March 6th, 2026
I am often frustrated by articles about life on other planets. Authors dig for every possible scrap of information that might somehow support a reader’s hope that there’s life somewhere out there. That’s what people want to see and there are plenty of authors out there who are happy to give them what they want.
Well, I’m here to pee all over those hopes. No, I’m not going to tell you that there can’t be any life out there. Instead, I’ll be presenting some basic concepts that will bring some order to the chaos of claims out there.
The first thing you need is a clear understanding of the very notion of living systems. If you enter the search phrase “What is life?” into any search engine, you’ll find a ton of definitions and descriptions — most of which are wrong. Most of the definitions I have seen mention reproduction, which is NOT fundamental to life. Many definitions talk about “biochemical reactions”, which again are not fundamental. Many more talk about the role of water as “the universal solvent of life” — but water is not necessary to life.
So let’s step way back to think about what life really is, at the most fundamental level. My first observation is that life “does things”. Every living system must have some internal processes that do things. Rocks aren’t alive. Living things are systems of processes.
My second observation is that living systems continue. They persist. If a living system stops its processes, we say that it is dead — not alive any more. So the systems that constitute life must persist for it to meet our definition.
Now, the fact that a living thing is a system of processes leads directly to the conclusion that it must have some sort of orderliness. Moreover, that orderliness must persist; if it is lost, then the orderly processes stop and the system is no longer alive.
Enter the Second Law, twirling its mustache
The Second Law of Thermodynamics is the villain of this piece. I won’t drag you through the thermodynamics theory required to properly understand the Second Law — it is simultaneously confusing and boring.
The gist of the Second Law is that real-world systems always eventually fall apart. The central notion of the Second Law (and the concept that people just can’t get down their craw) is called “entropy”. The best civilian synonym for ‘entropy’ is ‘disorderliness’. Some examples might help you understand entropy.
Disorderliness is akin to ‘messiness’. A teenager’s room is usually messy, or disorderly — it has high entropy. After a parent intervenes and orders the teenager to clean up the mess, the entropy of the room is reduced.
A bunch of coins thrown onto the floor have high entropy. Some are heads-up, some are tails-up. But if somebody flips over the tails-up coins, so that they are all heads-up, they reduce the entropy of the set of coins.
Let’s get personal. Consider all the atoms in your body. They are exquisitely organized into a magnificent system of extreme orderliness. Your body has extremely low entropy. If somebody messes it up by, say, putting it through a wood chipper, then the organization of the atoms is messed up and the atoms are scattered around willy-nilly. That’s much higher entropy. Oh, and you’re dead, too.
The Second Law says that no system ever loses entropy; the entropy of any system must always either stay the same or increase. In other words, a system just naturally loses order over time. Now, the Second Law doesn’t specify how rapidly a system loses order. Some systems, like little bits of rock floating in interstellar space, lose order very slowly. Other systems, like a feather thrown into a furnace, lose their order quickly.
This means that the Second Law is the enemy of life. The Second Law is the fundamental force of Death. A living system left to itself must eventually lose enough of its orderliness that it dies.
Now I’m going to turn my nomenclature upside down. Entropy is disorderliness; the reverse of entropy is orderliness, and we call that “negentropy”. It turns out that the discussion is easier to understand if we talk in terms of negentropy (orderliness).
Therefore, and this is an immensely important concept, every living system must stave off the depredations of the Second Law by somehow collecting negentropy.
Whence cometh negentropy?
Here’s where we stand: living systems are highly organized; that is, they have lots of negentropy. But the Second Law is constantly increasing the disorderliness of every system; it is destroying negentropy. Therefore, every living system must come up with a scheme for replacing the negentropy destroyed by the Second Law.
Where can living systems find negentropy? That’s not an easy question to answer, because negentropy is not a substance like water or gold. It’s not energy, either — but energy can carry negentropy.
