a timely question

[renormalised (Carl)]

Originally Posted by bojan

Errr.. is that so?

We define time as "something" that happens/elapses between two events, one happening at the "observed" object (particle) and "observer" (affected particle).

I think we need at least two particles (observer is the reference) to be able to measure time (to determine if the event associated with object happened before or after the event(s) happening on the observer.

The observer and the observed can be one and the same in Quantum Physics....we need to get away from this separation of the two as it would be expected in SR/GR or Classical Physics. Even in what we would call "reality" they can be one and the same.

An example, you exist. You know that you exist because you observe this to be the case. Therefore, you're both the observer (the one acknowledging your existence) and the observed (that which exists). You are self referential...in actual fact the Universe is self referential.

[renormalised (Carl)]

Originally Posted by CraigS

I notice that whilst questions about it are valid, answers clearly, may not be supportable in Science.

Definition of 'moot': of little or no practical value or meaning; purely academic !!

.. The only value or meaning it has, is what we associate with it.



Ok … so attempting to answer the question doesn't work …

… I'm going to become religious .. … and its all Brian's fault …
... (just kidding, Brian .. its not your fault .. and there's nothing wrong with religion .. )

Cheers

The questions are answerable, only that our science at present can't answer them because we still don't understand the fundamental physics behind it all. Not only that, but most scientists don't want to go there because they have no way of measuring anything, sticking it into pigeon holes and classifying it. This is precisely why the scientific method is limited and in some ways flawed. We may never know the answers unless we devise new tools or improve on those we've got.

[bojan]

Originally Posted by renormalised

The observer and the observed can be one and the same in Quantum Physics....we need to get away from this separation of the two as it would be expected in SR/GR or Classical Physics. Even in what we would call "reality" they can be one and the same.

An example, you exist. You know that you exist because you observe this to be the case. Therefore, you're both the observer (the one acknowledging your existence) and the observed (that which exists). You are self referential...in actual fact the Universe is self referential.

Yes, but accurate measurement is different issue.
You always need a reference (etalon) to compare with.
For example: 1kg mass used to be defined as a chunk of iridium, stored somewhere in Paris ..
http://en.wikipedia.org/wiki/Kilogram

And so on.

[CraigS]

Originally Posted by renormalised

An example, you exist. You know that you exist because you observe this to be the case. Therefore, you're both the observer (the one acknowledging your existence) and the observed (that which exists). You are self referential...in actual fact the Universe is self referential.

There was an episode of Star Trek: Enterprise where Archer was infected with parasites from another dimension. They stopped him from forming long term memories. When the doctor finally removed them, they disappeared in Archer's medical scans .. so by removing them in the present, they never existed in the past and Archer returned to normal .. despite being annihilated in the (infected) past !

Self-referentiality is all in the memories folks !
.. So the universe must have a memory ..

Cheers

[bojan]

Originally Posted by renormalised

...... We may never know the answers unless we devise new tools or improve on those we've got.

Now you are getting into philosophy (or even worse - into metaphysics..)
What became of you Carl ?

[CraigS]

Originally Posted by bojan

What became of you Carl ?

Cyclone Yasi !!

[bojan]

Originally Posted by CraigS

Cyclone Yasi !!

Must have been something of that magnitude....

[CraigS]

Carl chants in in the background in dulcet Gregorian tones ...

[renormalised (Carl)]

Originally Posted by bojan

Yes, but accurate measurement is different issue.
You always need a reference (etalon) to compare with.
For example: 1kg mass used to be defined as a chunk of iridium, stored somewhere in Paris ..
http://en.wikipedia.org/wiki/Kilogram

And so on.

Whoever said there was anything accurate about the measurements or that a reference outside of the system was needed. To what do we refer to when we observe the Universe?? Or the fact of our existence (both individually and as a whole w.r.t. the Universe as existing).

In reality, there can be no absolutely accurate measurements of anything, even mass. Mass is nothing more than the energy content of an object (good old E=mc^2) and is subject to the vagaries of the quantum world...on both a micro and macroscopic scale.

[renormalised (Carl)]

Originally Posted by bojan

Now you are getting into philosophy (or even worse - into metaphysics..)
What became of you Carl ?

No, I said we either need to invent new tools or improve on what we've got. Science as it stand (or to be more accurate, the scientific method) cannot answer all the questions it's posed, or even those it's tried to answer, because the tools it uses aren't up to scratch.

[renormalised (Carl)]

Originally Posted by CraigS

Self-referentiality is all in the memories folks !
.. So the universe must have a memory ..

Cheers

Who says it doesn't??. We couldn't prove it either way because we don't have the science to do so, at present. Therefore it gets pigeon holed into the "too hard" basket or into philosophy/metaphysics (as we like to call it).

[renormalised (Carl)]

Originally Posted by CraigS

Carl chants in in the background in dulcet Gregorian tones ...

No, I'm doing a Buddhist chant

[CraigS]

Originally Posted by renormalised

No, I said we either need to invent new tools or improve on what we've got. Science as it stand (or to be more accurate, the scientific method) cannot answer all the questions it's posed, or even those it's tried to answer, because the tools it uses aren't up to scratch.

Why is the method the problem ?

The 'tools' we've developed, (presumably), are GR/SR and QM .. Strings, Ms, etc. So there maybe some tools we are yet to develop .. I can see that ..
… but why would the process need over-hauling ? I'm not sure that its 'the scientific method' which attempts to answer anything .. humans attempt answers .. the process, (ie: method), is there to establish repeatability and provide predictions .. not answers.

