Absolute and Relative Time

[Mike Helland]

the word relative as used by Everett in his thesis has nothing to do with relative as used in relativity.

And the word relative in relativity has nothing do with how Newton used the word.

Cool.

We have 3 unique uses of the word relative. No connection. Unrelated, you could say.

Sweet.

That's a wrap. I hope we all enjoyed ourselves.

 

[theprestige]

It's depressing that you're still trying to to do physics via natural language, rather than systems of formal logic.

Why do you still not think this is a mistake to be avoided?

 

[Mike Helland]

It's depressing

If someone on the internet says something that you don't agree with, rather than becoming depressed, you should just take a break. You earned it.

that you're still trying to to do physics via natural language, rather than systems of formal logic.

My position is that Everett's relative state formulation will probably be written with code in the near future.

A modern GPU is basically a supercomputer to anyone writing code in the 90's. It's baffling to read something from the 50's hinting at the power of "complex automata". Unfortunately, Everett died in the early 80's. Working on computer vision and hearing.

I think his contributions have yet to be fully appreciated, and it seems inevitable they will in this century.

But whatever, don't let that get you down. I'm an idiot.

 

[W.D.Clinger]

It's depressing that you're still trying to to do physics via natural language, rather than systems of formal logic.

Why do you still not think this is a mistake to be avoided?

My position is that Everett's relative state formulation will probably be written with code in the near future.

The semantics of code is defined via logic and mathematics.

The semantics of logic and mathematics is not defined via code.

There are good reasons for that. Those reasons go a long way toward explaining why physicists use mathematics when framing their theories, and code when calculating quantitative consequences of those theories.

 

[Mike Helland]

The semantics of code is defined via logic and mathematics.

The semantics of logic and mathematics is not defined via code.

There are good reasons for that. Those reasons go a long way toward explaining why physicists use mathematics when framing their theories, and code when calculating quantitative consequences of those theories.

Relative doesn't mean of a relational nature, and algorithms aren't math.

Got it.

 

[Cheetah]

You must understand what relative means in context. Everett has nothing to do with relative vs absolute time.
To me it seems that your confusion stems from no apparent understanding of SR.

 

[Mike Helland]

You must understand what relative means in context. Everett has nothing to do with relative vs absolute time.

p 7

Summarizing: There does not, in general, exist anything like a single
state for one subsystem of a composite system. Subsystems do not possess
states that are independent of the states of the remainder of the system, so
that the subsystem states are generally correlated with one another. One can
arbitrarily choose a state for one subsystem, and be led to the relative state
for the remainder. Thus we are faced with a fundamental relativity of states,
which is implied by the formalism of composite systems. It is meaningless to
ask the absolute state of a subsystem—one can only ask the state relative to
a given state of the remainder of the subsystem

p 8

Consider any measuring apparatus interacting with any object system. As
a result of the interaction the state of the measuring apparatus is no longer
capable of independent definition. It can be defined only relative to the state
of the object system.

(Emphasis his.)

 

[Cheetah]

Yes, see what I mean?

 

[Mike Helland]

Yes, see what I mean?

He's hammering the point that the observer and the object should be considered as part of the same system, not independent, not absolute, but fundamentally related.

He continues (emphasis mine):

"As models for observers we can, if we wish, consider automatically func-
tioning machines, possessing sensory apparatus and coupled to recording
devices capable of registering past sensory data and machine configurations.
We can further suppose that the machine is so constructed that its present
actions shall be determined not only by its present sensory data, but by
the contents of its memory as well. Such a machine will then be capable
of performing a sequence of observations (measurements)"

What types of measurements could an observer make? The same ones we make. We can measure mass, distance, duration, temperature.

If the observer makes clock readings, then that's a measurement of time.

Here's what Newton says:

"I do not define time, space, place, and motion, as being well known to all. Only I must observe, that the common people conceive those quantities under no other notions but from the relation they bear to sensible objects.
...
relative, apparent, and common time, is some sensible and external (whether accurate or unequable) measure of duration by the means of motion
...
Relative space is some movable dimension or measure of the absolute spaces; which our senses determine by its position to bodies"

So if an Everett observer used its senses to determine some distance, or some time, the measurement records fit Newton's definition of relative space and relative time.

 

[Cheetah]

So nothing to do with time then.

 

[Mike Helland]

So nothing to do with time then.

Everything to do with measurement.

Space and time being two very well known measurements.

If the observer never looks at a clock, then nothing to do with time.

If the observer looks at a clock, then the model predicts relative time.

 

[Ziggurat]

My position is that Everett's relative state formulation will probably be written with code in the near future.

No, it won't.

A modern GPU is basically a supercomputer to anyone writing code in the 90's.

I don't think you have any idea about scaling in computing quantum systems, and how difficult it is.

 

[Ziggurat]

If the observer never looks at a clock, then nothing to do with time.

Now that's just stupid. To the extent that time is defined by clocks, then anything and everything that changes with time is a clock of sorts. So an observer cannot help but look at a clock unless everything they look at (including themselves) is static. Which is not only unphysical, but also pointless.

 

[Mike Helland]

Now that's just stupid. To the extent that time is defined by clocks, then anything and everything that changes with time is a clock of sorts. So an observer cannot help but look at a clock unless everything they look at (including themselves) is static. Which is not only unphysical, but also pointless.

Exactly.

 

[Mike Helland]

anything and everything that changes with time is a clock of sorts.

For what it's worth, the "with time" is superfluous.

"Anything that changes is a clock of sorts."

That's the whole idea.

“It is utterly beyond our power to measure the changes of things by time. Quite the contrary, time is an abstraction at which we arrive through the changes of things.”
- Mach