You may know the “Arrow of Time,” but did you know there might be a second one?
Dr. Robert Hazen, a scientist at Carnegie Science’s Earth and Planets Laboratory in Washington, DC, believes that a single arrow of time may be too limiting. A second arrow, which he calls “the law of increasing functional information,” takes evolution into account. Specifically, Hazen explains that evolution seems to encompass not only time, but also function and purpose.
Consider a coffee cup: it’s best suited for holding coffee, but it could also serve as a paperweight and would be completely useless as a screwdriver. Hazen explains that the universe appears to use a similar way to evolve not only biology but other complex systems throughout the cosmos.
This idea posits that the universe becomes more organized and functional as it ages and expands, which is almost the opposite of theories that speak of increasing cosmological disorder. Hazen suggests that these two “arrows” – one of entropy and one of organized information – may well run parallel to each other. If this theory is correct, it could bring about groundbreaking changes in our perception of 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 could be spectacularly wrong. But it’s also possible that science is missing a profound truth about the cosmos. We have these 10 or so laws of nature, and currently only one of them has an arrow of time. That’s the second law of thermodynamics, the increase in entropy – that’s disorder, that’s decay.
We all grow old. We all die. But the second law does not explain why things evolve; why life arises from non-life. You look around and see flowers blooming and trees blossoming and birds singing. It seems like all of these things contradict the idea of disorder. In fact, it is a kind of order of nature.
So let me tell you what we think: We think there’s a missing law, a second arrow of time that describes this increase in order, 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 wrong, dramatically wrong. But I think if we’re wrong, we’re wrong in a very interesting way. And I think if we are right, it is of great importance.
I’m Bob Hazen. I’m a scientist at the Earth and Planets Laboratory at Carnegie Science in Washington, DC. I do mineralogy and astrobiology. I love science. We believe that for some reason there is a second arrow of time missing. And that arrow has to do with an increase in information, an increase in order, and an increase in pattern, going side by side with the arrow of increasing disorder and increasing chaos, entropy.
At the core of everything we’ve been thinking about in relation to the missing law is evolution. When I say the word “evolution,” you immediately think of Darwin, but this idea of selection goes way 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 we think of as an increase in the diversity, patterning, and complexity of systems over time.
So the question is, “What is evolution?” Evolution is simply functional selection. And that’s true of all kinds of systems. In life, you select for organisms that can survive long enough to reproduce and have offspring that pass on their characteristics. That’s what Darwin said, and that’s a very important example of functional selection. But in the world of minerals, you select for organizations, assemblies, and structures of atoms that persist and can survive even in new environments for billions of years.
They don’t decay. They don’t dissolve. They don’t weather. This is very analogous to biological evolution, but in the details it’s different. We think there’s a law missing – it’s an evolutionary law. And if there is a law, it has to be quantitative. It has to have a measurable value. You have to be able to measure something. And we’ve focused on a fascinating concept about information, but not just information in general, something called “functional information.”
Let me try to explain it 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 huge number of different configurations. Let’s say it’s atoms that make minerals, and you have dozens of different mineral-forming elements that can arrange themselves in all sorts of ways. And 99.99999999 – I could go on – percent of those configurations are not going to work. They’re going to fall apart. They’re never going to form. A tiny fraction of them will make a stable mineral, and you end up with a few stable minerals and a lot of scrap.
Now all you have to do is think about that fraction. If it’s one in a hundred trillion, trillion, trillion possibilities that is stable, then you can represent that fraction as information. And because it’s such a tiny fraction, you need a lot 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 minerals that are more and more stable. You select creatures that can swim. They can fly. They can see.
You need more information, and each step up the evolutionary ladder takes you to more functional information. So our law, our missing law, the second arrow of time, is called the Law of Increasing Functional Information. And that’s the parallel arrow of time that we believe is out there and that we want to understand. The idea of increasing functional information has a really profound meaning. Think about the functional information of a coffee cup; you might be holding one in your hand right now.
You have a lot of atoms, and those atoms could be in trillions of trillions of trillions of different configurations, but only a tiny fraction of those configurations would hold a cup of coffee. Now imagine a coffee cup as a paperweight. I know you’ve used a coffee cup as a paperweight before. We’ve all done that, and it’s pretty good at it, but you can make a better paperweight. And a coffee cup makes a terrible screwdriver. So think about it: we say that the coffee cup has value as a coffee cup. As a paperweight it has some value, but as a screwdriver it has no value — that’s contextual.
That’s why the second arrow of time is difficult for science, because it says there’s something in the natural world that is not absolute. It’s contextual. It depends on what your purpose is. It depends on what your function is. If that’s true, we’re saying there’s something in the universe that increases order, increases complexity, and it doesn’t do it in a random way. It selects by function. And if that’s the case, if you select by function, that means it’s almost like — can I use the word “purpose”?
Do minerals have a purpose? Do atmospheres have a purpose? Does life have a purpose? To me, this is something real, and the old way of thinking that there is only one arrow of time no longer sounds right to me.