Possibility, knowledge (information), and quantum mechanics

[Dimebag]

Is there a relationship between knowledge and possibility? I.e. the more knowledge you have of a system the less probable certain possibilities become,and as you increase the amount of knowledge about a system you are narrowing down the likelihood of any possibilities other than a single one. If knowledge were complete, possibility of anything but a single option would be 0. Is this why quantum mechanics must deal with possibilities; because of a lack of knowledge only possibilities can be used usefully.

In relation to quantum mechanics, could this also mean that possibilities are dealt with not because the properties of the phenomena in question are possibilities in nature but because of our limitation of knowledge of the system? If this were the case, then considering all possibilities as happening simultaneously until we observe them would only be a way of viewing our uncertainty of the system, not necessarily the nature of the system itself, would it not? The idea of probabilities is a useful way of coming to terms with our uncertainty, but should our lack of knowledge of the system curse the system to remain in a state of probability?

I am probably completely wrong here, but it was just a thought.

[Thundril]

The nice thing about probability theory is that it makes so few assumptions.
For example, imagine a unverse comprising a trillion flat discs, and a condition that a side of a disc may be either white or black; then assuming nothing creates a preference for black over white, or vice versa, there will probably be about half a trillion white faces and half a trillion black faces. (it is not likely that there will be exactly half of each, but very probable that there will be very nearly half a trillion each.)
That is just how it would be, in that universe, precisely because there is no reason for it to be otherwise. It has nothing to do with any conscious mind knowing or thinking anything about it.
Our human estimates of probability, OTOH, are very dependent on our state of knowledge. It is the failure to distinguish between these two kinds of probability (call them objective and subjective, maybe?) that leads to a lot of confusion in the framing of questions about probability.
Even quantum physicists are not immune from this confusion.
The uncertainty described by Heisenberg's Uncertainty Principle is a property of the particles themselves. The limit of our capacity to know is a result, not a cause, of the uncertainty in the sub-atomic world.

[Notvacka]

The limit of our capacity to know is a result, not a cause, of the uncertainty in the sub-atomic world.

Interestingly, time has no arrow in quantum mechanics. The cause might as well depend upon the effect as the other way around.

In quantum mechanics, as in every day life, probability only exists in the absence of certainty. When you look into the box, then you find out if the cat is alive or dead. And after the fact the "probability" is always 100 percent either way. But since "after" can be substituted with "before" on a quantum level, the "probability" is always 100 percent. Which makes quantum mechanics agree perfectly with Eintstein's theory of relativity, by the way.

Or to put it simply: que sera sera.

[Bernard]

How dependable is certainty? If the universe is primarily mechanistic by nature then certainty is very reliable. But I don't think the universe is primarily mechanistic. Quantum mechanics, or any other sort of mechanics, appears to me to be a function, but not the primary function.

[Thundril]

The limit of our capacity to know is a result, not a cause, of the uncertainty in the sub-atomic world.

Interestingly, time has no arrow in quantum mechanics. The cause might as well depend upon the effect as the other way around.

I

Interesting indeed, Notvacka!
Do you reckon the reversible arrow of time is more than a theoretical device, on scales larger than the sub-atomic? For example, do you think the idealism/materialism argument (whether consciousness creates reality or vice-versa) is equally valid either way round, on macro-scale? I'm thinking of the fact that we can know the past but not the future, so there seems to be some fundamental difference between the two.

[Notvacka]

The limit of our capacity to know is a result, not a cause, of the uncertainty in the sub-atomic world.

Interestingly, time has no arrow in quantum mechanics. The cause might as well depend upon the effect as the other way around.

Interesting indeed, Notvacka!
Do you reckon the reversible arrow of time is more than a theoretical device, on scales larger than the sub-atomic? For example, do you think the idealism/materialism argument (whether consciousness creates reality or vice-versa) is equally valid either way round, on macro-scale? I'm thinking of the fact that we can know the past but not the future, so there seems to be some fundamental difference between the two.

We can't know either past or future. What we have are records of the former and predictions of the latter, but any actual knowledge is here and now. As we knew the past when we were there, we will know the future when we get there.

I think that if you want to take the randomness of quantum mechanics into account on scales larger than the sub-atomic, then you have to take the reversible arrow of time along with it. And if you do, what you get is a determined universe, just like you get from relativity theory. This is my humble contribution to our understanding of physics.

My point is that whether we determine reality by observing it, or reality is determined in itself, it's still determined. Contrary to popular belief, quantum mechanics does not contradict relativity theory in this regard. The common error is applying our larger scale perspective (where the distinction between past and future makes sense) on the sub-atomic level, where it makes no sense.

Neither theory supports anything but a deterministic view of the world. The many worlds interpretation of quantum mechanics fails to take the reversible arrow of time into account. On a larger scale, the present is determined by the past, while on a sub-atomic scale, it's equally determined by the future.

[attofishpi]

It is probable that we have already, or that we will in the future, evolve into a simulated reality system.

[Notvacka]

It is probable that we have already, or that we will in the future, evolve into a simulated reality system.

