Everything after time T is determined

[skepticalbip]

I'm curious. Has anyone ever performed the Schrödinger's cat experiment for real? Has the effect actually been demonstrated?

Such an experiment really wouldn't illustrate anything meaningful. When the box was opened, the cat would be either dead or it would be alive. The thought experiment was intended as a criticism of the Copenhagen interpretation that quantum events remain indeterminate until they are observed. There is no way to know if the cat was in an indeterminate state before determining its state. Schrodinger assumed that the idea of a cat being both alive and dead would be a reasonable argument against the Copenhagen interpretation.

The question is, does a cat count as an observer? If it does, then it's collapsing it's own wave function. The box does nothing to conceal the result from an observer inside the box.

It's probably also, as Terry Pratchett pointed out, bloody furious.

Physicists working in QM have for quite a while now recognized that attempts to interpret and describe QM in a way understandable with our macro world experience just doesn't work. David Mermin's take is, “If I were forced to sum up in one sentence what the Copenhagen interpretation says to me, it would be 'Shut up and calculate!'”

That advice would likely save experimental physicists from a lot of painful cat scratches.

 

[bilby]

The question is, does a cat count as an observer? If it does, then it's collapsing it's own wave function. The box does nothing to conceal the result from an observer inside the box.

It's probably also, as Terry Pratchett pointed out, bloody furious.

Physicists working in QM have for quite a while now recognized that attempts to interpret and describe QM in a way understandable with our macro world experience just doesn't work. David Mermin's take is, “If I were forced to sum up in one sentence what the Copenhagen interpretation says to me, it would be 'Shut up and calculate!'”

That advice would likely save experimental physicists from a lot of painful cat scratches.

I completely agree with Mermin on that (in fact, I was about to say the same thing).

The maths works. The philosophy is for the birds. Unless the cat catches them.

 

[Speakpigeon]

The question is, does a cat count as an observer? If it does, then it's collapsing it's own wave function. The box does nothing to conceal the result from an observer inside the box.

I guess that's the crucial point. We could arrange a Schrödinger experiment with a QM physicist inside the box. He could record on a CD, for posterity, his impressions about being both dead and alive.

Maybe he could have a switch to prevent anyone from opening the box to avoid his two-state condition collapsing into the one state of being dead? What then? Would that work, do you think?
EB

 

[bilby]

The question is, does a cat count as an observer? If it does, then it's collapsing it's own wave function. The box does nothing to conceal the result from an observer inside the box.

I guess that's the crucial point. We could arrange a Schrödinger experiment with a QM physicist inside the box. He could record on a CD, for posterity, his impressions about being both dead and alive.

Maybe he could have a switch to prevent anyone from opening the box to avoid his two-state condition collapsing into the one state of being dead? What then? Would that work, do you think?
EB

I seem to recall that one of Terry Pratchett's wizards decided to achieve immortality by building a Death proof box - if Death was unable to reach him, he figured he would be immortal.

It was just as he realised the vital importance of air-holes in a venture of this kind, that a voice beside him said 'DARK IN HERE, ISN'T IT?'

 

[steve_bank]

There a4e models and there are interpretaions.

QM models are routinely used to daily designing things like trasisyors and kasers.

Speculation is just that. In general terms speculative QM has become pop silence. Plot devices for scifi.

Whether something exists if I do not see or measure it is more scifi to me.

Terms like 'collapsing the wave function' can be misleading. It sounds more esoteric than it is.

A wave function is a probability distribution function. In a gas laser, a rectangular potential well, integrating the WF in a small dxdydz yields the probability of a photon being present in the volume.

Imagine flipping a coin in a dark room. At any time index there is a probability of position and orientation in space. Flash a light briefly and the actual state is measured or quantified at a time index. You can say before the light the states are undetermined, we do not see them but they exist. When we look at it the current state manifests.

I see that as the same as measuring an atomic state. Atoms are continually in flux. A quantum scale measurement is an interaction between object and measurement apparatus. The act of measure ring creates or manifests a state.

When the coin hits the floor and stabilizes the WF has collapsed into a measureable physical state, but that is semantics. It is simply a measurement. The floor forces a heads or tails state.

 

[DBT]

Unless the passing of time is an illusion of the mind, and block time the state of the universe....

 

[Bearded One]

Quantum mechanics implies that we cannot know the eventual outcome but relativity implies that the outcome has already happened. So, to us it's indeterminate but to the Universe at large the uncertainties have already been resolved and the outcome is now static. We just can't observe it.

Our language, and brains, are not equipped to handle such concepts. What do we call the amalgamation of all time?

 

[skepticalbip]

Quantum mechanics implies that we cannot know the eventual outcome but relativity implies that the outcome has already happened. So, to us it's indeterminate but to the Universe at large the uncertainties have already been resolved and the outcome is now static. We just can't observe it.