“Huh?” you say. “How can energy ‘carry’ negentropy? What does that mean?”
You are being confused by the abstract nature of negentropy. It’s not something you can see, touch, smell, hear, or otherwise sense. It’s like ‘honor’ or ‘love’ or ‘truth’ — it’s an abstract concept that is absolutely real but not palpable. Here’s one way of thinking about negentropy. Consider this item:
Ah yes, money: something real, something useful. You can put your hands on money, you can stuff it into your pocket.
You like money because it’s valuable. But hold on: the money itself isn’t intrinsically valuable. You can’t eat it; you can’t wear it; you can’t play video games with it. Money in and of itself is useless.
The value of money is that it’s, well, valuable. Money isn’t intrinsically valuable; it represents value. Money carries value the same way that energy carries negentropy.
The proof that money only carries value comes from inflation. When I was a kid, I could use that dollar bill to buy a double-decker hamburger with fries and a milkshake. Nowadays the same meal would cost me about $12. The value of that dollar bill has changed. Ergo, the money’s value isn’t constant; the value lies not in the money itself but in what it represents.
In much the same way, energy is a carrier for negentropy, but it is not in and itself negentropy. Here’s an illustration of the idea in a gif showing an internal combustion engine working:
4-Stroke-Engine.gif: UtzOnBike (3D-model & animation: Autodesk Inventor) derivative work: Cuddlyable3 and Jahobr, CC BY-SA 3.0,
Now, the moment of truth comes when the spark plug ignites the gasoline-air mixture above the piston and it suddenly become very hot, as indicated by the fact that it turns red. That’s what pushes the piston downward, an event called the “power stroke”. That’s what makes the engine go. But ask yourself, ‘Why does the hot gas push the piston downward?’ Well, the gas is very hot and therefore has high pressure, and that pressure is what drives the piston down.
There’s a catch: there is also air underneath the piston, and that air has pressure, too. But the air underneath the piston is at a much lower temperature, and so has much less pressure than the red-hot gas above the piston. The fact that the gas above the piston has greater pressure than the gas below the piston is what drivers the piston downward.
But what if the engine were operating inside a furnace, so that the air underneath the piston was just as hot as the gas above the piston? Then the pressures would be the same and the piston wouldn’t move. The engine wouldn’t work at high temperatures. In other words, it’s the DIFFERENCE in temperature between the burning gas and the air that makes the engine work. That difference is the basis for the negentropy. Internal combustion engines can work only because our planet is cool, but burning gas is hot. The energy of the gasoline is only half of the equation; the other half is the coolness of the air. Energy is not negentropy.
SO WHAT?!?!?!
This has been a long piece and I’m just getting started. Now I have to explain the significance of all this theoretical nonsense about negentropy. I can use the concept of negentropy to compose a more useful and more meaningful definition of life. Here goes:
A living system harvests negentropy in a manner that permits its indefinite continuation.
A fine point: before you pounce on the fact that all living creatures on earth eventually die, don’t forget that they reproduce. You’re thinking in selfish terms, only about yourself. Your species is the living system, not you, and it does indeed behave in such a manner as to permit its indefinite continuation.
To put it in simpler terms, all living systems feed on negentropy to continue living. The four sources of negentropy on earth are, in order of importance:
Sunlight: This is the greatest source of negentropy for earth. If you think in terms of temperature differences, the sunlight is at an “effective temperature” of 5800ºK, while the plants that harvest the sunlight are at a temperature of about 300ºK. That’s a 5500ºK temperature difference! That makes for a lot of negentropy!
Herbiage: This is the stuff that plants make from all that sunlight. They use the negentropy of the sunlight to build complex organic molecules that allow the plants to grow larger. That complexity is a form of negentropy. Lots of animals (e.g., grasshoppers, cows, people) eat the plant material to absorb its negentropy; their digestive systems chemically alter the plant molecules into molecules that the animals use to build their own bodies.
