Tag Archives: Second Law of Thermodynamics

A Guide to Reality, Part 9

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Alex Rosenberg begins chapter 4 of The Atheist’s Guide to Reality by pointing out how wasteful biological processes are. For example, a frog or fish may lay thousands or even millions of eggs and only produce a few offspring. Many organisms go through an entire life cycle without having any offspring at all. In addition, 99% of the species that have ever existed are now extinct, partly as the result of various prehistoric cataclysms (like the asteroid that wiped out the dinosaurs).

Rosenberg says this is what we should expect from the Second Law of Thermodynamics: “a lot of order relentlessly turned into entropy” [75]: 

Can any process produce entropy as fast as natural selection?… Build a lot of complicated devices out of simpler things and then destroy all of them except the few you need to build more such devices… [Adaptations] persistently get more complicated and so use even more energy to build and maintain themselves…. Any process competing with natural selection as the source of adaptations has to produce adaptations from non-adaptations and every one of the adaptations it produces will have to be rare, expensive and wasteful [77].

However, Rosenberg’s main thesis in this chapter is that it’s logically impossible to reconcile God and Darwin (although many have tried). He begins with the traditional idea that God is omniscient and omnipotent (aside from being unable to perform impossible tasks like creating a rock so heavy He or She can’t lift it). Rosenberg also assumes for the sake of argument that God intended to create us or something like us “in His image”.

So, assuming that God knows everything, can do anything, and wanted us to exist, how can we harmonize God and evolution? The common approach is to suggest that God used evolution to make us, either by kicking off the process long ago, knowing it would eventually lead to us, or by manipulating evolution at key points, with the same result. In other words, evolution is part of God’s plan.

A problem with this idea, as Rosenberg explains, is that natural selection is a matter of probabilities. That’s what we should expect from the Second Law of Thermodynamics. Mutations just happen. Organisms that might do very well never get the chance because of some random event (like being eaten while still in the nest). There is no guarantee that particular species will evolve. That’s what science tells us.

If God cooked the evolutionary books, therefore, interfering with the randomness of evolution, Darwin got it wrong. We didn’t evolve in the way the theory predicts. On the other hand, if God let evolution take its random course, He or She didn’t know what the result would be. Our evolution wasn’t planned. Either evolution is a random, probabilistic process or it isn’t. You can’t have it both ways.

My guess is that a proponent of intelligent design or creationism would say “so much for evolution”. It doesn’t work exactly like the biologists say. So what? Or that God in His infinite wisdom can arrange things any way He wants. It’s all way beyond our understanding.

Personally, I don’t have any religious faith that needs to be reconciled with Darwinism. But what if you’re serious about reconciling your faith and your scientific views? Is there a good response to Rosenberg’s argument?

I think there is. My first reaction to Rosenberg’s argument in chapter 4 is that he seems to be ignoring something he discussed in chapter 2, namely, the “multiverse”. As Rosenberg pointed out, many theoretical physicists, perhaps most of them, think that our universe is just one among many, where “many” could be a truly vast number, even an infinite number. But if there really is a multiverse, it seems beyond question that people like us were certain to evolve in universes here or there, given enough time and randomness. God, being omniscient, could have initiated the multiverse knowing full well that people just like us would eventually exist in some of its parts. If anyone would, God would understand that if you roll the dice often enough, you’ll eventually get all the combinations.

Along with Rosenberg, we can accept the fact that evolution is a truly random process in our universe. It might even be a random process in every universe. But if there are enough universes around, pretty much everything will end up evolving somewhere or other many, many times. If that’s God’s plan, there is no conflict with the Second Law or the theory of evolution. God and Darwin can be reconciled.

My other reaction to Rosenberg’s argument is that he should take into account what physicists and many philosophers say about the nature of time. I have trouble with the idea, but the current scientific view of time is that all moments are equally real. Ours is a “block” universe in which there is no past, present or future; there is merely earlier and later. It isn’t clear to me at all how the universe can be probabilistic and physical events truly random if what’s going to happen is just as real as what did happen, but that’s what physicists believe. I guess it just means the past doesn’t fully determine the future at the quantum level, even though future events are just as real as past events. 

Anyway, if anyone can reconcile quantum indeterminacy and a block universe, it’s God. After all, according to the theologians, God is outside of time (whatever that means). God isn’t sitting around, waiting to see what happens. As Rosenberg says, God is “omnipresent”, which means there is nothing in space or time that is off-limits to God. Being omniscient as well, God knows the whole story. That should be especially easy for God if earlier and later events in the story are equally real.