Our language, and brains, are not equipped to handle such concepts. What do we call the amalgamation of all time?

My understanding is that uncle Albert made a distinction between time and the idea of past, present, and future. He saw time as a dimension but that "...the distinction between past, present, and future is only a stubbornly persistent illusion."

 

[Gun Nut]

What do we call the amalgamation of all time?

the sum of all time is zero.

History (-1) + Now (0) + Future (+1) = 0

Therefore, we may call the amalgamation of all time, "nothing".... or maybe more correctly, "nowhen".

 

[Speakpigeon]

Quantum mechanics implies that we cannot know the eventual outcome but relativity implies that the outcome has already happened. So, to us it's indeterminate but to the Universe at large the uncertainties have already been resolved and the outcome is now static. We just can't observe it.

Our language, and brains, are not equipped to handle such concepts. What do we call the amalgamation of all time?

What remains, however, is that life happens and animals thrive and species with a nervous system can observe reality, model it and plan ahead of it and be successful to a large extent. I'm still alive after decades even though I have a very limited perception of my environment. Science can predict the future outcome of highly complex physical experiments. Modern civilisation works (at least for the few years to come). So the nature of reality has to be compatible with that situation. The nature of reality has to be compatible with us having memories of past events and us being able to predict accurately the future outcome of our decisions. Surely, the Schrödinger cat could tell if he was still alive.
EB

 

[steve_bank]

https://www.youtube.com/watch?v=8NPJ6GMXM3E

Anybody see an out of place English telephone booth?

 

[rousseau]

...
(Note: I'm assuming that "time T" in the OP is a reference to the beginning of time, to T=0.)

We may never know. Seems rousseau has fled the scene.

Take any time since the inception of the universe - the conditions of the universe at that time determine the ensuing conditions.

 

[Treedbear]

...
(Note: I'm assuming that "time T" in the OP is a reference to the beginning of time, to T=0.)

We may never know. Seems rousseau has fled the scene.

Take any time since the inception of the universe - the conditions of the universe at that time determine the ensuing conditions.

There might be a problem there. Einstein developed the theory of relativity in order to deal with the issue of simultaneity. His conclusion is that there is no absolute reference. It depends on the individual relativistic frame. It only acquires meaning when they are causally connected. Such as at the big bang singularity. Therefore when you use any subsequent moment in time as the reference for T=0 it doesn't refer to everything. Or perhaps anything, since everything is in a unique relativistic frame to some degree. Especially things that are "happening". So it's no good to specify things that are within one common relativistic frame. Although maybe entangled particles can be simultaneous. Maybe that's the only case where it's true. But this has nothing to do with free will as mentioned in the OP. Anyway. It's Friday after work after two cold beers. That's what I got for ya.

 

[rousseau]

Take any time since the inception of the universe - the conditions of the universe at that time determine the ensuing conditions.

There might be a problem there. Einstein developed the theory of relativity in order to deal with the issue of simultaneity. His conclusion is that there is no absolute reference. It depends on the individual relativistic frame. It only acquires meaning when they are causally connected. Such as at the big bang singularity. Therefore when you use any subsequent moment in time as the reference for T=0 it doesn't refer to everything. Or perhaps anything, since everything is in a unique relativistic frame to some degree. Especially things that are "happening". So it's no good to specify things that are within one common relativistic frame. Although maybe entangled particles can be simultaneous. Maybe that's the only case where it's true. But this has nothing to do with free will as mentioned in the OP. Anyway. It's Friday after work after two cold beers. That's what I got for ya.

Einstein's relativity involved how to make calculations between relative objects, no? At any given time in the history of the universe the objects still exist at the same point, but to make calculations between them involving time, you'd need to take into account their relative position.

So overall the universe would provide the scope, natural law provides the framework, and within is what evolves.

 

[bilby]

Take any time since the inception of the universe - the conditions of the universe at that time determine the ensuing conditions.

There might be a problem there. Einstein developed the theory of relativity in order to deal with the issue of simultaneity. His conclusion is that there is no absolute reference. It depends on the individual relativistic frame. It only acquires meaning when they are causally connected. Such as at the big bang singularity. Therefore when you use any subsequent moment in time as the reference for T=0 it doesn't refer to everything. Or perhaps anything, since everything is in a unique relativistic frame to some degree. Especially things that are "happening". So it's no good to specify things that are within one common relativistic frame. Although maybe entangled particles can be simultaneous. Maybe that's the only case where it's true. But this has nothing to do with free will as mentioned in the OP. Anyway. It's Friday after work after two cold beers. That's what I got for ya.

Einstein's relativity involved how to make calculations between relative objects, no? At any given time in the history of the universe the objects still exist at the same point, but to make calculations between them involving time, you'd need to take into account their relative position.

