Slashdot Mirror
A Thermodynamics Theory of the Origins of Life
New submitter SpankiMonki writes "Natalie Wolchover at Quanta Magazine has written an article about how Jeremy England, a MIT professor, may have found a theory of the origin of life grounded in physics. In a paper published last August by The Journal of Chemical Physics, England describes his theory, the 'Statistical physics of self-replication.' Wolchover writes, 'England['s]...formula...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.' England says his ideas pose no threat to Darwinian evolution: 'On the contrary, I am just saying that from the perspective of the physics, you might call Darwinian evolution a special case of a more general phenomenon.'"
Can anyone with more info on this tell me how this earlier paper is different - arxiv.org/abs/0907.0042
Mercury has no ocean or atmosphere to act as a heat bath, so there goes one counter-example. And while Venus has a thick atmosphere, it doesn't necessarily have the right chemicals for life to arise, so there goes your second counter-example.
No colour or religion ever stopped the bullet from a gun
Depends on the definition of "life" at that point. Mercury should have lots of crystallization effects which release energy during formation... But the excess heat would also remelt... And crystals do "grow"... And they can even reproduce (by fission when the crystal fractures...)
In the case of Venus - insufficient information for a meaningful answer...
I think this is specifically water based, or at least where things can be water like.
With water you get a scum boundary. Thermically there will be pressure to move the heat through the scum boundary. Which will generally be less thermally conductive. This will promote chemical processes that move the heat through the boundary.
The scum boundary becomes cell membranes and the chemical processes then become cellular mechnisims that seek their own energy input (feed on available chemically stored energy).
Even if there's some truth behind the theory in the article, I'd still expect there to be a range of conditions under which life would be possible. Venus is probably out of it. While it seems unlikely that there's life on Venus now, it's still possible that there was life on Venus earlier in its history when (and if) the conditions were less extreme. (Although I can't imagine that anybody would be able to get any evidence for it, if it did exist.)
And now science has come full circle and once again believes the sun is god.
Physicists sometimes have it easy. This kind of thing is akin that old joke about treating a cow like a sphere.
Look with the chemical origin of life, that it was governed by physics is not in debate.
What matters are the details, what came first; RNA world, life on a metallic surface, or some thing else?
I have this to toss at so-called astrobiologists who claim that life is spontaneous and easy.
If it is so easy why is there only one kind of life -- 20 amino acids, 4 DNA/RNA bases? To a bio organic chemist the "selection" of this chemical code is arbitrary. Why do we not live in an ecosystem with a shadow "alternative" biosphere? After all life existed for 3 billion years on this planet before even becoming multi-cellular. Plenty of time for chemical weirdos to develop a four base genetic code templating for D chirality beta amino acid chains with side chains made of silicon.
Step off physicists, this field belongs to chemists.
Possibly because the 'heat bath' description is somewhat simplistic. The earth has environments where organisms, or more simply clumps of molecules can lose energy locally. You have a dark surface that absorbs sunlight more effectively than the puddle of water you reside in and you lose energy to that puddle.
The environments of Mercury and Venus lack temperature differentials that would drive such a process.
Have gnu, will travel.
Mercury has no ocean or atmosphere to act as a heat bath, so there goes one counter-example. And while Venus has a thick atmosphere, it doesn't necessarily have the right chemicals for life to arise, so there goes your second counter-example.
From TFS:
Where do you see the word "chemicals?"
An enigma, wrapped in a riddle, shrouded in bacon and cheese
his light? But the Cosmic Mother was female, everybody knows that!
Those people who think they know everything are a great annoyance to those of us who do. (Isaac Asimov)
Whenever I hear about a physicist who explains a problem from outside his area of expertise with a few simple equations, I think about this Saturday Morning Breakfast Cereal cartoon: http://www.smbc-comics.com/com...
In the Journal of Chemical Physics, England describes YOU!
"Place me in the company of those who seek Truth, but deliver me from those who believe to have found it."