For that reason, even if evolution is random and inherently unpredictable, God is fully informed. Every event, earlier or later, is right there in the history of the universe for God to know about. If what physics tells us is true, it’s a perfect setup for someone like God, being outside of time, to know how evolution eventually leads to people like us. Randomness prevails, Darwinism is correct and God knows the whole story anyway. If indeterminacy and the supposed nature of time are in harmony, so are physics, Darwin and God. 

Rosenberg ends chapter 4 with some remarks on purpose:

Scientism means that we have to be nihilists about the purpose of things in general, about the purpose of biological life in particular, and the purpose of human life as well….There isn’t any rhyme or reason to the universe. It’s just one damn thing after another. Real purpose has been ruled out by physics [92].

I don’t think he’s right about that, but to avoid repeating myself, we’re going to move on. In our next installment, we’ll consider chapter 5. It’s called “Morality: the Bad News” (the good news supposedly comes later).

A Guide to Reality, Part 8

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Chapter 3 of Alex Rosenberg’s The Atheist’s Guide to Reality is called “How Physics Fakes Design”, although Professor Rosenberg would be the first to object that physics isn’t the kind of thing that can fake anything. His point, of course, is that everything that looks like it’s been designed in the natural world (the human eye, for example) is merely the result of activity at the atomic and molecular level, which itself results from subatomic particles doing what they normally do.

In fact, Professor Rosenberg holds that things that really were designed (like your computer) are the result of the very same natural laws. Design, wherever it appears to occur, whether the result of evolution or conscious effort, is just another illusion. 

In this chapter, however, Rosenberg is focused on evolutionary adaptation:

If the physical facts fix all the facts, then the emergence and persistence of adaptations had better result from the laws of physics alone. In fact, they had better be the result of the operation of thermodynamics. Otherwise we will have to admit that there is more going on in the universe than physics tells us there is. Some physicists may be okay with this, but scientism has to reject it. We need to show that the process Darwin discovered starts with zero adaptations and builds them all as the result of the laws of physics alone. (51-52).

Rosenberg begins by offering a statement of the three essential features of the theory of natural selection, as stated by the biologist Richard Lewontin:

  1. There is always variation in the traits of organisms, genes, hives, groups or whatever it is that replicates or reproduces;
  2. The variant traits differ in fitness;
  3. The fitness differences among some of the traits are inherited.

As Rosenberg explains, the replication or reproduction that occurs in nature doesn’t always result in an exact copy being made (mutations occur, for example). He prefers calling this “blind variation” instead of “random variation” to emphasize the point that nature doesn’t cause these variations on purpose. Most such variations yield no benefit. Occasionally, one does. A “beneficial” variation is one that tends to be passed on to the next generation. Given enough time, such variations can result in complex structures like the eye. Evolution occurs.  

Getting back to physics, Rosenberg argues that the second law of thermodynamics (closed systems tend toward disorder) makes natural selection “inevitable” (although at the end of the chapter he says that the second law only makes it “possible”). He admits that the relationship between the second law and natural selection is puzzling, since natural selection seems to increase the amount of order or organization in the world. But he quickly disposes of this objection by pointing out that the second law only requires a “net increase” in disorder over time. Organization will occasionally increase, but almost always at the cost of more disorganization elsewhere (as when organisms grow by digesting food).

Next, in the space of 11 interesting pages, Rosenberg shows how molecular activity, all subject to the second law, results in what he calls “molecular evolution” (69). As he explains it, there is a lot of “thermodynamic noise” in the universe. Molecules are constantly copying themselves, sometimes imperfectly, and forming bonds with each other. These processes result in new molecular forms. Some molecules are more stable than others, meaning that they will tend to last longer in particular chemical environments. As environments change, however, certain molecules become less stable and break apart, while others come together, just as organisms adapt or fail to adapt to changes in their environments. These various processes satisfy the criteria for evolution described above:

Natural selection requires … reproduction, variation and inheritance. It doesn’t really care how any of these three things get done, just so long as each one goes on long enough to get some adaptations. Reproduction doesn’t have to be sexual or asexual or even easily recognized by us to be reproduction. Any kind of replication is enough (59).

