The Stack Overflow podcast is back! Listen to an interview with our new CEO.
2 added 595 characters in body
source | link

If time exists separate from the course of increasing entropy, as imagined by Boltzmann, how could we know? Our memory is an exothermic chemical reaction, completely dependent on increasing entropy to store information. And the rest of our sense of time is an extrapolation of our experience of accumulating memory.

So, I would contend that sheer thermodynamics need not prove the direction of time, our physiology ties us to a single arrow, instead. But that is the arrow of increasing entropy, which may not align perfectly with any specific dimension of spacetime.

From this point of view, we must inhabit a part of the history of the universe where entropy is relatively low, and entropy must decrease fairly continuously as you move away from points of low entropy and toward points of high entropy in all dimensions, including any 'time' dimensions. But heat does this in space, and we can assume it would have to do so in time.

Indeterminacy can be accounted for in this model by the fact that the progression of entropy iswould be erratic, so time is not strictly unidirectional, only macroscopically so. The very high level of order in our local space would mean that time never moves backward very fast or for very long, upstream through the sort of 'osmotic pressure' of entropy along the temporal direction. As the 'fluctuation theorem' proves, this pressure remains very, very high until entropy becomes nearly maximal.

The proposed gedankenexperiment would not make sense in this kind of world. An empty space is automatically both minimal and maximal in entropy, and there would be no reason for time to 'move' forward from there. Only in a universe with enough complexity for accumulating entropy to appear continuous could there be something like time as we know it. So space might not have been 'initially' empty, and attempts to project time too far backward may lack logical content. Whatever the underlying structure of time is, against which entropy moves, it could act quite differently in a much simpler place.

If time exists separate from the course of increasing entropy, as imagined by Boltzmann, how could we know? Our memory is an exothermic chemical reaction, completely dependent on increasing entropy to store information. And the rest of our sense of time is an extrapolation of our experience of accumulating memory.

So, I would contend that sheer thermodynamics need not prove the direction of time, our physiology ties us to a single arrow, instead. But that is the arrow of increasing entropy, which may not align perfectly with any specific dimension of spacetime.

From this point of view, we must inhabit a part of the history of the universe where entropy is relatively low, and entropy must decrease fairly continuously as you move away from points of low entropy and toward points of high entropy in all dimensions, including any 'time' dimensions. But heat does this in space, and we can assume it would have to do so in time.

Indeterminacy can be accounted for in this model by the fact that the progression of entropy is erratic, so time is not strictly unidirectional, only macroscopically so. The very high level of order in our local space would mean that time never moves backward very fast or for very long, upstream through the sort of 'osmotic pressure' of entropy along the temporal direction. As the 'fluctuation theorem' proves, this pressure remains very, very high until entropy becomes nearly maximal.

If time exists separate from the course of increasing entropy, as imagined by Boltzmann, how could we know? Our memory is an exothermic chemical reaction, completely dependent on increasing entropy to store information. And the rest of our sense of time is an extrapolation of our experience of accumulating memory.

So, I would contend that sheer thermodynamics need not prove the direction of time, our physiology ties us to a single arrow, instead. But that is the arrow of increasing entropy, which may not align perfectly with any specific dimension of spacetime.

From this point of view, we must inhabit a part of the history of the universe where entropy is relatively low, and entropy must decrease fairly continuously as you move away from points of low entropy and toward points of high entropy in all dimensions, including any 'time' dimensions. But heat does this in space, and we can assume it would have to do so in time.

Indeterminacy can be accounted for in this model by the fact that the progression of entropy would be erratic, so time is not strictly unidirectional, only macroscopically so. The very high level of order in our local space would mean that time never moves backward very fast or for very long, upstream through the sort of 'osmotic pressure' of entropy along the temporal direction. As the 'fluctuation theorem' proves, this pressure remains very, very high until entropy becomes nearly maximal.

The proposed gedankenexperiment would not make sense in this kind of world. An empty space is automatically both minimal and maximal in entropy, and there would be no reason for time to 'move' forward from there. Only in a universe with enough complexity for accumulating entropy to appear continuous could there be something like time as we know it. So space might not have been 'initially' empty, and attempts to project time too far backward may lack logical content. Whatever the underlying structure of time is, against which entropy moves, it could act quite differently in a much simpler place.

1
source | link

If time exists separate from the course of increasing entropy, as imagined by Boltzmann, how could we know? Our memory is an exothermic chemical reaction, completely dependent on increasing entropy to store information. And the rest of our sense of time is an extrapolation of our experience of accumulating memory.

So, I would contend that sheer thermodynamics need not prove the direction of time, our physiology ties us to a single arrow, instead. But that is the arrow of increasing entropy, which may not align perfectly with any specific dimension of spacetime.

From this point of view, we must inhabit a part of the history of the universe where entropy is relatively low, and entropy must decrease fairly continuously as you move away from points of low entropy and toward points of high entropy in all dimensions, including any 'time' dimensions. But heat does this in space, and we can assume it would have to do so in time.

Indeterminacy can be accounted for in this model by the fact that the progression of entropy is erratic, so time is not strictly unidirectional, only macroscopically so. The very high level of order in our local space would mean that time never moves backward very fast or for very long, upstream through the sort of 'osmotic pressure' of entropy along the temporal direction. As the 'fluctuation theorem' proves, this pressure remains very, very high until entropy becomes nearly maximal.