, t))/dt = H*psi(r, t) (1)

Here we have a particle acting in an electric field where dpsi(r, t)/dt acts as the differential slope of the mathematical
psi wave, and the Hamiltonian H is a real function containing a space-time gradient of psi and a potential energy.

What this says is that properties of the quantum are defined by the nature of real scalar psi (r, t).

Considera timeless holographic quantum pool table where the there is perhaps an additional
equation something like

- i (1-prob (r, t)) (2)

where the imaginary component disappears if prob(r, t) = 1 and r, t is the position of a hole deterministically located
(at fractal positions) to ensure a pre-established harmony. When the quantum drops through a hole it is no long purely
mental but part of the brain. Due to feedback from the brain, the equation for the particle quntum, like Schroedinger's cat,
will contain mixed real and imaginary components. And so on.


-Ever since Hume, science has imprisoned us in the dark cave of materialism and empiricism and needs to restore us to the