The last question was asked for the first time, half in jest, on May 21, 2061, at a time
when humanity first stepped into the light…
(man asks) “How can the net amount of entropy of the
universe be massively decreased?”…
(computer responds) “INSUFFICIENT DATA FOR MEANINGFUL ANSWER”
–“The Last Question” 1956, A short story by Isaac Asimov
I keep waiting for an engineer at Amazon to program Alexa with that response.
Isaac Asimov was a professor of biochemistry at Boston University. Many consider him the greatest science fiction writer of all time. He falls under the genre of “hard science fiction” in that most of his literary inventions have an underlying physical-chemical mechanism, requiring minimal magic. One of Asimov’s triumphs is “The Foundation Trilogy”. Asimov’s “I-Robot” was pioneering for the field of artificial intelligence and proposed seminal rules for robotic interactions with society.
Asimov’s personal favorite piece “The Last Question” is a short (~20 minute) story focusing on a key result of the laws of thermodynamics that is a philosophical hallmark of our existence: how will the Universe, and humanity, end? Conversely, if thermodynamics can explain that, then the natural extension is to question what the laws of thermodynamics say about humanity’s beginning. Obviously, these are controversial topics closely tied to religion and, as a forewarning, I’m agnostic to the God debate. This is only about the laws of thermodynamics. Why those are the laws of the universe is an entirely different debate.
What your view of the 2nd Law says about you
The common interpretation of the 2nd Law of Thermodynamics is that the entropy of the universe always increases. Entropy is often synonymous with disorder. I often use the example of my garage or office to introduce the concept of entropy — I start work in a very orderly workspace, as work is done, things become disordered, and eventually it becomes difficult to do any more work.
The concept of the 2nd Law of Thermodynamics, and a limit to the amount of work you could produce, was developed in the early 1800’s by Saudi Carnot while trying to make a better steam powered locomotive. In this instance, entropy was waste, the thing limiting the power of an engine, inefficiency. And you can’t get away from it. Entropy happens in all processes, whenever a potential gradient for energy is acted upon. When you consider engineering as about reliability and control, it’s easy to understand why most of us view entropy in such a limited and dismal way.
On a personal level, one could come to the conclusion that we have a limited amount of useful energy and need to carefully limit our entropy generation. The legend is that one of the pioneers of entropy moved to Egypt and wore thick coats to minimize entropy generation through exchange of heat… only to die of kidney failure as a result of dehydration.
To make matters worse, in the 1850’s, William Thomson a.k.a. Lord Kelvin, applied the concept of entropy to the Sun and the universe. Kelvin was concerned about the lifetime of the sun. His theory, that the entropy increase of the sun and universe would dissipate all energy gradients until nothing could exist, became known as the “Heat death of the universe“. The time frames on which this would occur varied greatly. If you assume the sun is some kind of chemical fire burning in space — we don’t have much time, may’be 100’s of years. There are hypotheses that the Third Reich used this knowledge as justification for attempts to rule the world in light of the limited time we had left. The discovery of nuclear processes and radiation extended the eventual heat death many, many orders of magnitude, something like 10^100^100 years. That said, the concept of Heat Death isn’t going away any time soon, which was why Asimov was able to use it as the mechanism for his story.
From these origins of law, power, and control, entropy and the 2nd Law of Thermodynamics was anointed the evil limiter of power and progress. “This is the way the world ends, not with a bang, but a whimper.” -T.S. Eliot. Sigh…
Think about it another way. What if Saudi Carnot really had succeeded in developing a perfectly efficient, zero entropy generation steam engine? Or for that matter, what if Nature had evolved a perfectly efficient horse? Would everyone still be riding horses?
What if entropy never caused us to age? Would neanderthals have overpopulated the earth millennia ago?
Without entropy, would the earth have been overran by the first algae that sprang from the primordial goo?
Can life even exist without entropy?
What you can see is entropy, contrary to those concerned with power and control, may be the very virtuous property that governs sophistication versus evolution to new and un-imagined ways of being. How you look at entropy says a lot about how you look at the world and what you are valuing at the particular moment. Context is essential. Entropy can be a very wonderful and disastrous thing, at the same time.
Life(?) in the Energy Cascade
“Big whirls have little whirls that feed on their velocity, and little whirls have lesser whirls and so on until viscosity.”
— Lewis Richardson
We’re going to start this at the bottom and work our way up. Life exists in many sizes and ways throughout the universe. If the Laws of Thermodynamics were not independent of scale, they wouldn’t be physical law. In recent years, the “Quantum Thermodynamics Revolution” is attempting to merge the fields of quantum mechanics and the 2nd Law. Quantum mechanics is mirroring, something; up or down, connected or not. Go back to my garage example. Instead of looking at the resulting mess as disorder, think about it as a puzzle or crime scene. The tools and parts lying around are connected and tell an important story of what happened. In quantum mechanics this is known as “entanglement” — the state of one particle cannot be described independent of others. Context, path, and history now matter. The more ways a particle is entangled, the higher the entropy. The more entangled a particle becomes with others, the more story it has to tell, and the more difficult it is to control or predict the outcome.
