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Physics, Astronomy & Cosmology / Re: Can we lay nothing to rest?
« on: 21/11/2014 19:06:55 »
Regarding time and change:
We can think of a more generalized change as the partial derivative of some characteristic of the universe (or any system) with respect to some parameter. ∂something/∂time is one of the most common meaning of change, but we could chose many other parameters, such as position, temperature, pressure, composition etc. We could discuss the fundamentality of these parameters, but then again, how fundamental is time?
Can there be time without change? Sure, even if ∂something/∂time = 0, that doesn't mean that there is no time, it's just not relevant to that "something". For instance, think of all the parameters that are conserved in Newtonian physics and thermodynamics--as far as the total momentum of the universe is concerned, time is meaningless.
Causality gives time its directionality, and entropy is the proof.
We can think of a more generalized change as the partial derivative of some characteristic of the universe (or any system) with respect to some parameter. ∂something/∂time is one of the most common meaning of change, but we could chose many other parameters, such as position, temperature, pressure, composition etc. We could discuss the fundamentality of these parameters, but then again, how fundamental is time?
Can there be time without change? Sure, even if ∂something/∂time = 0, that doesn't mean that there is no time, it's just not relevant to that "something". For instance, think of all the parameters that are conserved in Newtonian physics and thermodynamics--as far as the total momentum of the universe is concerned, time is meaningless.
Causality gives time its directionality, and entropy is the proof.