Meat: Just as herbivorous animals harvest the negentropy of plants, carnivorous animals harvest the negentropy of other animals. Their digestive systems are a little different, but they convert the complex molecules of their prey into the molecules they need to build their own bodies.
Geochemicals: A number of interesting oddities have been found deep underwater. The most striking of these are “black smokers” or “hydrothermal vents”. These are locations on the deep ocean floor where magma comes close to the surface. Sea water seeps down into the hot rocks, is heated, absorbs lots of minerals, and is ejected upwards.
The dense chemicals can be used by living creatures to drive chemical reactions that in turn support the biochemical processes the cells need. Other, more conventional animals then eat the oddball cells, and an entire ecosystem builds up around the black smoker. Variations on this scheme have even been found deep in subsurface lakes in Antarctica.
Other sources of negentropy
These four sources of negentropy drive life on earth; elsewhere there may be others. Obviously, starlight can be just as effective anywhere as it is on earth. There are, however, two important factors to take into account. First is the simple matter of the intensity of starlight. For example, Mars is 50% further away from the sun than the earth. Accordingly, sunlight on Mars is only 44% as strong as it is on earth. Sunlight at Jupiter’s distance is less than 4% as strong as on earth, and at Uranus’ distance, it’s only 0.3% as strong. Don’t count on sunlight being a significant source of negentropy beyond the orbit of Mars.
But there’s another factor at work: the availability of a complex mechanism capable of generating a system that can harvest negentropy. Mercury is so close to the sun that the negentropy it receives from the sun is 660% greater than that of earth. Wow! That should feed a magnificent biosphere, right? Sadly, there’s a problem: the side of Mercury that faces the sun is just rocks. There’s nothing that can perform complicated operations to process the sunlight. So all that negentropy goes to waste. Dirty ricklefricks!
On earth, we have organic chemistry to provide the mechanisms for harvesting the negentropy of sunlight. Organic molecules (composed of carbon, hydrogen, and a smattering of other elements) can combine in zillions and zillions of ways. A typical protein inside a cell has about 8,000 component atoms. By comparison, the largest Lego set has about 11,000 bricks. Imagine how much negentropy it takes to assemble thousands and thousands of such proteins to get a minimally living cell. Organic chemistry strikes me as a particularly clumsy mechanism for building living systems. Have you ever seen how the Krebs Cycle works? See https://en.wikipedia.org/wiki/Citric_acid_cycle. In order to assemble a sentient being with organic chemistry, you need to put together about 10**28 atoms. That’s 10,000,000,000,000,000,000,000,000,000 atoms. Gadzooks!
So, if you want to find life elsewhere in the universe, you’ll need two things: a big source of negentropy, and a physical phenomenon that can be used to assemble complex systems. Where, oh, where might we find this combination?
Obviously, stars are the biggest source of negentropy in the universe; our own biosphere was built from less than one 2 billionth of the negentropy emitted by the sun. Gee, if the sun generates 2 billion times more negentropy than the earth intercepts, do you think that it might be a good place to look for life?
Oh, wait — it’s really hot in the sun. Much too hot for organic chemistry — or any chemistry, for that matter. It’s so hot in the sun, that the atoms are all stripped of their electrons and could not possibly hold together in the intense heat.
Wait again: do you really believe that chemistry is the only complex system in the universe? Have you never heard of magnetohydrodynamics? This is the field of physics that deals with the behavior of plasmas. See https://en.wikipedia.org/wiki/Magnetohydrodynamics. Scroll through that page and savor the mathematical equations.
Heh, heh, heh. And you thought that organic chemistry is complicated! We’ve learned a lot about magnetohydrodynamics because that field is the key to getting fusion reactors working. To put it more succinctly, magnetohydrodynamics is the reason why, after working on the problem for more than sixty years, we STILL don’t have working fusion reactors.