The theory doesn't insist on life -- it simply further develops a principle that actually goes back IIRC to work by Prigogene on self-organization in open system (although I'm too lazy to look it up to be certain) and that is observed in phenomena like the transition from conduction to turbulent convection. The interesting thing is extending it to the microscale and chemistry.
Also, what's wrong with the "and" operator here, as well? Given a temperature range and physical environment conducive of complex chemistry between free energy sources and free energy sinks, self-organization of the chemistry to optimize the generation of entropy, via a natural selection favoring those processes that are most efficient at transferring the energy from a rate limited source AND that possess a certain "stability" in the physical environment. Self-replicating processes might not always be the most efficient, even, but they might possess the stability needed, or not. Once you have the self-replication, though, you have a pathway to life. Urey-Miller isn't even contradictory of this -- the nucleation of the self-replicating processes itself likely requires random noise to generate the soup in which the requisite self-organizing chemistry can take place.
rgb
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
Clearly the original poster intended to signify a to-be-defined set of “usable” chemicals. It is clear to everybody versed in even rudimentary chemistry that a concentration of noble gasses would not give rise to life for the simple reason that though concentrated they do not react. Thus the expected reactivity of the chemicals under consideration becomes a key concern. The building blocks of life as we know it (carbon, oxygen, nitrogen, & cetera) is a pretty reactive bunch of stuff.
I expect professor English has already formalised this (fairly trivial) observation in his work. If that is not the case, it could no doubt be effortlessly included. I do not believe it to be a profound point. I especially resist the tendency Slashdot users often display of building straw-men absurd logical reductions.
"Place me in the company of those who seek Truth, but deliver me from those who believe to have found it."
The problem is how would you *detect* unfamiliar life? It's not like it gives off life-onium rays. You can detect particular chemicals you believe are produced by certain kinds of life, but that's a pretty narrow detection window. The best bet would probably be collecting samples and monitoring them for long periods under a powerful microscope looking for activity or complex organized structures, but even that would presume that the local life is active or organized in away we can see and understand. A simple crystalline life form for example might well appear like nothing more than a grain of sand on human timescales. Hell, aside from their propensity to arise spontaneously you could almost classify fire and crystals as life forms already - they "eat", they grow, they reproduce, fire even excretes, and crystals manage the organized self-replication with errors. If the errors were cumulative instead of structural they would be evolving already.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
>It is clear to everybody versed in even rudimentary chemistry that a concentration of noble gasses would not give rise to life
That depends entirely on the environment - at sufficient temperatures and pressures the noble gasses become quite active. In fact they might be some of the few elements still non-volatile enough to build a stable chemistry around.
Yeah, chemistry is weird - it's built directly upon quantum mechanics after all. And we're only beginning to understand how extremely biased our understanding is towards "chemistry that can occur at STP".
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Define life. Fire and crystals are extremely close by many definitions. Viruses are borderline, being clearly life by some and clearly non-life by others - they do not eat, excrete, respire, or even self-replicate by themselves, instead relying on subverting the self-replication capacity of other life to do so.
If you go by the increasingly popular definition of life as "capable of imperfect self-replication", which is necessary and sufficient for evolution to kick in, then crystals and fire are extremely primitive forms of life - fire's self-replication is too unstable for evolution to accumulate complex functionality, and crystals are generally far too stable and self-correcting. Both death-knells for productive evolution.
But hey, they perform abiogenesis at the drop of a hat, so who knows what might exist out in the cosmos. On Mercury or Venus for example the high temperatures might well make many crystals unstable enough that they become capable of evolution. A little alloy contamination here, a little structural reinforcement there, and suddenly the crystal can survive environmental fluctuations, but is no longer capable of perfect self-replication, and voila, evolution is off to the races.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Well, your right; most of the population will settle for nothing less than little green men with anal probes, flying saucers and prescient, liberal advice for our species (Venusians would be all about the greenhouse effect).
