Part 2, The Language of Physics, Chapter 6: The Entropic Principle
By Andy Walsh
We are blogging through the book, “Faith Across the Multiverse, Parables from Modern Science” by Andy Walsh. Today is Chapter 6: The Entropic Principle. The Entropic Principle refers to Second Law of Thermodynamics. From LiveScience: The laws of thermodynamics describe the relationships between thermal energy, or heat, and other forms of energy, and how energy affects matter. The First Law of Thermodynamics states that energy cannot be created or destroyed; the total quantity of energy in the universe stays the same. The Second Law of Thermodynamics is about the quality of energy. It states that as energy is transferred or transformed, more and more of it is wasted. The Second Law also states that there is a natural tendency of any isolated system to degenerate into a more disordered state. The Second Law indicates that thermodynamic processes, i.e., processes that involve the transfer or conversion of heat energy, are irreversible because they all result in an increase in entropy.
Walsh thinks that it is helpful to think about entropy and order in terms of symmetry and asymmetry, because those words carry less colloquial baggage that can give us the wrong intuition. Symmetry refers to the ability to swap things around and get something equivalent to what you started with. A box of air is symmetrical because you can swap around the molecules into all kinds of different arrangements and the result would be indistinguishable in terms of what we can measure like temperature. An asymmetrical box could have all the molecules squeezed to one side and the rest just empty space. Now there are far fewer equivalent arrangements because we’ve ruled out all the options where some molecules are in the now-empty side.
Asymmetrical arrangements are useful precisely because changes matter. When an asymmetrical system changes to a qualitatively different arrangement, there is an opportunity to do something useful. For example, imagine our box changing from the squished-to-one-side state to the all-spread-out-state. This transition will generate a net movement from one side of the box to the other, akin to a gust of wind. We could harness that wind with a turbine and generate electricity until the box reaches the all-spread-out-state, at which point the turbine will stop spinning. Walsh says:
Asymmetry is thus a structured or organized arrangement that can be qualitatively distinguished from other arrangements. These distinctions between arrangements imply that changes are meaningful and potentially useful. Symmetry by contrast is a state with a number of indistinguishable arrangements, rendering changes meaningless.
Walsh cautions that we need to be careful of two things in thinking about entropy or order and disorder or symmetry and asymmetry. One is that thermodynamic entropy deals specifically with the order or symmetry of molecules. An unsorted DVD collection may be more disordered than an alphabetized one, but the differences between the two are at the macroscopic level. At the molecular, there is likely no difference and so the thermodynamic entropy will be the same. We can apply our definition of symmetry to various levels, making it useful metaphorically, but we can’t work backward from it to thermodynamic entropy. We also need to be careful because our intuition of what makes something ordered or symmetrical may not always be accurate.
Walsh then points out that even though an isolated system increases in entropy, the Earth doesn’t qualify as an isolated system because it receives an input of energy from the sun. That is why life is possible on Earth. Plants are able to overcome the tendency to disorder by applying the sun’s photon through photosynthesis to convert high entropy substances from their environment, like carbon dioxide and water, into more structured, low entropy compounds. By this process, plants are able to use the order from the sun to build and maintain their own highly organized, asymmetrical structures.
The asymmetry of that organized state of the plant can then be transmitted up the food chain. Animals and people eat those plants, taking in organized molecules and using them to maintain their own ordered states. From this picture, we get a useful definition of life and death. Defining life, however, can be somewhat tricky; try coming up with a definition that includes bacteria but excludes viruses, ideas, and fire. The physicist, Edwin Schrödinger popularized an entropy-based definition; life is the process of keeping yourself ordered by making use of the asymmetry in your environment; conversely, death is the process of giving your internal asymmetry back into the environment.
The metaphor that Walsh reaches for is that Jesus as the “Word” and the “light of the world” (John 1:2-4) is the ultimate organizing principle in the universe and the ultimate bringer of life. In Him, we move from a disordered state to an ordered one, from higher entropy to lower entropy, from death to life. Apart from Him, entropy ultimately triumphs, and we move to the most disordered state: death.
John 11:25 Jesus said unto her, I am the resurrection, and the life: he that believeth in me, though he were dead, yet shall he live: 26 And whosoever liveth and believeth in me shall never die.
Another interesting analogy Walsh brings out is that by consuming plants and animals we maintain our ordered state. Likewise, by participating in the Eucharist, by consuming the body and blood of Christ, we maintain that life in Christ.
John 6:48 I am the bread of life. 49 Your ancestors ate the manna in the wilderness, yet they died. 50 But here is the bread that comes down from heaven, which anyone may eat and not die. 51 I am the living bread that came down from heaven. Whoever eats this bread will live forever. This bread is my flesh, which I will give for the life of the world.” 52 Then the Jews began to argue sharply among themselves, “How can this man give us his flesh to eat?”
53 Jesus said to them, “Very truly I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. 54 Whoever eats my flesh and drinks my blood has eternal life, and I will raise them up at the last day.
Then we get to the death of Jesus. Put simply, Jesus died so that we might live, just as the sun is exhausting itself it sustain us. In addition, we describe death as a process of disseminating stored information. Likewise the death of Jesus was a key reason why the gospel message spread as widely as it did. Walsh thinks that this entropic perspective helps us get our heads around one of the more challenging ideas of the gospel—that we are called to die just as Jesus did. Matthew 16:24 Then Jesus said to his disciples, “Whoever wants to be my disciple must deny themselves and take up their cross and follow me. By dying to ourselves we are putting more order into the world around us, even at the expense of introducing more disorder into our own lives; being a living sacrifice as Paul says in Romans 12:1. At the opposite end, when we enrich our own situation at the expense of others, there is an entropic sense in which we are eating or devouring their lives. Perhaps that’s why the imagery for Jezebel, who was guilty of “devouring lives” is prophesied and eventually comes to having her corpse devoured by dogs (1 Kings 21 and 2 Kings 9). The circumstances of her death should strike us as a potent reminder that, on way or the other, we will all wind up giving of ourselves so that someone else’s life can be more ordered. Walsh says:
Earlier we said that, in his death, Jesus called us all to die to ourselves. Doesn’t his resurrection undermine this, by doing the opposite? My take is that it doesn’t, because we defined dying to ourselves in terms of serving others. Jesus did not reverse his death at the expense of anyone else. Instead, he did it to initiate a reversal of the dying process that began when we cut ourselves off from God. He also did it to demonstrate that God alone can serve as the inexhaustible source of life-giving, entropy-lowering asymmetry, displaying another facet of his status as the ultimate axiom…
So we can die to ourselves by allowing some symmetry into our own lives to bring asymmetry to the lives of others. We follow God’s example as the vine and “carry one another’s burdens” (Galatians 6:2), bearing away what prevents others from flourishing, and “comfort those experiencing any trouble with the comfort with which we ourselves are comforted by God” (2 Corinthians 1:4).