So overall the universe would provide the scope, natural law provides the framework, and within is what evolves.

There's no such thing as a given time in the history of the universe.

If you pick an arbitrary reference frame, and observe two events, A and B, then observers in some other reference frames will disagree with you about whether A occurred before or after B; And according to Einstein, there's no reason to prefer one observation over another.

If you define T=0 as the time that you read this, and measure events only in your personal reference frame, then if you declare that the state of the universe as observed from your reference frame at T=0 determines all future events as defined by your reference frame, then you are claiming that from some other reference frames, events will be determined by causes that occur in their future.

You might put that down as just a weird result that applies only to observers in extreme circumstances; But to do so is to ignore that all reference frames are equal. To an observer who you see travelling at close to c, it is you who is in extreme circumstances. So your claim that A preceeds B is one that he can dismiss as weirdness caused by your velocity.

A non-local reference frame, in which you can take an instantaneous snapshot of the entire universe is prohibited; It requires that your information that builds the 'snapshot' travels faster than c.

You could get around this if you accept the Big Bang Theory, by declaring T=0 at the very beginning of the universe, when everything was in the same place, and therefore in a single reference frame; But at that point in time, you are looking at a singularity, and predicting its future requires division by zero.

Worse still, in such a small universe, quantum effects dominate, so you are left trying to use relativity to understand a quantum system - something we have yet to be able to do.

If you do come up with a workable quantum relativity, be sure to buy me a beer with your Nobel prize money.

 

[rousseau]

Einstein's relativity involved how to make calculations between relative objects, no? At any given time in the history of the universe the objects still exist at the same point, but to make calculations between them involving time, you'd need to take into account their relative position.

So overall the universe would provide the scope, natural law provides the framework, and within is what evolves.

There's no such thing as a given time in the history of the universe.

If you pick an arbitrary reference frame, and observe two events, A and B, then observers in some other reference frames will disagree with you about whether A occurred before or after B; And according to Einstein, there's no reason to prefer one observation over another.

If you define T=0 as the time that you read this, and measure events only in your personal reference frame, then if you declare that the state of the universe as observed from your reference frame at T=0 determines all future events as defined by your reference frame, then you are claiming that from some other reference frames, events will be determined by causes that occur in their future.

You might put that down as just a weird result that applies only to observers in extreme circumstances; But to do so is to ignore that all reference frames are equal. To an observer who you see travelling at close to c, it is you who is in extreme circumstances. So your claim that A preceeds B is one that he can dismiss as weirdness caused by your velocity.

A non-local reference frame, in which you can take an instantaneous snapshot of the entire universe is prohibited; It requires that your information that builds the 'snapshot' travels faster than c.

You could get around this if you accept the Big Bang Theory, by declaring T=0 at the very beginning of the universe, when everything was in the same place, and therefore in a single reference frame; But at that point in time, you are looking at a singularity, and predicting its future requires division by zero.

Worse still, in such a small universe, quantum effects dominate, so you are left trying to use relativity to understand a quantum system - something we have yet to be able to do.

If you do come up with a workable quantum relativity, be sure to buy me a beer with your Nobel prize money.

Right, but that time is just a construct to make calculations between different objects, no?

If two objects are 10 light-years away they still exist simultaneously. But when we want to reference them via a calculation relativity needs to be taken into account.

I'm not talking what can be calculated with t, mathematically, I'm talking the material conditions at any point in the universe.

 

[skepticalbip]

Take any time since the inception of the universe - the conditions of the universe at that time determine the ensuing conditions.

There might be a problem there. Einstein developed the theory of relativity in order to deal with the issue of simultaneity. His conclusion is that there is no absolute reference. It depends on the individual relativistic frame. It only acquires meaning when they are causally connected. Such as at the big bang singularity. Therefore when you use any subsequent moment in time as the reference for T=0 it doesn't refer to everything. Or perhaps anything, since everything is in a unique relativistic frame to some degree. Especially things that are "happening". So it's no good to specify things that are within one common relativistic frame. Although maybe entangled particles can be simultaneous. Maybe that's the only case where it's true. But this has nothing to do with free will as mentioned in the OP. Anyway. It's Friday after work after two cold beers. That's what I got for ya.

Einstein's relativity involved how to make calculations between relative objects, no?

Relativity certainly allows us to 'make calculations between relative objects' but relativity is more a model or theory of gravitation that describes the universe.

I think maybe you are thinking of special relativity not general relativity. Special relativity deals only with an 'imaginary' universe where there is no mass, gravity, or acceleration, only objects moving at constant velocity relative to each other but not interacting gravitationally. General relativity addresses gravity, space, time, and the real universe.

 

[steve_bank]

Everything before time t is history.

 

[Jolly_Penguin]

No. Google Laplaces demon for more.

I read this as "google lapdances" ... My mind is poisoned this morning.