( .. but Carl seems to have said that it does attempt answers ..??).

Cheers

[renormalised (Carl)]

Originally Posted by CraigS

Why is the method the problem ?

The 'tools' we've developed, (presumably), are GR/SR and QM .. Strings, Ms, etc. So there maybe some tools we are yet to develop .. I can see that ..
… but why would the process need over-hauling ? I'm not sure that its 'the scientific method' which attempts to answer anything .. humans attempt answers .. the process, (ie: method), is there to establish repeatability and provide predictions .. not answers.

( .. but Carl seems to have said that it does attempt answers ..??).

Cheers

The method is the problem because despite the fact it has developed a lot of very good tools for probing all these various questions, many of these tools (especially quantum physics) have come up against aspects of reality which they can't probe as they are because they're limited in what they can do...or have brought up new questions about processes they've discovered which they can't answer as they stand because of those same limitations. Mostly a limitation of knowledge on our part because we can't see past the limitations of the tools we use, at present. It's like trying to use a wrench to undo a wheel nut that's rusted onto a wheel when you have no rust killer to make the job a whole lot easier...or you don't know about rust killer to begin with. Tool may fit the nut but it can't do the job required of it because it lacks that something (rust killer) to free up the nut.

[Karls48 (Karl)]

Originally Posted by CraigS

Why is the method the problem ?

The 'tools' we've developed, (presumably), are GR/SR and QM .. Strings, Ms, etc. So there maybe some tools we are yet to develop .. I can see that ..
… but why would the process need over-hauling ? I'm not sure that its 'the scientific method' which attempts to answer anything .. humans attempt answers .. the process, (ie: method), is there to establish repeatability and provide predictions .. not answers.

( .. but Carl seems to have said that it does attempt answers ..??).

Cheers

I would use different example. Because today’s theories say that faster then light communications and travel is impossible no one will try to develop such.

[CraigS]

Originally Posted by Karls48

I would use different example. Because today’s theories say that faster then light communications and travel is impossible no one will try to develop such.

So what … we change the method that has highlighted the problems of travelling at these velocities and that overcomes the problems ??

.. I don't think so !!

Quantum leaps forward are still allowed for in science .. breakthroughs have always happened. The process has never inhibited these.

Sorry .. that one doesn't wash with me.

Cheers

[sjastro]

Here is a non maths version of the QM explanation as to why time is not an observable.

As Carl mentioned in a previous post one can define a quantum wavefunction as superimposed state containing all the possible outcomes for the observable.

Examples of observables are position, linear momentum, angular momentum, energy and spin. If the wavefunction is time independent the superimposed state does not change.
When a measurement is performed the wavefunction collapses and a measurement or observable is the outcome.
The same test can be performed over and over. The same superimposed state collapses each time to give an observable. From this you can calculate the average and standard deviation or variance of the measurements.

Now let's bring time into the picture. Suppose the wavefunction is now time dependent. The superimposed state now changes with time along with any of the observables.
To perform a measurement involving a time dependent function one would have to so at the same specific time for each measurement.

It's for this reason time is not an observable. If it was each different time measurement would correspond to a different collapsing wavefuction.

For example if a particle decays, it has an intial and final quantum state.
If time was observable, the first few measurements for say energy may correspond to the initial state, all others may be for the final state.
You can't mix the different states of superimposition.

There is however an important relationship between the energy difference in 2 different quantum states and the time taken to go from one state to another. If the energy difference is large the time interval is small and vice versa.

Regards

Steven

[CraigS]

Originally Posted by renormalised

The method is the problem because despite the fact it has developed a lot of very good tools for probing all these various questions, many of these tools (especially quantum physics) have come up against aspects of reality which they can't probe as they are because they're limited in what they can do...or have brought up new questions about processes they've discovered which they can't answer as they stand because of those same limitations. Mostly a limitation of knowledge on our part because we can't see past the limitations of the tools we use, at present.

Well I don't think as a general statement, this represents an accurate view of science 'thinkers' nor of human imagination.

If I can see that science tools have their limitations, anyone can !

I think I agree that we need more tools but the process doesn't necessarily inhibit the development of them. (I would say, it actually enhances it).

Can you provide an example of what you mean ?

Let me also say, that for any axiomatic system, there will always be things outside of that system, which cannot be proven from within that system. This itself has been proven. (Godel's Incompleteness theorems).

Axiomatic systems are difficult to avoid. The universe may be one of them.

This aspect, combined with human ingenuity and inquisitiveness, may actually be the driver for continued tools development (and human breakthroughs).

Cheers

[avandonk]

I see reality as an evolving entity that is just the product of all past interactions. Each collapse of the infinite wave functions that describe interacting waves is another tick in time for those wave functions. Time is part of the fabric of all these waves.

In order of appearance, energy, primordial H and He with a bit of Li, gravitational collapse of these leading to nucleosynthesis in stars and SN, chemical and physical interactions of heavier elements leading to even more complex interactions leading to planets and ultimately life.

Your existence is inextricably linked all the way back to structureless energy.

See not so difficult!

Time will end with the last interaction!

Or when you die whichever comes first.

Would the last observer please turn off the photon source.

Bert

[snas (Stuart)]

So Craig, if no one is there to observe it, does it exist?? Carl

I guess you could also say, if a quantum particle falls in a forest, does anybody hear?

If time only exists as an observable recordable experience then time cannot exist without an observer.
Brian

So would that make time a function of quantum physics?