And is there any discernible difference between a simulated "reality system" and, well, a "reality system"?

[Thundril]

We can't know either past or future. What we have are records of the former and predictions of the latter, but any actual knowledge is here and now. As we knew the past when we were there, we will know the future when we get there.

I don't understand this statement, Notvacka. You seem to be suggesting that only 'absolute' knowledge is valid. But if that is accepted, we can't 'know' the present either. (See the endless, and endlessly tiresome, brain-in-jar, Matrix, etc scenarios.)
Outside of such uselessness, we have to accept slightly more sensible criteria for 'knowledge'. In which case, what I remember is knowledge if accurate, whereas what I expect isn't. Even if it turns out to be true when the time comes!

I think that if you want to take the randomness of quantum mechanics into account on scales larger than the sub-atomic, then you have to take the reversible arrow of time along with it.

Some people might like the idea of scaling up the 'randomness', (By which I suspect they mean the uncertainty, a very different beast) but even if we wanted to scale it up, we couldn't.
Heisenberg's Uncertainty Principle describes in precise mathematical terms the relationship between the limits of certainty existing between pairs of quantities. Eg position and momentum. The product of the uncertainties in position and momentum is always equal to or greater than one half of the reduced Planck constant ħ,

Planck's constant h = 6.626068 × 10^-34 m^2 kg / s
Reduced Planck's constant =h/2pi.
Note that term 10^-34. that's seriously tiny!
So, as you can see, this amount is far too small to have effects that would be apparent to unaided human senses. It's really there, though, in the nature itself, and isn't simply a function of our inaccuracies in measurement.

And if you do, what you get is a determined universe, just like you get from relativity theory. This is my humble contribution to our understanding of physics.

My point is that whether we determine reality by observing it, or reality is determined in itself, it's still determined. Contrary to popular belief, quantum mechanics does not contradict relativity theory in this regard. The common error is applying our larger scale perspective (where the distinction between past and future makes sense) on the sub-atomic level, where it makes no sense.

Neither theory supports anything but a deterministic view of the world. The many worlds interpretation of quantum mechanics fails to take the reversible arrow of time into account. On a larger scale, the present is determined by the past, while on a sub-atomic scale, it's equally determined by the future.

I think it's better to say that, on the sub-atomic scale, the theories (quantum and relativistic) ought to work equally well with the arrow of time reversed, and that some events have been observed in which this does seem to be the case.

I broadly agree about the determinism, Notvacka. At least in the sense that our ideas about 'free will' and so forth are themselves determined by forces outside of, and independent of, consciousness. Another subject where some people seem to think the concept of 'randomness' is relevant. (It's not!)
But I still consider effectively-true randomness is possible; which, as you say, does not fit with a reversible arrow of time. So the many-worlds scenario is workable.

[Notvacka]

We can't know either past or future. What we have are records of the former and predictions of the latter, but any actual knowledge is here and now. As we knew the past when we were there, we will know the future when we get there.

I don't understand this statement, Notvacka. You seem to be suggesting that only 'absolute' knowledge is valid. But if that is accepted, we can't 'know' the present either. (See the endless, and endlessly tiresome, brain-in-jar, Matrix, etc scenarios.)
Outside of such uselessness, we have to accept slightly more sensible criteria for 'knowledge'. In which case, what I remember is knowledge if accurate, whereas what I expect isn't. Even if it turns out to be true when the time comes!

Sorry. I admit that we do have knowledge of the past that we don't have of the future. (The knowledge being absolute or not doesn't matter.) What matters is that the distinction between past and future is anything but absolute.

But I still consider effectively-true randomness is possible; which, as you say, does not fit with a reversible arrow of time. So the many-worlds scenario is workable.

I must confess that I don't grasp what randomness, "effectively-true" or not, is supposed to mean other than uncertainty.

And please excuse me if it seems like I helplessly repeat myself:

An event is considered random when the outcome can't be predicted with any degree of certainty beforehand.

But any distinction between past and future is made by "now", which is always subjective and never the same.

Any particular moment of "now" must be as valid as any other. If the past is set, so must the future be.

In the four-dimensional space-time of relativity, nothing ever happens because the universe is static. In the multiverse of quantum mechanics, nothing in particular ever happens, because supposedly everything that could possibly happen does happen somewhere.

The notion of choice is meaningless to relativity, since the future is already formed and "out there". And the notion of choice is meaningless to the multiverse, because every outcome is supposedly realised somewhere "out there" anyway.

Now, my beef with the many-worlds scenario is that the universe splits up and multiplies indefinitely in the future, while we only have one past. From a quantum perspective, the universe should split up and multiply indefinitely in the past also.

Since we have one past only, it figures that we can only have one future as well. And that future must be determined at some point in time. Hence, the future is determined.

[attofishpi]

It is probable that we have already, or that we will in the future, evolve into a simulated reality system.

And is there any discernible difference between a simulated "reality system" and, well, a "reality system"?

How the f**k would i know?

[chaz wyman]

It is probable that we have already, or that we will in the future, evolve into a simulated reality system.

