[survivorboi]

I read that the 2rd law of thermodynamics hates the wall, said by some poet. Why?? I don't get it... :p

[ebaines]

You may be referring to a poem by Robert Frost called "Mending Wall":

Something there is that does not love a wall,
That sends the frozen-ground swell under it,
And spills the upper boulders in the sun,
And makes gaps even two can pass abreast.

Complete text is here: Frost, Mending Wall

Frost is writing about how stone walls fall apart and require mending each spring, and how it is a time to meet your neighbor as you set the stones right again. The poem concludes with the famous "good fences make good neighbors" line.

Frost doesn't mention the 2nd law. But to an engineer the way that the wall's stones become scattered is an example of increasing entropy, as the orderliness of the stone wall devolves into the chaos of a pile of stones.

[survivorboi]

How how is the stone wall shattering make heat flow from heat to cold? That is needed for increase in entropy

[ebaines]

You are partially correct - heat flow is needed for classical thermodynamics. However, in statistical mechanics it is possible to calculate a system's entropy based on the state of each constituent particle. The formula is:



Where k is Boltmann's constant and N is the total number of microstates available to the system. In this way the entropy of a bunch of scattered stones is higher than the entropy of a perfectly ordered wall, because the number of possible states for the "scattered" condition is much higher than the number of possible states for the "ordered" condition.