Can entropy be zero

Answer 1

I am not sure whether you refer to delta S (change in entropy) or entropy itself. So I'll answer for both.

For S (entropy), which is defined by the function S=kln(omega), where k is Boltzmann's constant and omega is the number of microstates corresponding to a given state, the answer is no. Why? Omega (the number of microstates possible for a certain state) can never be smaller than one. Since Boltzmann's constant is a positive number and ln(omega) will always be greater or equal to zero, entropy will never be negative.

However, when calculating delta S (change in entropy in a thermodynamic process), yes entropy can be negative. Remember entropy is essentially the state of disorder of a system since (on a macroscopic level) the natural progression of the world is from order to disorder. (For example, there are more ways to have a messy room than to have an impeccable, neat room). For the change in entropy to be negative just think of it in terms of the room analogy: initially, it was messy, but then it got neater. The state of disorder of things was lessened. Applying this to a chemistry example:

CO 2 (g)--> CO 2 (s)

An element/compound in a gaseous state always has a greater state of entropy (gaseous molecules are more free to move). However, an element/compound in a solid state has a smaller state of entropy because molecules in a solid are less free to move. Smaller state of entropy - greater state of entropy=negative entropy

Answer 2

Entropy can theoretically approach zero, but it cannot actually reach zero. This is because entropy is a measure of the number of possible ways a system can be arranged, and achieving perfect order or organization (zero entropy) would require every particle to be in a precise, specific arrangement, which is not possible due to the inherent randomness of particles.

Answer 3

You've likely seen this, but:

THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.

We simply don't know enough about the source of energy to know. Were an absolute insulator (a material that lets absolutely no energy through), and shaped into a ball, then entropy could hypothetically be resisted. However, this would not REVERSE entropy, as no new energy could be brought in without opening the sphere and letting the contents escape.

What many people don't understand is that there is no actual true entropy. When energy leaves something, it doesn't cease to exist, but simply goes to a spot that we can't use it. The disorganization of all energy, the placing of each particle apart and out-of-reach, is what commonly thought of entropy actually is.

With the theory that the (our) universe is closed, and nothing escapes, the scattered energy could be floating around, occasionally meeting, and possibly bouncing off the borders of the universe. EVENTUALLY, which could be in an unimaginable amount of time (Literally unimaginable. You can conceive of the inconceivability, but not the actual number.), the particles of energy and whatnot could eventually meet again in sufficient numbers to be worth something, hopefully another Big Bang.

With the theory of an open universe, there are two different (relevant) possibilities. The first is that there are infinitely more BB's (Big Bangs) all over our plane of existence, that our BB was not the only one, and that the expanding matter of each can pass that of other BB's. Should this be the case, there is an infinite amount of energy in existence, and more of anything can EVENTUALLY be encountered again.

If, however, we are the only Big Bang, and there is no other source of anything, we're theoretically screwed. (Not to worry, though: It's actually more likely that there are more Big Bangs than that we're all alone.)

Of course, in any of these, there is the possibility that our Universe's (from our Big Bang) gravity will be enough to catch the far-flung galaxies and draw them back in for "The Big Crunch", when everything gets squished into one point again, and hopefully Banged again.

I believe that the last person to answer this question probably had some understanding of different universe theories, but didn't quite get what entropy was.

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In general entropy is the decay of a system from order to chaos. It can be reversed, locally. However to do so requires work, and energy, which is obtained by taking a different ordered system and reducing it further towards chaos. So while I may reverse entropy in my room (it is cleaner) I've increased the entropy in my body, in excess of what I've cleaned up.

Answer 4

Sadly, In fact, it is impossible to reduce entropy. One derivative of the the second law of Thermodynamics clearly states that "In a system, a process that occurs will tend to increase the total entropy of the universe." (http://en.wikipedia.org/wiki/Second_law_of_thermodynamics).

However, this is derived from Thermodynamics and therefore, does not consider the factor of time over the reaction or work being considered. Accordingly, it is possible that sustainable design and the use of products that may serve repeatedly (such as a glass cup, f.e) may inflict a lesser addition of entropy to the universe than would the repetitive use of few others that required less energy to produce, but are very often replaced (such as a plastic disposable cup).

In other words, if you drink form a glass cup may times, it is possible that the addition of entropy to the universe is less than what it would have been if you had drunk from a different plastic disposable cup each time. This is despite the fact that the initial entropy added to the world by the production of the glass cup is tens of folds more than that of producing a paper cup.

Written by Micha Kemelman

Answer 5

First, entropy is not energy. Entropy has the units of energy/temperature.

Energy can always be converted into less usable forms, so I guess the answer to your question is "yes". However, this is irreversible; less usable forms can not be converted into more usable forms. This is expressed by the concept that entropy can only increase, not decrease. Entropy is a measure of irreversibility.

Answer 6

There is as yet insufficient data for a meaningful answer

Answer 7

no