And is there any discernible difference between a simulated "reality system" and, well, a "reality system"?

How the f**k would i know?

How the fuck would anyone know, if the simulation were accurate?

[Thundril]

Sorry. I admit that we do have knowledge of the past that we don't have of the future. (The knowledge being absolute or not doesn't matter.) What matters is that the distinction between past and future is anything but absolute.

Agreed!

But I still consider effectively-true randomness is possible; which, as you say, does not fit with a reversible arrow of time. So the many-worlds scenario is workable.

I must confess that I don't grasp what randomness, "effectively-true" or not, is supposed to mean other than uncertainty.
And please excuse me if it seems like I helplessly repeat myself:
An event is considered random when the outcome can't be predicted with any degree of certainty beforehand.

Maybe I'm using the terms too loosely.
I think of 'random' as meaning undetermined-in-itself, irrespective of any consciousness that might or might not be around. And I think of 'uncertainty' as referring specifically to a state of mind with respect to apparently random events.
This is an unambiguously materialist approach, which eliminates the 'reversible arrow of time' with respect to knowledge..
Don't know if this distinction is technically correct, though. What do you think?

But any distinction between past and future is made by "now", which is always subjective and never the same.
Any particular moment of "now" must be as valid as any other. If the past is set, so must the future be.
In the four-dimensional space-time of relativity, nothing ever happens because the universe is static. In the multiverse of quantum mechanics, nothing in particular ever happens, because supposedly everything that could possibly happen does happen somewhere.
The notion of choice is meaningless to relativity, since the future is already formed and "out there". And the notion of choice is meaningless to the multiverse, because every outcome is supposedly realised somewhere "out there" anyway.

Now, my beef with the many-worlds scenario is that the universe splits up and multiplies indefinitely in the future, while we only have one past. From a quantum perspective, the universe should split up and multiply indefinitely in the past also.

Since we have one past only, it figures that we can only have one future as well. And that future must be determined at some point in time. Hence, the future is determined.

An alternative distinction can be made by considering 'now' as the edge of a phase-transion, analogous (very approximately) to the transition from liquid to solid. (The past is 'fixed', for any observing system, whilst the future is 'fluid').

[Notvacka]

Maybe I'm using the terms too loosely.
I think of 'random' as meaning undetermined-in-itself, irrespective of any consciousness that might or might not be around. And I think of 'uncertainty' as referring specifically to a state of mind with respect to apparently random events.
This is an unambiguously materialist approach, which eliminates the 'reversible arrow of time' with respect to knowledge..
Don't know if this distinction is technically correct, though. What do you think?

I think that your unambiguosly materialist approach works, if reality is defined as what can be measured. Since we can't measure beyond the limits of Heisenberg's uncertainty principle, reality is undetermined in itself in that sense. On the other hand, it seems reasonable to assume that reality actually extends and exists independently and beyond what we can measure. But that's of course in the realm of metaphysics.

An alternative distinction can be made by considering 'now' as the edge of a phase-transion, analogous (very approximately) to the transition from liquid to solid. (The past is 'fixed', for any observing system, whilst the future is 'fluid').

Yes. That works rather well as metaphor. "For any observing system" is what makes it troublesome if you want to consider your apporach "unambiguosly materialist". It seems to imply that without any observer "reality" woud remain fluid and unformed indefinitely, which doesn't make sense from a wholly materialist standpoint, I think.

[Thundril]

Maybe I'm using the terms too loosely.
I think of 'random' as meaning undetermined-in-itself, irrespective of any consciousness that might or might not be around. And I think of 'uncertainty' as referring specifically to a state of mind with respect to apparently random events.
This is an unambiguously materialist approach, which eliminates the 'reversible arrow of time' with respect to knowledge..
Don't know if this distinction is technically correct, though. What do you think?

I think that your unambiguosly materialist approach works, if reality is defined as what can be measured. Since we can't measure beyond the limits of Heisenberg's uncertainty principle, reality is undetermined in itself in that sense. On the other hand, it seems reasonable to assume that reality actually extends and exists independently and beyond what we can measure. But that's of course in the realm of metaphysics.

Yep! That drags me kickin an screamin into the realm of 'materialism is just as much a faith as (name yr poison)'!

An alternative distinction can be made by considering 'now' as the edge of a phase-transion, analogous (very approximately) to the transition from liquid to solid. (The past is 'fixed', for any observing system, whilst the future is 'fluid').

Yes. That works rather well as metaphor. "For any observing system" is what makes it troublesome if you want to consider your apporach "unambiguosly materialist". It seems to imply that without any observer "reality" woud remain fluid and unformed indefinitely, which doesn't make sense from a wholly materialist standpoint, I think.

Hmm. . . . (Rapid rethink.) 'Observing system', a phrase of habit, is problematic. I think of any 'measuring event' , whether conscious or not, as an 'observing system'. for example, a charged particle 'observes' and responds to another charged particle in its range of sensitivity. Not sure if that's scientifically kosher, or just my getout. Will have to read something by someone who actually knows some shit, and then get back to you. All best!