Is Time the 4th Dimension in Physics?

[russ_watters]

Originally posted by jcsd
Yes indeed; I was going to post, pretty much the same thing: the existence of time is just as axiomatic as the existence of the x, y and z directions.

Ditto.

 

[jcsd]

Originally posted by Anton A. Ermolenko
Not exactly that way. The system of axioms (of a specific physical theory) may content time as axiom, and may not... time can be only a theorem (e.g. there are axioms of three-dimensional linear space and four-dimensional invariant, such as four-dimensional interval in the Minkowski space-time).

If we agree with time definition within the framework of quantum field theory, then time is exactly discrete.


Not exactly that way. Even if A₁-state differs from A₂-state by generalized coordinates and linear component of four-momentum is not equal to zero (of course it isn't) you can't observe motion, because you can't observe trajectory. You can localize it with a relative exactitude, nothing else.

Most physical theories DO have the existence of time as an axiom, infact I'm struggling to think of theory in which time is an emergant property (though I'm not saying there isn't one, I remeber years ago reading a book by Paul Davies in which he suggests time may of been an emergant property from the properties of the initla conditons in the universe).

Also, I will not claim to be an expert on QFT but I've yet to hear of a widely accepted physical theory which quantizes time.

 

[maumer]

Russ
No, we use the motion of something to MEASURE time.

Antiproton
First, time is not measured relative to motion... motion is measured relative to time. v=dx/dt.

Decide what you are doing!

 

[maumer]

Originally posted by Anton A. Ermolenko


Not exactly that way. Even if A₁-state differs from A₂-state by generalized coordinates and linear component of four-momentum is not equal to zero (of course it isn't) you can't observe motion, because you can't observe trajectory. You can localize it with a relative exactitude, nothing else.

Hello Ermolenko,
are you talking about the evanescent behaviour of particles? If yes, i agree with you that we can't see motion. But you see time in the transaction betweem two states. The transaction, at the end, is a result of a sort of a motion. Something has moved and you define time with a transaction; a sort of motion.
I can conlude that fluffy bunny is in right when he says that time is axiomatic. But an axiom is what you keep true although it could not be. What i was trying to explain is that time is an artificial creation to link some movement, that we use to set regular intervals like cesius atom vibration, to an other motion. I'm trying to say that you call time a motion. But time really doesn't exist. We can count how many vibrations cesius does and say: "three vibrations ago i was...". O.K.! I can accept it. But we are referring our lives to a motion of an atom. Not to time. You are calling time the atom vibration.
O.K. fluffy bunny, you're in right.

 

[Anton A. Ermolenko]

Originally posted by jcsd
Most physical theories DO have the existence of time as an axiom, infact I'm struggling to think of theory in which time is an emergant property (though I'm not saying there isn't one, I remeber years ago reading a book by Paul Davies in which he suggests time may of been an emergant property from the properties of the initla conditons in the universe).

Also, I will not claim to be an expert on QFT but I've yet to hear of a widely accepted physical theory which quantizes time.

Actually you take one quantization of continuous time for descrete nature of time. Within the framework of QFT the time is discrete. The secondary quantization concept allow to sustitude the time with indexes, because the main difference A₁-state from A₂-state is the index. We need the time only for synchronization of different physical systems. But it really is discrete.

Originally posted by maumer
Hello Ermolenko,
are you talking about the evanescent behaviour of particles? If yes, i agree with you that we can't see motion. But you see time in the transaction betweem two states. The transaction, at the end, is a result of a sort of a motion. Something has moved and you define time with a transaction; a sort of motion.

Of course not. Transaction from A₁-state to A₂-state not always implies a modification of localization in three-dimensional space, e.g. A₁-state may differs from A₂-state by number of virtual photons. And where is motion?

 

[russ_watters]

Originally posted by maumer
Decide what you are doing!

You took my quote out of context. You can do both depending on the type of events/motion being observed.

 

[maumer]

Originally posted by Anton A. Ermolenko
We need the time only for synchronization of different physical systems.

So time is the difference between two states?

 

[Anton A. Ermolenko]

Originally posted by maumer
So time is the difference between two states?

Bingo! If we agree with the concept of secondary quantization within the framework of QFT, then of course yes - the (local) time is only difference between two nearest states of the same physical system.

 

[maumer]

Originally posted by Anton A. Ermolenko
Bingo! If we agree with the concept of secondary quantization within the framework of QFT, then of course yes - the (local) time is only difference between two nearest states of the same physical system.

Mr. Bingo, could you assert time is axiomatic, too? A human mean?