Wednesday, November 18, 2015

An obsessive-compulsive's view on the universe, people and the origin of life

joão pestana

I must admit straightforwardly that I am, to a certain extent, an obsessive-compulsive. Though it's far from a serious case where I cannot leave the house without turning the knob precisely 13 times, it does causes me an itch or two from time to time. For instance, if I'm allowed to pick a number from a set of integers, I'll always choose multiples of 5 first, followed by prime numbers, odd numbers and only if no other choice remains, even numbers. This I do when I select the volume for the radio or the television and many other things. At first, it might seem that I like to go against the universe.

According to the second law of thermodynamics, the entropy of the universe as a whole must always increase. Entropy is the number of different ways you can arrange all the parts of a different system. Imagine that you own 2 pieces of LEGO, one red and one blue. Their entropy value is 1, because there is only one way you can arrange them. You can order the red one first or the blue one first, but that's the same order — just mirrored or rotated. Imagine that you break each LEGO in 2. You now own 4 pieces, two red and two blue and there are `C(4,2)=6` different ways you can arrange them. Split those again and you get `C(8,2)=28`. Notice how large the entropy of the system has increased by just splitting the original parts of the system in two two times! Another common definition of entropy is the measure of the disorder of a system and it must always increase.

I like to keep things in their place — properly organised — but the universe doesn't seem to like that. Am I trying to beat the universe at its own game? No, not at all or I'm failing miserably. The truth is that to create order, something else must become at least as disordered as the order I created. Imagine that you are trying to sort a 52 deck of playing cards in some order that you like. To do that, you are increasing the entropy of the universe by much, much more.

How? Every time you move, you waste energy which you have previously stored from food. That food — either animal or vegetarian — originated fundamentally from the Sun. Not all energy from the sun is converted into sugar by plants through photosynthesis, because some actually just warms up the plant. Your movements also push the air particles and increase their energy. Due to this, they collide even more with each other and break up and form new pairs. Remember how splitting 2 elements in two greatly increased the entropy of a system? Imagine how all the uncountable particles of air that split up increase the entropy of the universe!

We could say that everything in the universe acts as an entropy maximiser either willingly or unwillingly, like me. Take matter, for example, that wants to reach the lowest energy state it can. In order to do so, it must release all of its energy to elsewhere. If you drop a ball from yours hands while on the surface of the Earth, it will have its potential energy converted into kinetic energy during its travel towards the ground. While doing so, the ball loses some kinetic energy to the surrounding air and the remaining is lost on impact. Because the ball stood some height above the ground, it had a higher energy stored in itself — potential energy. At ground level, the potential energy of the ball is lower and is more stable — the ball will remain there. During its fall, the entropy of the universe increased.

Economists usually apply the same principle to people. They say that consumers are utility maximisers. There is some unknown function `u(x)` which is unique to every person and, given some information, it outputs the level of utility that person assigns to the information provided. We can say that if I prefer pears to apples, than my utility function given pears will have a higher value than if given apples.

`u( p e a r s ) > u( a p p l e s )`

Most of the time, we aren't aware of our own preferences. It's not hard to convince you that economists and economic models are at odds with the consumers' utility function. I believe we do maximise something whenever we perform a choice — even if it's not the best outcome possible. Given our knowledge at the moment and our expectations, we make an effort to select, from the set of all possible outcomes, the one that grants us our best chances possible. Imagine you can choose between two lottery tickets. The first grants you a prize of 100€ with 50% chance and the second the same prize, but with a 60% chance. Which one would you choose?

`u( l o t t e r y_2 ) > u( l o t t e r y_1 )`

If you're like me, you'll give a higher utility to the second lottery over the first one. Unfortunately, most of our decisions in life don't come out as easy as these two lottery tickets and so we are forced to extrapolate future results from current and past information. If we touched a poison ivy in the past, we're going to do avoid in the future. This happens, because we make use of information that it caused us harm in the past and we assume it will have the same result if we touch it again.

The whole point of this article is this argument. If the universe and all its contents are entropy maximisers, so are we — as part of the universe. The utility function is different and incoherent between people, but not the entropy maximisation principle. Willingly or unwillingly, we do increase the entropy of the universe more while being alive that if the whole set of particles that constitute us would on their own.

Although I would really like to call these ideas original, they are not. A final note on entropy and then I'll finish with some scientific literature for you to investigate on your own. It's possible that if you drop an entire bag of M&Ms to the floor, they will perfectly align in a circle. That is one possible final configuration of the act. The more likely scenario is one in which the M&Ms are all scramble in a seemingly random order.

Because the number of seemingly random configurations is much, much higher than the circle one, it is the one that is observed — because, you know, probabilities. The same principle applies to the energy configuration of the universe. It all scrambles because there are many more ways to randomly distribute it than to have it all organized somewhere as I would really like to.

Jeremy L. England published an article in The Journal of Chemical Physics, 139 entitled Statistical physics of self-replication in 2013. His idea is that life is a byproduct of maximizing the entropy or dissipation of energy. To the laws of physics, there is no difference between an inanimate object and a living organism — they're simply clumps of matter. The later one is much efficient at retrieving energy from its environment and dissipate it as heat. You should read this article and in England's own words:
You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant, (...)
It's both a beautiful and frightful thought to realize that perhaps when the universe finally reaches its end, that final state of maximum entropy, it may well be the state of ultimate order and everything is so well organized that it is indistinguishable from total caos.