The same goes for variation and inheritance. I would add that these processes must occur in an environment filled with enough matter and energy to keep things moving along. Then, through the course of countless such chemical interactions over immense periods of time, complex organic molecules can develop:

Thermodynamic noise constantly makes more and more different environments – different temperatures, different pH, different concentrations of chemicals, different amounts of water or oxygen or nitrogen, or more complicated acids and bases, magnetic fields and radiation. As a result, there will be a corresponding selection for more and more different molecules (69).

And here we are today, each of us a collection of atoms and molecules, each doing its individual thing:

And so on up the ladder of complexity and diversity that produces assemblies of molecules so big they become recognizable as genes, viruses, organelles, cells, tissues, organs, organisms … and us (69).

Not being a scientist myself, I can’t vouch for Rosenberg’s account of how all this works. However, it all sounds plausible to me. If you read the chapter, you will probably feel the same way.

One closing comment: people who don’t accept the fact that natural selection could eventually lead to a particular complex entity usually argue that such a thing couldn’t possibly happen. It’s inconceivable, they might say, that the human eye, which needs a bunch of parts that work together in order to work at all, could have resulted from a long series of evolutionary steps. It was Charles Darwin himself who offered the human eye as the biggest challenge to his theory. Rosenberg mentions this issue near the beginning of this chapter but doesn’t return to it. His goal in chapter 3 is to show how adaptation gets started, not how far it can go. I think, however, that it’s unwise to bet against science in its pursuit of explanations for mysterious things like the human eye or consciousness. Too many phenomena that used to be mysterious have already been explained.

In our next installment (assuming I stay sufficiently motivated): Good design isn’t just an illusion, it’s also rare, expensive and accidental.

A Guide to Reality, Part 6

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In the rest of chapter 2 of The Atheist’s Guide to Reality, Alex Rosenberg explains the second law of thermodynamics and briefly addresses some of humanity’s “persistent questions” (such as “does the universe have a purpose?”). His account of the second law is much less controversial than his answers to those big, long-standing questions.

The second law of thermodynamics is usually summed up, somewhat inaccurately, as “entropy or disorder always increases”. Rosenberg, however, begins with this description:

The second law tells us that in any region of space left to itself, differences in the amount of energy will very, very, very probably even out until the whole region is uniform in energy, in temperature, in disorder…. In our universe, the arrangement of everything goes from more improbable distributions (with more useful energy) to less improbable ones (with less useful energy). And the same goes for any self-contained part of the universe (28-31).

In other words, everything that somehow became organized will eventually fall apart (which is one reason why long-abandoned houses invariably look worse than occupied ones). An organized system is unlikely. Energy must be applied to create it and, without further energy being added to the system, it will sooner or later revert to the much more likely state of being disorganized.

Consider, for example, the atoms and molecules that make up the Eiffel Tower. It’s much less likely that they ended up being arranged in that shape than if they were randomly spread around here and there:

The most probable distribution of energy and disorder in the universe is the completely even distribution of everything….[That] is the state toward which, according to the second law, everything is moving, some places slower, some places faster, but almost inexorably. This evening-out of things – from molecules to galaxies – from less probable to more probable distributions is the rule of the universe (31).

Increasing disorder isn’t completely guaranteed, however, which is why Rosenberg says “almost inexorably”. As he explains, the second law merely means that the tendency toward disorder is extremely, extremely probable. For example, when you pour cream in your coffee, the two liquids quickly mix together. But there is nothing in the laws of physics that prohibits the cream from spelling “Good Morning” when you drop it in.

So why are there so many unlikely, highly-organized clumps of matter around (like us)? Despite what some evolution-deniers think, these clumps aren’t counterexamples to the second law. Nor are they bizarre but permissible, random bits of organization:

These are regions of the universe in which the maintenance of order is being paid for by using much more energy to produce [and maintain] the orderly things than the amount of order they produce or store. Each region of local order is part of a bigger region in which there is almost always a net increase in entropy…. Most biological order is preserved for long periods, but at the cost of vast increases in disorder elsewhere (32).

Physicists believe that the universe began in a state of incredibly extreme heat and density. Rosenberg says that this primordial state was both highly unlikely and highly organized, although “organized” might not be the best word.

