[K2Cr2O7]

Hello all.

I understand what entropy is in terms of it being a measure of disorder, and how the entropy change of a reaction can be used to determine how likely it is that a reaction will take place.

But what I still fail to grasp is why entropy is so important - why does the universe strive for disorder? All of the texts that I have read have acknowledged the importance of entropy, but never do they explain it.

If anyone could explain this to me I would be much obliged.

[Mitch]

why does the universe strive for disorder?

That seems more of a philosophical question. But, if the disorder of the universe didn't increase for spontaneous reactions, one could start imagining heatless light sources and perpetual motion machines.

[Dude]

It's been a while since I've taken a chemistry course, but I never liked the concept of "disorder" or messy rooms to try to describe entropy.  I agree with the term "molecular friction" as a better way to describe entropy.  It is energy expended that does not go into accomplishing a task. 

[Dan]

I'm not a physical chemist, but I would say that if it didn't, we would not be here to observe the universe so....

[Yggdrasil]

The way I see it, it's all a matter of probability.  It is more likely for molecules of two separate populations to be mixed then separate.  Over time, the universe proceeds toward the most likely state, which is the most disordered state.

[zeifer_roth]

this is a little philosophical but here goess....yes it is the natural order of things to be disorder.... it is postulated from the second law of thermodynamics that for every process that happens ...
, entropy is genereated... as mankind progresses, it develop many processes and technolgies and for this to happen entropy is generated as a result the disorderliness is is increasing..
the world is getting more and more chaotic...
there is war, famine, disease,crime,  disaster and etc. let alone, nature will be more and more chaotic ..
but it is also postulated from the 2nd law that to shift the process from disorder to a more order situation. external energy must be applied and work is the external energy needed..it is both (scientific and literal work).. and to obtain reversibility maximum reversibility maximum work must be applied... man must work in order to attain peace, stability, healthy condition.. they must work and strive to find answer and reverse the process of disorderliness..  <",>

[Borek]

That's all more or less simple probability. For every system only some states can be considered ordered, there are much more states that look chaotic. Thus if you select system state at random (for example observing it at any given moment) you are more likely to see it unordered. In terms of probablity it means that unordered states are much more probable than ordered ones. That's why disorder is more natural than order.

Note that we don't define "ordered" here - but intuition should work well enough, like "all red marbles in the same box" as opposed to "every box filled mixed marbles of all colors".

How do the probablity convert to entropy? That's what statistical thermodynamics is all about

[K2Cr2O7]

My thanks to all who replied. I feel the universe makes an itsy bit more sense now.

[Donaldson Tan]

More entropy can translate to a greater diversity of things around us.