Inside every star, we have stupendous amounts of negentropy, and a physical mechanism capable of complexity that boggles the minds of the most brilliant physicists. If life on earth could be built with piddling amounts of negentropy and a clumsy mechanism like organic chemistry, do you really doubt that life could not form inside a star?
Of course, the star-sized hole in my proposal is that we simply don’t know how magnetic fields operate inside a star. We know lots of basic principles, and we’ve got some good measurements of magnetic behavior at the surface of the sun, but ask an astrophysicist what the magnetic fields inside the star are doing, and you might just get an answer in a few centuries.
Now let’s get technical
(You might want to skip this section)
There’s a thin zone inside every star called the tachocline. This is a region of particular relevance to the possibility of life. To understand its significance, you’ll need to understand energy flow in a star. The fusion reactions that generate its energy all take place in the core at the center of the star. Those fusion reaction release high-energy particles of light called gamma rays, or photons. Each photon travels at the speed of light, but the material inside the sun is so dense that it doesn’t get very far before it hits an atomic nucleus. It bounces off that nucleus, losing a little energy, and heads off in a new direction until it hits another nucleus, and so on and so forth. There are so many collisions that it takes the average photon about 100,000 years to make it all the way to the surface of the sun. As the crow flies (assuming the crow is indestructible), it’s only 700,000 kilometers from the core to the surface, and the photon would take a bit over two seconds to get there. But there are so many collisions that it takes 100,000 years, during which time the photon travels 100,000 light-years. Our solar photon could cross the galaxy in that much time — if only it could shake itself free of all those crowded nuclei.
This process is called “radiative transfer” because it uses radiation (the photon) to transfer energy from the core to the surface. But there’s another form of energy transfer that’s important here: convective transfer, which happens when hot matter moves and therefore carries its heat somewhere else. When you feel the warmth of the sunshine on your face, that’s radiative transfer; when a hot wind blows in your face, that’s convective transfer.
Now, radiative energy transfer is highly efficient when it’s done with super high-energy gamma ray photons. But as gamma ray photons elbow their way out of the core, they keep losing energy from all those collisions. The more collisions they experience, the weaker they become, until, at a certain point, they’re just not transferring enough energy. At this point, more energy is being transferred by the rising motion of the atomic nuclei. The region where this transition takes place is called the “tachocline”, and the tachocline is characterized by maximum negentropy accumulation. If there really is life inside a star, the tachocline is where it would most likely be found.
But that’s only half the story. The other half is the magnetohydrodynamics that I think could generate immense complexity. Now I will vent my own personal hot air about how I think that could happen.
The sun is composed of plasma. Not blood plasma, silly; physics plasma. Physics plasma is a gas that’s so hot that all the atoms smash into each other with so much energy that they knock loose all of the electrons on each atom. Thus, a physics plasma consists of lots of positively charged atomic nuclei and lots more negatively charged electrons. (Actually, it’s more complicated than that, but this simple generalization is sufficient for me to make my point.)
So inside a plasma there are lots of charged particles (both positive and negative) moving around really fast. When a charged particle moves, it generates a magnetic field. On top of this, a magnetic field causes charged particles to veer in another direction. Hence, the magnetic field made by one moving charged particle will change the course of another moving charged particle, while the magnetic field caused by the second moving particle will cause the first one to change its course. If you find that confusing, let’s make it a LOT worse by noting that there are zillions and zillions of these charged particles, some positive and some negative, all moving around very fast, with all their magnetic fields changing each other’s courses, which in turn changes their magnetic fields, which changes their paths, and so on and so on until you have absolutely no idea what the hell is happening.
Actually, there are some people who do have some idea of what’s going on. They don’t know what the hell is going on — they don’t even know what the purgatory is going on. They don’t even know what the bonfire is going on. But they do have a pretty good idea of what the match flame is going on. If you’d like to learn more about how magnetohydrodynamics works, just peruse this little slide show from Harvard: https://lweb.cfa.harvard.edu/~namurphy/Presentations/Introduction_to_MHD.pdf {
Evil snigger} 👹
Magnetic fields dominate the behavior of the visible surface of the sun.