If everything in the pre-Big Bang universe was evenly distributed (unlike all the molecules in the neighborhood of, for example, the Eiffel Tower), it seems odd to say that it was organized at all. It’s not as if there was some cold, thinly-populated, disorganized space different from the hot, dense stuff, waiting to be filled up. The dense stuff that existed at that point was All There Was. Unless it had some internal structure, we might as well say it wasn’t organized at all. At any rate, the universe as a whole has been falling apart (moving toward perfect equilibrium) ever since the Big Bang, despite the fact that here and there stars and galaxies eventually came to be.

Somewhat controversially, Rosenberg suggests that the second law also explains why time appears to have a “direction”:

Hard to believe, but the second law is where the direction of time, its asymmetry, comes from. It cannot come from anywhere else in physics. By process of elimination, the time order of events from earlier to later is a consequence of the second law…. None of the basic laws of physics [allow us to tell which way is past and which way is future] except for one: the second law of thermodynamics. It makes a difference between earlier times and later times: the later it gets, the more disorder, or entropy, there is (33-35).

On the other hand, another philosopher, Adrian Bardon, argues in A Brief History of the Philosophy of Time that the second law can’t explain the apparent direction of time. The second law is merely probabilistic, as Rosenberg admits. Increasing entropy is extremely, extremely likely, but not absolutely guaranteed, even for the universe as a whole. But the direction of time, if it’s real, is supposed to be unchanging, not probabilistic. Bardon concludes that the direction of time can’t be the same as the one-way, thermodynamic “direction” suggested by the second law. He thinks the fact that these two “directions” appear to go the same way is just a striking coincidence.

This brings us to Rosenberg’s brief answers to a few of those big, persistent questions. This post being so long already, however, I’ll end for now with a brief summary of his conclusions:

Where did the Big Bang come from? We don’t know, but the best current theory is that it randomly emerged from the “multiverse”. Our universe is just one of many.

Well, why is there a “multiverse” then? There’s no reason for it to exist. It just does. Get over it already!

But isn’t there some purpose to the universe? No, there isn’t any purpose to it at all.

But why then does the universe have the physical laws and parameters that allow intelligent life to exist? Given the vast number of universes popping into existence, it shouldn’t be a surprise that some of them end up being like this one. Somebody had to get a winning ticket in the cosmic lottery. It happened to be us.

In our next installment: Oh, really?

The Atheist’s Guide to Reality: Enjoying Life Without Illusions by Alex Rosenberg

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The author is a professor of philosophy at Duke University who usually writes books for other philosophers and people who aspire to be philosophers. This one was written for a general audience. Maybe that’s why the book comes on so strong. Borrowing Nietzsche’s phrase, it’s philosophy with a hammer.

I assume Professor Rosenberg chose the title, but it’s a little misleading. Rosenberg derives his atheism from a more fundamental view called “scientism”. He defines that as the worldview according to which “the methods of science are the only reliable ways to secure knowledge of anything”. Unfortunately, there is no word that refers to someone who accepts scientism except “scientist” and you can definitely be a scientist without believing in scientism. Plus, a title like The Guide to Reality for People Who Accept Scientism isn’t exactly catchy. So “The Atheist’s Guide to Reality” it is.

One way Rosenberg explains scientism is to say that physics fixes all the facts (except, presumably, for the facts of logic or mathematics). Physics says that all events in the history of the universe, except some at the quantum level, are determined by previous events and the laws of nature. Furthermore, the Second Law of Thermodynamics (entropy ultimately increases in an isolated system) is the “driving force” behind evolution, which is the result of haphazard genetic mutation. Evolution gave us minds, but our minds are nothing more than the activity of our brains.

Rosenberg concludes that we don’t have free will, introspection is generally misleading and thoughts (whether conscious or unconscious) aren’t “about” anything (since what happens in a neuron can’t be “about” anything — it’s just a tiny input/output device). Furthermore, there are no purposes in nature, even in our minds, and there are no ethical facts. Morality is just another evolutionary adaptation. In addition, we can learn nothing from history or economics, since human culture is constantly evolving.

Rosenberg expresses his conclusions with an air of almost absolute certainty, which is odd for someone who believes in science (maybe it’s not so odd for someone who believes in scientism). For example, he says that “what we know about physical and biological science makes the existence of God less probable than the existence of Santa Claus”. Perhaps he’s being facetious in that passage, but many atheist or agnostic philosophers would agree that God’s existence is a metaphysical question beyond the reach of science. Natural processes don’t count for or against the supernatural. Besides which, there is no evidence at all for the existence of Santa Claus.