Science Thursday- I respond to ‘New Physics Theory of Life?’ in Quanta Magazine

For my “Science Thursday” post, (which I’m reprinting here) I responded to an article entitled “A New Physics Theory Of Life” which you can read in Quanta Magazine (link below). This was in a paper , a technical paper that was published in J.A.Phy by Jeremy England from MIT labs.

Here’s an excerpt from Quanta:
‘Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula …The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.

At the heart of England’s idea is the second law of thermodynamics, also known as the law of increasing entropy or the “arrow of time.” Hot things cool down, gas diffuses through air, eggs scramble but never spontaneously unscramble; in short, energy tends to disperse or spread out as time progresses.’
This is what I wrote in response:

If it is true that chemical systems will, as claimed here, progress towards more energetically dissipative states, that would be a real finding, let alone one that’s relevant to the origin of life.
There are really two responses I can think of to the paper, one chemical or ‘experimentally’ based, the other is more theoretical. If the paper’s theory holds, then I would expect to see some new chemistry presented, at a very basic level. Chemical systems that tend to dissipate heat are known as chemical systems, that is what molecules do when they combine. These are exothermic (give off heat) or endothermic (absorb heat).
If, it’s true that a system will become complex because it tends toward a dissipative one, then my question would be, OK are the molecules of DNA and proteins in an organism at the most dissipative level? Because, intuitively I’d say they’re not. And that’s because they are not at their lowest energy state possible, meaning no more energy can be absorbed, and thus maximum energy would be dissipated. The molecules in an organism are not in this state at all- plants are a very good example of this, as they are a high source of energy but also heat for homes. So plants have plenty of energy that’s not dissipated, or dissipating, in fact they are energy stores, they are food. There is more work to show how these theoretical systems would be achieving ‘maximal dissipation of energy’. And as far as examples of actual chemistry goes, the paper doesn’t show any new chemistry that I can see, in other words it doesn’t show what these ‘theoretical systems’ might look like.

The second point, is theoretical. In short, the paper begins with the premise that reversing entropy is like “unscrambling eggs,” and we all have an intuitive sense of what entropy is. And yet, we are to imagine that given enough time, or with long enough energy input, the egg will “unscramble itself?” I wanted clarification on that point, but unfortunately the paper itself, which I’ve read, is unclear on this conclusion. So I’m frankly not really sold on the notion that “if you shine light long enough on atoms, it forms a plant,” which I assume means a thousand million years or so.

Here’s more from Quanta: ‘This principle would apply to inanimate matter as well. “It is very tempting to speculate about what phenomena in nature we can now fit under this big tent of dissipation-driven adaptive organization,” England said. “Many examples could just be right under our nose, but because we haven’t been looking for them we haven’t noticed them.”

Yes, but actually these examples of such systems already exist, they are natural processes that dissipate vast quantities of energy, achieving maximal energy dissipation for the given physical parameters. They are called alluvial fans, and include phenomenon such as erosion patterns in mountain sides, ripples in the sand, and cracked mud. Basically put, rivers ‘figure out’ how to run faster downhill by widening their channels thereby lowering resistance.
Adrian Bejan, a physicist from Duke, described (American Scientist 2006) a theory he called “constructal theory” to account for these natural processes of energy dissipation and how they correlate to the movements of animals through water, across land, and through the air. “Optimization is an old idea and an even older natural phenomenon.”
It’s an interesting theory, which might have intriguing applications to new science, but I’m hoping that there can be some clarification as to what it is actually saying regarding the second law and how this might be different from other ‘optimization’ theories already in existence.

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