Solar prominences are streams of plasma moving along lines of the magnetic field in that area.
Sunspots are regions in which the magnetic field lines dive straight down into the sun.
Most of the sun’s surface is covered with these granules, which are convective cells not driven primarily by magnetic forces. The average granule persists for only about eight minutes.
Then there are solar flares, eruptions of intense radiation.
All of this intense activity is attributable to the constantly changing magnetic fields in the sun. The sun’s complex system of magnetic fields is always in flux, changing in ways that are difficult to predict. I sometimes wonder if perhaps this activity reflects behavior of a living system deeper down. I rather doubt it, but it is certainly an interesting question to speculate about. Do you think that they might be waving at us with prominences? 😛
Whatever the dynamics of solar magnetic fields, nobody can deny that there is an immense amount of complex activity taking place inside the sun. If there are living systems inside the sun, they are utterly different in character from anything we know.
Other potential sites for life
If we consider life in terms of the two fundamental issues (source of negentropy and availability of a complex physical system), one possibility that scientists have speculated about arises from otherworldly systems similar to the hydrothermal vents in earth’s oceans. At least half a dozen of the moons of Jupiter, Saturn, and Uranus are believed to host subsurface bodies of water, and there’s a good chance that hydrothermal vents exist in these bodies of water.
I’m not optimistic that these sites host life. The amount of negentropy they provide is pretty low, so it would take a long, long time for a chemical system to assemble just the right components to trigger a living system.
Some scientists have speculated that hydrothermal vents were the nurseries for the first life on earth. They reason that the numerous indentations and open spaces in the chimneys around hydrothermal vents would provide an ideal fixed location for molecules to congregate and interact in the presence of chemical negentropy.
My reservation about this idea arises from the fact that the metabolic biochemical cycles necessary to harvest the chemical negentropy would have nothing in common with the metabolic biochemical cycles required for photosynthesis. There’s no apparent path by which living systems around hydrothermal vents could migrate to the surface and begin harvesting solar negentropy. The reverse course, in which creatures originating from photosynthetic sources could migrate to hydrothermal vents and adapt to harvest that source of negentropy is, on the other hand, entirely consistent with our knowledge of the life around hydrothermal vents. We know that the creatures that harvest the chemical negentropy of hydrothermal vents share the same basic DNA structures that every other living creature on earth uses.
Nevertheless, it is conceivable that simple living creatures could evolve around hydrothermal vents in other bodies of water in the solar system. Given the skimpy supply of negentropy available, I would expect their development to have taken far longer than it took on earth, and I very much doubt that we’ll ever find anything more than simple single-celled creatures.
Gas giants (Jupiter and Saturn)
These two planets have a lot of internal activity, which suggests that there might be some useful negentropy available. Jupiter emits a lot of radio energy, and its atmosphere is clearly quite energetic. There might be some atmospheric process that concentrates negentropy from lower in the atmosphere. However, it is difficult to imagine any physical mechanism that would support the kind of complex chemistry exploited by terrestrial life. I have no doubt that individual molecules of amino acids are forming all the time inside the atmospheres of these planets, but the odds of them encountering each other and engaging in chemical reactions seem remote. That’s just a wild guess on my part. If somebody wants to grind through the calculations to generate probabilities over billions of years, I’d be interested in seeing the results, but I suspect that such an effort would make Copernicus’ calculations in De Revolutionibus look like back-of-the-envelope scribbles.
Mercury, Venus, Earth’s moon, and Mars
Forget it.
At last! The conclusion!
This essay addresses only the simple yes-no question of the possibility of life developing in various locations. It does not address the matter of intelligent life. I agree with those scholars who suspect that the development of intelligent life on earth was something of a fluke. But that’s another story.