Quantum Cat

[Dark Photon]

Hello Physics Fans.

 

now heres a question i hope someone could enlighten me.

 

the quantum cat expirenment* says that by observing the event, we are changing it. we are forcing the cat out of its super position. now we do this when we observe it. but what level of intelegance forces it out of superpostion. shouldnt the can be able to observe? if we picked out our individual atoms we will get fine atomic dust which would have never been alive. so we are actually just a gathering of moving particles. these partlces are already there in the experiment box so what is different? and is this only from out point of observation. any awnsers will be gratfully appreciated.

 

 

 

*Schrödinger's cat is a famous illustration of the principle in quantum theory of superposition, 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 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.

[ydoaPs]

i'm not quite sure what your question is. if your question is if particles interacting with each other constitues observation, then the answer is yes.

[Connor]

I think the schrödinger's cat example has more to do with a certain environment having communication or influence with another. From the point of view of outside the box, the cat's condition is indeterminate, but as soon as information flows between them the cat's condition is forced into a definate state.

 

I don't really have a great understanding of this either, but that's how I think of it.

[Dark Photon]

isnt there a quantum physicist around...

[ydoaPs]

not atm. there should be one sometime

 

edit:what is your level of maths?

[Dark Photon]

erm..... im 14, and im in high school/secondary school

[ydoaPs]

14 eh? i don't think you would understand the maths involved.

 

what is your specific question about it?

[5614]

He is asking what level of consciousness is required to break superposition. And it is a very complex question.

 

Taking the cat in a box example, surely the cat can decide for itself whether it is alive or dead, does that count as a conscious observation which breaks the superposition?

 

How about if we replace the cat with a human, the human would surely count as a conscious being who could bring himself out of superposition.

 

Assuming a radioactive trigger for the cat in the box, we could say that as soon as the Geiger counter even "looks" for the radioactive decay that the radioactive atom has been forced into one state or the other, ie. decaying or not.

 

Look at it a different way, when you observe the box you know whether the cat is dead or not. But the physicist in the next room doesn't know, to him you and the cat are both in a superposition. If you announce it to the whole building you are in then the outside world (out of the building) still don't know, to them you, the cat and the whole building is in a superposition. This could go on forever.

 

As by definition "the universe" includes everything there can be no 'outside' observer who collapses all wavefunctions. Some say that we are the conscious observers who have caused all wavefunctions to collapse... but then just because I know what state something is in, doesn't mean you do, so I just join part of the superposition. You'd need an infinite amount of conscious beings to bring everything out of superposition. The "solution" is as puzzling as the puzzle it is meant to solve.

 

It's a very interesting issue.

[Dark Photon]

what he said

[ydoaPs]

counsciousness is not needed at all. any interaction counts as observation. that is why the moon says in orbit even if no one is looking at it.

[Rakdos]

I always thought that the purpose of this idea was to make it easier for people to understand the idea of superpostion?

[Dark Photon]

it makes it quite hard.

 

beasically does a tree fall if no ones there to hear it? superpostion

[Klaynos]

it makes it quite hard.

 

beasically does a tree fall if no ones there to hear it? superpostion

 

Yes a tree does make a sound, if it doesn't then physics is not the same in all reference frames and we're screwed.

 

superposition is a relative thing, something is in a superposition state because you don't know what it is, someone else might know but you don't you need to measure the system to know what state it's in if you don't measure it you don't know.

 

In the case of teh cat if someone opens the door and sees the cat they are measuring it's aliveness, if they then halt the experiment (remove teh trigger), you still don't know the state of teh cat so it's still in a superposition state for you, but for the other person it isn't. Opening the door yourself will remove the superposition state. If the first person does not remove the trigger and sees the cat is still alive and then closes the door then the cat returns to a superposition state for him...

[BhavinB]

Actually, what you ask is a very complicated question that is still the topic of research. In research, the topic is called "quantum measurement" and many theorists are looking into a generalized Schroedinger Equation.

 

In this scheme the measuring device has an interaction with the general SE such that it collapses its waveform.

 

So really, its not a trivial question. In fact, you should feel proud knowing that most people who take QM don't question that property at all (myself included).

[swansont]

I always thought that the purpose of this idea was to make it easier for people to understand the idea of superpostion?

 

 

I thought it was to demonstrate that the pinciples of QM appear ridiculous when applied to macroscopic events. People don't think of a cat as being in a superposition of "alive" and "dead."

[Dark Photon]

so lets see.. if i open the box its no longer in superposition for me. but it is in super position for the man next door...

 

 

nice one thanks people

[Dark Photon]

this forums pretty useful

[Specusci]

"maths", lol, I'm only 16 and I'm pretty sure its "mathematics", and not just "maths"

 

IE, "You do not understand the mathematics of it", rather then, "You do not understand the maths of it"

 

Anyways, I think the real question is, at what point do these atomic interactions become complex enough to become intelligence? Can any interaction be a viable observer?

 

I say Humans and similar intelligences shouldn't be the only ones who can access/influence the behaviour of Quantum Mechanics. To me, it just seems so dangerously primitive a concept.

[ydoaPs]

you may notice that "maths" is far shorter than "mathEMATICs"

[Klaynos]

"maths"' date=' lol, I'm only 16 and I'm pretty sure its "mathematics", and not just "maths"

 

IE, "You do not understand the mathematics of it", rather then, "You do not understand the maths of it"

 

Anyways, I think the real question is, at what point do these atomic interactions become complex enough to become intelligence? Can any interaction be a viable observer?

 

I say Humans and similar intelligences shouldn't be the only ones who can access/influence the behaviour of Quantum Mechanics. To me, it just seems so dangerously primitive a concept.[/quote']

 

It's a relative and local thing, whether something is in a superposition state depends on your observation method, saying that an electron has been altered in some way so it has been observed does not in anyway change whether you know which of the states the system is in.

[ydoaPs]

Anyways' date=' I think the real question is, at what point do these atomic interactions become complex enough to become intelligence? Can any interaction be a viable observer?

 

I say Humans and similar intelligences shouldn't be the only ones who can access/influence the behaviour of Quantum Mechanics. To me, it just seems so dangerously primitive a concept.[/quote']people get too caught up on the term "observer." any interaction counts as an observation. how do you think we observe? usu. by bouncing photons off things and thus interacting with them.

[Klaynos]

very often: To observe = To measure....

[swansont]

"maths"' date=' lol, I'm only 16 and I'm pretty sure its "mathematics", and not just "maths"

[/quote']

 

Perhaps where you live, but this whole www thing is a big phenomenon. World-wide, even.

 

(Try not to react too strongly if you see e.g. "color" spelled "colour.")

[Klaynos]

(Try not to react too strongly if you see e.g. "color" spelled "colour.")

 

 

It really annoys me when people comment on colour being spelt correctly....

 

And maths/math is a shortening of mathematics that everyone I've met on or offline no matter their country or launguage of orgin has used, would be interested to know where Specusci is from :\

[Dark Photon]

interesting responses.

 

i think we should move on from the subject of the validity of the work "math"