I for one, would be fascinated to find Venus teaming with wacky crystal structures that display just the right amount of entropic dissipation to give physicists hardons.
Unless someone can prove how intelligent life arises inevitably (and given Earth's long history without anything most of us would find intelligent) I suspect we'll never find anything worth communicating with, which I think is what I think most layman actually mean when they say "life."
"England says his ideas pose no threat to Darwinian evolution."
...
* Why would the article, or England for that matter, feel the need to explicitly state this?
[opinion] I feel like the scientific community has so rabid about avoiding anything resembling creationism that they have to reassure themselves when new ideas come up, even if the ideas are no threat to their core beliefs. [/opinion]
For more context, from the article:
England’s theory is meant to underlie, rather than replace, Darwin’s theory of evolution by natural selection, which provides a powerful description of life at the level of genes and populations. “I am certainly not saying that Darwinian ideas are wrong,” he explained. “On the contrary, I am just saying that from the perspective of the physics, you might call Darwinian evolution a special case of a more general phenomenon.”
I think what you are calling "rabid" is merely a defensive reaction to the dialogue from the camp that can't accept the reality of Darwinian theory.
There are plenty of examples of Darwinian unbelievers ;-) either misunderstanding or misrepresenting accepted or hypothesized scientific ideas in order to sway others. I recall a blurb (handed to me at the door of the house) that attempted to shoot down the scientific picture of "creation", and it quoted Stephen J. Gould directly disagreeing with the gradual evolution of species. Anyone somewhat familiar with the finer points of evolutionary theory will notice what was done there: it was probably a quote of Gould defending his qualifying theory of Punctuated Equilibrium, but taken out of context to apparently support creationism! (It also says a lot about the intended audience's level of informedness and critical thinking...)
As for the article, all we know is that in explaining his work to the reporter, he felt he had to say "I am certainly not saying that Darwinian ideas are wrong." Given the syndrome I referred to above, CYA responses like this are understandable. (BTW, I'm not implying the reporter asked something silly like "So does this contradict Darwinian theory"; more than likely she's well aware of this "syndrome" and doesn't want to further enable it.)
You must be those guys who label organic food with "contains no chemicals" and similar nonsense.
Don't be a jackass. OP said "Venus doesn't have the right chemicals," which completely ignores the premise of the paper - that, in the right conditions, individual atoms will come together in just-such-a-way to form the "right chemicals" for life.
Here's a hint: a "group of atoms" difinitively implies one or more chemicals.
No, it implies more than one atom. Kinda like how the phrase "set of tires" implies more than one tire, but not a whole car.
An enigma, wrapped in a riddle, shrouded in bacon and cheese
Yes, I assume you've read about the recent creation of NaCl3, NaCl7, Na3Cl2, Na2Cl, and Na3Cl at high pressures, compounds not possible in standard chemistry.
‘Impossible’ Sodium Chlorides Challenge Foundation of Chemistry
Hydrogen, Venus used to have tons of it bonded to oxygen in an ocean, the ocean boiled under a runaway greenhouse, radiation then split the water vapour blasting the hydrogen off the planet. The oxygen then found some carbon to bind with which is why it's called a "runaway" greenhouse. The fate awaits the Earth in roughly half a billion years.
As TFA said "life is a special case", ie: Life needs certain ingredients in a specific environment to be the most efficient way to dissipate energy, but life is not the only example of spontaneous self-organising matter (crystals are an obvious example). This guy's idea attempts to explain ALL spontaneous self-organization of matter as a natural consequence of the second law of thermodynamics. When you get down to the molecular scale the line between alive and not-alive is poorly defined, my personal opinion is that "life" is an arbitrary distinction between different types of chemistry, a word invented by humans to more easily comprehend and talk about the world around us. Interestingly the distinction between alive and not-alive is a modern way of seeing the world, the oldest tribal religions (polytheism) believed everything had a spirit (was alive), including rocks, clouds, and celestial bodies.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.