[Greg Boyles]

Entropy = chaos.

Chaos theory dictates that it can generate order, e.g. forget the name but those solutions that oscillate between two equilibrium states in rythmical manor.

So if chaos can generate or foster order then how is that entropy only ever increase in theory?

[swansont]

Greg Boyles, on 6 December 2011 - 06:27 AM, said:

Entropy = chaos.

No.

[Greg Boyles]

swansont, on 6 December 2011 - 11:18 AM, said:

No.

Quote

Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process

Quote

Chaos theory studies the behavior of dynamical systems that are highly sensitive to initial conditions, an effect which is popularly referred to as the butterfly effect.

OK so they are not the same thing.

It requires energy to reverse entropy, e.g. biogenisis, planet and star formation due to gravity. And as long as there is life in particular there is a contiual cycling between increasing and decreasing entropy. Is this correct?

Or is, for example, biogenisis some how still consistent with the universal rule of increasing entropy?

If so then how because it is one thing that I have never understood about entropy.

[swansont]

Greg Boyles, on 6 December 2011 - 12:15 PM, said:

OK so they are not the same thing.

It requires energy to reverse entropy, e.g. biogenisis, planet and star formation due to gravity. And as long as there is life in particular there is a contiual cycling between increasing and decreasing entropy. Is this correct?

Or is, for example, biogenisis some how still consistent with the universal rule of increasing entropy?

If so then how because it is one thing that I have never understood about entropy.

It depends on how you define your system. Even within a system the entropy can be lowered in one part with no importation of energy, as long as it rises elsewhere. For biological process you have the sun as an external source of energy and the output of the organism in question is going to have entropy. In star or planet formation, you give off energy in order to form a bound system.

[Greg Boyles]

swansont, on 6 December 2011 - 12:52 PM, said:

It depends on how you define your system. Even within a system the entropy can be lowered in one part with no importation of energy, as long as it rises elsewhere. For biological process you have the sun as an external source of energy and the output of the organism in question is going to have entropy. In star or planet formation, you give off energy in order to form a bound system.

The Earth is a closed system. Regardless of all that goes on on planet earth, there is no increase in O, C and N etc. These are merely cycled through organisms and geological structures etc.

Energy is neither destroyed nor created, merely cycled through various processes.

Entropy is the available energy in a system to do work.

Does that then mean that the universe is a closed system where entropy neither increases or decreases but merely cycles (in the opposite direction of the flow of energy) between various processes?

Maximum entropy would mean no available energy to do any work? E.G. If all the matter in the universe was in the form of neutron stars, white dwarfs and black holes etc.

White dwarfs eventually become cold and give off no energy or matter. But can this happen to neutron stars? Even black holes are supposed to entually 'evapourate' by giving off energy from what I have read of Steven Hawkings' theories. So does that mean that their mass and energy is eventually returned to the cosmos to do some form of work? I.E. Available energy increased / entropy decreased?

This post has been edited by Greg Boyles: 6 December 2011 - 01:13 PM

[CaptainPanic]

Greg Boyles, on 6 December 2011 - 01:01 PM, said:

The Earth is a closed system.

Only regarding matter (and even then we're not 100% closed - think of asteroids, or space dust entering the atmosphere), but as far as the energy balance, we certainly are not a closed system (most of the energy comes from the sun, and we also radiate heat back into space).

[Greg Boyles]

CaptainPanic, on 6 December 2011 - 01:09 PM, said:

Only regarding matter (and even then we're not 100% closed - think of asteroids, or space dust entering the atmosphere), but as far as the energy balance, we certainly are not a closed system (most of the energy comes from the sun, and we also radiate heat back into space).

OK, almost closed then.

Matter might be added through asteroids and space dust but, short of a catastrophic meteor hit and apart from our space probes and satellites, no matter leaves earth for all intents and purposes.

[CaptainPanic]

Greg Boyles, on 6 December 2011 - 01:17 PM, said:

OK, almost closed then.

Matter might be added through asteroids and space dust but, short of a catastrophic meteor hit and apart from our space probes and satellites, no matter leaves earth for all intents and purposes.

Almost closed regarding matter... but you discuss entropy, and that is part of the energy balance...

In other words: the sun plays a huge role on earth, and influences the entropy on earth. The sun can turn chaotic systems to ordered systems (think of desalination of sea water, making pure water from salt water with solar power).

[csmyth3025]

Greg Boyles, on 6 December 2011 - 01:17 PM, said:

OK, almost closed then.

Matter might be added through asteroids and space dust but, short of a catastrophic meteor hit and apart from our space probes and satellites, no matter leaves earth for all intents and purposes.

You might say that the Earth's atmosphere is "almost closed" at the present time - but this has not always been the case and will not always be the case in the future. You might want to read the rather lengthy article that covers this subject here:
http://www.scientifi...eir-atmospheres

Also, you may want to keep in mind that entropy is a measure of the energy available to do work. Whether the Earth is gaining or losing mass at present has very little to do with the amount of energy available on the surface of the Earth to do work. This energy is largely supplied either directly or indirectly by the radiation we receive constantly (and in copious quantity) from the sun.

Chris