Thursday, December 17, 2009

Entropy and making my bed.

I am not a neat freak.
I am not dirty per-se, I do not wallow in filth, but I am very disorganized and like to leave clutter around for my wife to trip over.

I also hate making my bed.




No, this is not my bed, nor are these my cats. (I do like cat's tho...)


I have always hated making my bed. Something about spending a few min in the morning flipping, folding and tucking just seemed wrong somehow. I mean, all that will happen later in the evening is I will mess it up again.
Of course, I cannot stand sleeping under a totally ruined set of blankets, but it takes far less effort and time to straighten those out after a few days of use. 
When my mother would tell me to make the bed however, telling her no because it will just get messed up never worked.


Then I encountered physics!

I learned about the second law of thermodynamics, or the universal law of entropy, and thought I had a well justified excuse for never making my bed. I was saving the universe!

A property of entropy is that in a system, a process that occurs will increase the entropy of the universe.


What is entropy? Well, simply put it can be thought of as a measure of disorder of a system.
Some of the properties of entropy are:
The entropy of the universe will always increase (or stay the same at best) even if in a local system the entropy can decrease.
Heat is considered to be directly related to entropy, as a value of its entropy.
Entropy is thought to set the direction of times arrow.



For instance, consider a child who has very carefully set up a toy solder army in a very specific and organized manner, with neat little rows of solders according to color, height, rank etc.



 In doing so, the child has decrease the "disorder", or entropy of the system of toy soldiers, but has also expended energy in making the arrangement. This expended energy is not 100 percent efficient at reducing the entropy of the system of toy soldiers, and some was wasted as heat. This heat increases the entropy of the child's surroundings, and consequently increases the entropy of the entire universe.

It even gets worse. Over a period of time, even if the child were to leave the soldiers alone, the state of disorder of the toy soldiers would naturally increase by itself. Dust, microbes, changes in temperature, quantum effects of decay, statistical impingement by cosmic rays would all serve to erode the plastic and over time the system becomes more disordered.





All these processes contribute to the increase in entropy of the universe!

Say a cat (I do like cats tho..) walks  by and dashes the toy soldiers into a wrecked battlefield of scattered plastic. Not only did the cat directly increase the disorder (entropy) of the system, but in doing so wasted some of its energy as heat, which increases the universes entropy. 




You can't win... or more precisely, the universe cannot win. 

Why is increasing the entropy of the universe a bad thing? 

As the entropy of a system increases, the ability to draw energy from it to do work decreases. The thermodynamic free energy decreases.

The ability of a process to draw energy from somewhere, or to use thermodynamic free energy allows for the process to decrease entropy locally (at the expense of the universe). This work can be used to create stars, planets, babies, snow flakes, and all the wonders of the universe.
However, if the entropy of the universe reaches a maximum, it will evolve toward a state known as the Heat Death

This means there is no thermodynamic free energy, and therefore no way to continue creating new stars, new life or new snowflakes. And this is a major bummer.


Every act you do sends the universe closer to heat death. Every act of creating and kindness, of hatred and havoc increases the disorder of the universe. Nothing can be done to stop this, but why not spend that energy, and waste some heat doing good? Create, be kind!

So, to extend the time till the heat death of the universe by just a little bit, I claim that I should put the energy of making my bed to better use!
I am saving the universe! (Take that you environmentalists you!)


My wife is not buying this...

1 comment:

  1. Of course, this is a macro-scale reason being applied to a local scale. And I thought you were an environmentalist? Unless the prius is just for saving gas money...

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