Measurement Rules Quantum Universe

[zonde]

obviously there is reality when no observed

Sure, reality is there when not observed. This is assumption that is hardwired into our brains by evolution and it is not relaxed in science.
Well, of course you can say that you don't take it for granted if you are philosopher or if you want to sound smarter than you actually are.

 

[zonde]

there's no reason the universe can't observe itself - by observe, we just mean "measure". A detector can be an observer, or even a gas molecule. No "consciousness" required

Is this philosophy or physics?

 

[e.bar.goum]

Is this philosophy or physics?

Well, interpretations of quantum mechanics can go either way, right?

 

[zonde]

Well, interpretations of quantum mechanics can go either way, right?

Yes, and this is disturbing.

 

[bhobba]

Is this philosophy or physics?

Its physics.

The modern theory of decoherence has pretty much settled the issue - observation, measurement, call it what you like, is interaction. A few issues remain - but that part is pretty certain.

Thanks
Bill

 

[StevieTNZ]

No reply from Andrew, yet. I do hope he does respond.

 

[meBigGuy]

It seems, since we can describe and produce systems in which we can mathematically represent the state of a system before and after observation/interaction/measurement, that therefore something exists in a real sense just before the measurement/*/. That seems obvious (to ignorant me). Is QM just saying that, even though you can describe its supposed characteristics mathematically, you can't prove something actually exists? Is the math just an equation that turns out to be consistent with what happens after measurement/*, but is in no sense representative of something real or proof there is something real before measurement/*/?

It feels like the math proves there is a reality that is measured/*/ to create an effect, but says nothing about its nature. To say there was "nothing" before measurement seems a stretch. As bhobba said, there is interaction. Can one interact with nothing?

We can have something real that creates a QM system. The QM system is not real until we measure it? I guess I'm lost.

 

[bhobba]

Is QM just saying that, even though you can describe its supposed characteristics mathematically, you can't prove something actually exists?

I am with Victor Stenger on this:
http://www.azquotes.com/quote/565770

QM describes what kicks back (ie observations). But the object that allows us to make probabilistic predictions about that, the state, doesn't. Just my view - different interpretations have different takes.

Thanks
Bill

 

[meBigGuy]

We can create a QM system with a defined state out of real objects, but, once we do that, those objects no longer exist? I can understand that QM is saying nothing about the nature of the system beyond what will happen when it is measured/*/, but how can that be interpreted as not existing?

 

[bhobba]

We can create a QM system with a defined state out of real objects, but, once we do that, those objects no longer exist?

You are getting confused.

In QM the real things are observations. The state helps us predict the probability of those observations.

Thanks
Bill

 

[meBigGuy]

I don't think I am confused. I think people are being loose and fast with their definitions.
For example, you stated

observation, measurement, call it what you like, is interaction.

Which implies there is something that is being interacted with as it is measured.

I fully understand that IN QM the real things are the observations, and that, currently, QM does not speak to the nature what exists or doesn't exist prior to measurement/*/ other than providing the theory for a mathematical representation of what might happen when that measurement/*/ occurs.

But, the original article stated that there was no existence until there was measurement/*/. I'm just saying "that's not QM", and its not a very good interpretation either.

 

[rootone]

obviously there is reality when no observed

Yeah, I am pretty sure that trees fall down, even if nobody is there with a video camera to record the event.

 

[bhobba]

Which implies there is something that is being interacted with as it is measured.

It does not follow that something is real.

But, the original article stated that there was no existence until there was measurement/*/. I'm just saying "that's not QM", and its not a very good interpretation either.

If it said that its wrong - QM is silent on the issue.

Thanks
Bill

 

[meBigGuy]

It does not follow that something is real.

If by this you mean that currently QM does not imply/indicate/suggest that something is real, then I understand. I was going beyond QM saying something must exist, but that is not a supportable viewpoint in this QM forum (as should be). Saying it does not exist is likewise not supportable.

 

[StevieTNZ]

Yeah, I am pretty sure that trees fall down, even if nobody is there with a video camera to record the event.

The tree would be in a superposition of falling down/remaining standing, despite interacting (entangling) with the environment which is technically also in a quantum superposition.

 

[rootone]

But then what is happening if an explorer discovers a new island and observes trees which have fallen down due to maybe a hurricane.
The observer did not personally encounter the hurricane, but the blown down trees indicate that a hurricane happened.