Is there a second arrow of time? New research says yes

You may be familiar with the “arrow of time,” but did you know there may be a second one?

Dr. Robert Hazen, staff scientist at the Carnegie Earth and Planetary Science Laboratory in Washington, DC, thinks that a single arrow of time can be too restrictive. A second arrow, which he calls “the law of increasing functional information,” takes evolution into account. Specifically, Hazen explains that evolution seems to involve not only time, but also function and purpose.

Consider a coffee mug: it works best for holding your coffee, but it can also function as a paperweight and wouldn’t work as well as a screwdriver at all. Hazen explains that it appears the universe uses a similar way to evolve not only biology, but other complex systems throughout the cosmos.

This idea suggests that as the universe ages and expands, it is becoming more organized and functional, almost the opposite of theories about increasing cosmological disorder. Hazen suggests that these two “arrows”—one of entropy and one of organized information—could very well go hand in hand. If true, this theory could be groundbreaking in the way we perceive time, evolution, and the very fabric of reality.

Robert Hazen: I have a confession to make here. I have to be honest. We could be wrong. We can be spectacularly wrong. But it’s also possible that science is missing a deep truth about the cosmos. We have these 10 or so laws of nature, only one of which currently has an arrow of time. This is the second law of thermodynamics, the increase of entropy—is disorder; it’s a breakdown.

We all get old. We all die. But the second law does not explain why things evolve; why life emerges from non-life. You look around and see flowers blooming and trees blooming and birds singing. It seems like all these things are at odds with the idea of ​​disorder. In fact, it is a kind of regulation of nature.

So let me tell you what we think: We think there is a missing law, a second arrow of time that describes this growth in succession, and we think it has to do with an increase in information. So there are two possibilities. We could just be wrong. We could be horribly, dramatically wrong. But I think, if we’re wrong, we’re wrong in a very interesting way. And I think that, if we’re right, it’s deeply important.

I’m Bob Hazen. I am a Staff Scientist at the Carnegie Earth and Planetary Science Laboratory in Washington, DC. I do mineralogy, astrobiology. I love science. We think that, for some reason, a second arrow of time was missing. And this arrow is about an increase in information, an increase in order, an increase in patterning that goes hand in hand with the arrow of increasing disorder and increasing chaos, entropy.

The essence of everything we have thought about, in terms of the missing law, is evolution. When I say the word “evolution,” you immediately think of Darwin, but this idea of ​​selection goes far, far beyond Darwin and life. It applies to the evolution of atoms. It applies to the evolution of minerals. It applies to the evolution of planets, atmospheres and oceans. Evolution, which we see as an increase in diversity, patterning, complexity of systems over time.

And so the question is, “Well, what is evolution?” Evolution is simply selection for function. And this applies to any type of system. Now, in life, you select for organisms that can survive long enough to reproduce and have offspring that will pass on their characteristics. This is what Darwin said, and this is a very important example of selection for function. But in the mineral world, you choose for organizations, assemblies, structures of atoms that persist, that can last billions of years even in new environments.

They don’t break. They do not dissolve. They do not leave the weather. It is very analogous to biological evolution, but is different in detail. We think there is a law missing – it is a law of evolution. And, if there is a law, it must be quantitative. There must be a metric. You have to be able to measure something. And what we zero in on is a fascinating concept about information, but not just information in general, something called ‘functional information’.

Let me see if I can explain this to you because it took me a while to figure it out myself. Imagine a system, an evolving system that has the potential to form a large number of different configurations. Let’s say they are atoms to make minerals, and you have dozens of different elements that form minerals, and they can be arranged in different ways. And 99.99999999—I could go on—percent of these setups won’t work. They will fall apart. They will never be formed. A small, tiny fraction creates a stable ore, and you end up with some stable ore and a lot of rejects.

Now, all you have to do is think about that fraction. If it’s a one in a hundred trillion, trillion, trillion, trillion chance that it’s stable, then you can represent that part as information. And because it’s such a small, tiny fraction, you need lots of pieces of information to do that—that’s functional information. Evolution is simply an increase in functional information because, as you select for better and better outcomes, you select for minerals that are more and more stable. You choose for creatures that can swim. They can fly. They can see.

You need more information, and each step of the evolutionary ladder leads you to increasing functional information. So our law, our missing law, the second arrow of time is called ‘The Law of Increasing Functional Information’. And this is the parallel arrow of time that we think is there and we want to understand it. The idea of ​​increasing functional information has a really deep implication. Think of the functional information of a cup of coffee; you can wear one now.

You have a bunch of atoms, and those atoms can be in trillions and trillions and trillions of different configurations, but only a small fraction of those configurations will hold a cup of coffee. Now, think of a cup of coffee as a paperweight. I know you used a coffee cup as a paperweight. We all have, and it’s very good at it, but you can make a better paperweight. And a cup of coffee makes a terrible screwdriver. So think about it: we’re saying that a cup of coffee is worth a cup of coffee. It has some value as a paperweight, but no value as a screwdriver – that’s contextual.

So this is why the second arrow of time is difficult for science, because it says that there is something in the natural world that is not absolute. It’s contextual. It depends on what your goal is. It depends on your function. If it is true, what we are saying is that there is something in the Universe that is increasing order, it is increasing complexity, and it is not doing so randomly. It is selecting for function. And if it is, if you’re choosing for function, it means that it almost seems to have – can I use the word “purpose?”

Do minerals have a purpose? Do atmospheres have a purpose? Does life have a purpose? To me, there is something real there, and the old way of thinking about a single arrow of time doesn’t ring true to me anymore.