Entropy, at the atomic scale, is closely related to viscosity due to the ways entanglement can occur. As Lewis Richardson’s poem above alludes, when turbulent eddies become sufficiently small, momentum is dissipated as thermal energy, which is directly related to entropy. Recent attempts to predict transport properties, like thermal conductivity and viscosity, from traditional thermodynamic properties have focused on density and residual entropy as key model inputs. Once in the viscous realm, the properties of the fluid, like viscosity, help determine the spectra of turbulent eddies that will emerge from an event.
Jupiter’s Great Red Spot is a hurricane eddy of epic proportions — 1.3 times larger than the diameter of the entire earth! Think about the scale of energy dissipation. The Great Red Spot is believed to have spontaneously emerged around 200 years ago and is slowly shrinking. The stability of the storm is impressive. Go whitewater rafting on a river and you’ll see stable eddies of impressive proportions, but those are just yearly and ebb with the flow. The question becomes why these eddies remain so stable for as long as they do. The answer comes from the dominant energy drivers that create the eddies in the first place. If the energy flows are similar, you’ll get similar behavior. Neptune has it’s own giant spot.
I was in Norway earlier this year presenting some of my hydrogen work. During a hike outside of town I began noticing similar plants — pines, alders, service berry, elderberry, in similar places as my home in the Pacific Northwest. The geology and weather of Norway and the Pacific Northwest have very similar geographical position relative to the ocean currents that drive weather patterns. It makes sense that the energy flows are very similar. As this thought emerged I noticed a neat grassy hump nearby and thought that if it was in the Pacific Northwest a robin would be searching for worms on that spot. A moment later a yellow and brown bird flew down, hopped like a robin, then grabbed a worm. The structures of the flow and the energy cascade created the opportunity for a bird of that size and behavior, but did not dictate the color, which is likely a cultural thing.
Definite analogies exist between the cascades of physical structures and biological organisms. Differentiating between the two is important. In 2014, MIT Biophysics Professor Jeremy England made a radical hypothesis: life spontaneously emerges due to thermodynamics. “You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant,” said England for Quanta magazine. England’s simulations have shown that when you take a random assortment of chemicals, and provide external forcing functions (think electrical charge, momentum, thermal gradients) to the system, self-organizing structures emerge somewhere in the system that self-optimize for entropy generation. England set up the traditional Gibbs Energy to promote a phase change conducive to life-based organisms. Whether this is indeed life, or simply a physical structure like the Great Red Spot, is still in debate. Science writer Philip Ball ran with the concept and published an inspiring piece “How Life (and Death) Spring from Disorder“.
NASA has had to devote considerable effort to this debate in order to decide what could be considered a living organism or artifact thereof. What is clear is that anything that could be considered living must take in energy and transform it in some way for growth and reproduction. In that moment something magical must happen — the ‘organism’ must concentrate energy (decrease entropy) and go against the 2nd law of thermodynamics that states energy must diffuse towards disorder (increased entropy). But we all realize quickly that life, once it multiplies and manifests, tends to lead towards faster entropy production than what would’ve happened without life there to begin with. In other words, life, or the concentration of energy by organisms, emerged as a way to increase the entropy of the universe even faster.
When Structure Becomes Life and Society
With enough self-organizing, entropy producing, structures spontaneously emerging in the history of our planet, it’s only natural that at some point it became advantageous from thermodynamic law for these structures to self-replicate. With enough self-replicating structures, it’s only natural that at some point it becomes advantageous from thermodynamic law for the next step to be Darwinian evolution — how NASA broadly defines the criteria for life. With enough time, to further maximize the entropy production potential, organisms became aware of self and others. Hence an aware organism asked the first question, “why am I?” Thus leading to the last question, “why must it end?”
Somewhere in that progression empathy emerged. Just like the entanglement of quantum particles, organisms became entangled. A plant emerged with something like a flower that attracted insects that helped replication. Plants and animals developed an ever more entangling reliance on others until a cascade of life-forms emerged. At some point a plant emerged with a flower so beautiful that something called a human said it would replicate this plant all over the planet. At some point the human decided the flower represented what they called a culture.
We spontaneously emerged. Given the random chain of events and required conditions, it was inevitable, and exceedingly rare. Now we, as a culture, are asking ourselves how long we can keep it going.
Sociology Professor Kenneth D. Bailey in his book “Social Entropy Theory” used traditional thermodynamic arguments to conclude that society was doomed to chaos. Physical Chemist, and former president of Illinois State University, Thomas P. Wallace’s book “Wealth, Energy, and Human Values: Dynamics of Decaying Civilizations from Ancient Greece to America,” took a similar dismal view. Looking around at the problems of contemporary society it’s easy to take such a view. Neither made the connection of entropy as empathy, nor the role these play in sophistication versus evolution. Is the end of civilization possible? Absolutely. Just like the heat death of the universe argument, our future is only dire until we realize the new possibilities and ways we couldn’t see before. Show me an academic, and I’ll likely show you someone consumed with power and control. But as we’ve seen, that’s a very, unnecessarily, dismal view of entropy.
Empathy, likely a form of entropy itself, emerged to promote entropy production. Empathy, unlike purely structural/physical entropy, entangles us in the chemistry of what we call culture. Entropy can be a very beautiful thing. When we really understand entropy and empathy, may’be we’ll finally be ready for Asimov’s ultimate last question.
(Note: this post is one chapter of what could become a book someday. The other chapters can be found here: https://hydrogen.wsu.edu/dr-jacob-leachman/ )