Hello fellow bags of water. My name is Roger Jones and I am coming to you from steamy downtown Pensacola. I have something very special to talk about, today. This may be the most important scientific post I do in a while. I want to talk about the Second Law of Thermodynamics and what the law has to do with the creation of life.
Water is important for life
As we have pointed out in previous posts, water is important for describing life as we know it on Earth. Space scientists who are looking for life as we know it are searching the cosmos for water. But in this post, I would to discuss the possibility of life in all its generality. I want to talk about life that may not be based on chemistry at all.
The Second Law is more important
The Second Law is even more important than water for the creation of life. The Second Law, in its simplest form, can be stated, “Matter and energy tend to spread.” What is so meaningful about that simple sentence. After all, it is not surprising that cream spreads into coffee when stirred. We think of disorder as matter and energy that are well spread. We give this disorder the name “entropy.” The Second Law states that the entropy of matter and energy increases or, at minimum, does not decrease. An implication of this law is that all the matter and energy in the universe will eventually become a uniform heated soup. There will be no structure to the universe. Physicists usually say, The Universe will die in a random heat bath.”
Let’s look at a simple simulation of what we are talking about. Here you see a box with some molecules in it. The box I divided into an upper chamber and a lower chamber by membrane. The membrane is perforated so that molecules can pass through a hole from one chamber to another.
Initially, all the molecules were in the upper chamber. But as time goes on, molecules occasionally find their way through the hole in the membrane and move into the lower chamber. Molecules in the lower chamber occasionally wander through the hole back into the upper chamber. At first almost all the molecules passing through the membrane travel from the upper to the lower chamber, but as the population of the lower chamber increases more and more molecules in the lower chamber move to the upper.
Eventually, the number of molecules in each equal size chamber is nearly the same, with as many molecules passing upwards as downwards. The molecules have spread as much as they can in this configuration. This is a state of maximum disorder—maximum entropy.
Not only did the molecules spread to both chambers, but so did their energies. Each molecule had an energy of motion. This energy of motion is now spread as the molecules are spread between the chambers.
The Second Law creates fictitious “forces”
If I did not tell you that the molecules are moving around randomly and there are no forces applied to the molecules other than when they run into each other or a wall, then you might say that there appears to a force that moves molecules from high-density regions to low-density regions. The Second Law creates fictitious forces that seemingly act on matter and energy like real forces.
Spontaneous organization is very unlikely
Our experience tells us that we would be very surprised to see all the molecules spontaneously move to one chamber or the other. This is yet another way of expressing the Second Law; “Spontaneous organization is very unlikely.” This observation has been used by some religions to justify the need for an external creator to create life. It turns out that even though the Second Law destroys order, the Second Law can also create order in local patches.
Wait. There are examples of matter and energy not spreading. Except for my midsection, I do not see my body spreading out all over the universe. My body is organized into organs and cells and other orderly collections of matter. Cities are collections of matter and energy that have congregated and are segregated into organized social organs. Computers are collections of matter and energy that have aggregated matter and energy into something useful. Hurricanes are concentrations of energy.
Now just how does the Second Law create local order?
Now just how does the Second Law create local order? These examples actually support the second law when examined in more detail. The Sun is a concentration of matter and energy. The matter and energy in the Sun are constantly being radiated away, the matter and energy is spreading. The Sun is becoming less organized as it spreads across the universe.
The Earth sits in this flow of matter and energy from the Sun. The Earth is bombarded by energy from the Sun. As the solar light hits the atmosphere thermal gradients are created.
For instance, if the sunlight makes it to the ground, the ground heats up and then the ground heats up the cooler air on top of it. This creates a temperature gradient. This temperature gradient is a little bit of order where matter and energy are not yet thoroughly spread. This little piece of order can generate a hurricane if conditions are right. The hurricane can transfer heat very efficiently from the ground to the upper atmosphere and to the poles. Compared with the typical random motion of air molecules, hurricanes have very ordered and organized motion of matter. As hurricanes dissipate the matter and energy in the hurricane is spread to other regions of the atmosphere and the planet. There is ultimately a net spread of matter and energy, although locally in space and time little bits of order were created from the flow of entropy.
Eddies in the Stream
We can think of the spread of matter and energy as a flow of entropy like a river of water. Structures like hurricanes and living creatures are eddies in the stream of entropy. They are little backwaters in which the flow is back upstream for a short period before the flow is carried to the ocean if we are talking about water, or the great heat bath if we are talking about entropy.
We are not alone
Complexity in space and time can occur whenever matter and energy are spreading very fast; whenever the flow of entropy is great. This happens in many places in the universe, not just on our little planet, but in supernovas and black holes and a million other places. We should not expect these other eddies in entropy flow to look or act anything like terrestrial life, or even to be based in chemistry.
Read more in Confronting Complexity by Casti, Jones, and Pennock
Extreme social events (X-Events) can occur when a complexity mismatch occurs in a society and when the social mood is negative. To learn more about how complexity mismatch and inequality, due to abundance and uneven distribution of abundance, lead to drastic social restructuring, check out Confronting Complexity.
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