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The Thermosynthesis Home Page

The most recent developments can be found in my latest abstracts and submitted papers, the latter can often be found on

ongoing construction

by Anthonie Muller

under construction
April 2009
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simplex veri sigillum
from negative entropy -- by evolution -- to intelligence

What is thermosynthesis ?
The basic tenet of the thermosynthesis (TS) theory is that
thermal cycling yielded the scaffolding for the origin and evolution of life.

The content of a convection cell is continuously thermally cycled. In the shown ice-covered volcanic hot spring convection is particularly intense because of the large temperature gradient.

  • Many organisms or cell components are thermally cycled: Archaebacteria in convecting hot springs, organisms vertically migrating through thermoclines in natural waters, chloroplasts and mitochondria in the protoplasm stream in leaf cells.

  • Many physiological phenomena invoke thermal - or light - cycling: cell division, germination, flowering, budding, heat shock. This thermoperiodism and photoperiodism may be a relic from thermosynthesis during early evolution.

  • As it yields a simple energy source, thermosynthesis (TS) considerably simplifies the problem of the origin of life. The emergence of today's biological energy conversion machinery is easily modelled.

  • Biological regulation mechanisms by protein phosphorylation or by Ca2+ may be ways to mimic thermal cycling, acquired at the transition from living at a fluctuating to living at a constant temperature.
On biological heat engines
In thermosynthesis an organism functions as a heat engine. This analogy between dead machines such as the steam engine and living organisms may seem farfetched. A comparison may help:
In the steam engine water is thermally cycled: liquid water is heated in a boiler, where it turns into steam - a phase transition. The expanding steam performs external work. In the condensor the steam turns again into liquid water, the reverse phase transition.
In the two thermosynthesis mechanisms a protein or a membrane is similarly thermally cycled, and undergoes a phase transition to an unfolded or more fluid state. The external work consists of the synthesized ATP.

In a steam engine the product, mechanical work, is obtained outside the system, while in thermosynthesis the product is formed inside. Here ADP and phosphate are 'pushed together' to form the ATP that is released. The difference in topology, 'inside' and 'outside', is however not important.

Extraterrestrial life
Thermosynthesis may play a role in many extraterrestrial environments. Thermal cycling of water can occur in many places, in the Solar System on Mars, Europa, and comets. The ocean under the surface ice on the Jovian moon Europa is a particularly interesting potential niche for TS.

Terrestrial life
Several biology and biochemistry text books state that organisms are not heat engines. In contrast to engines such as the steam engine, organisms would be unable to use heat as an energy source. The recognised two classes of biological energy sources are (1) light, used by plants during photosynthesis, and (2) food, chemicals used by animals during (2a) respiration, which requires oxygen or another oxidator or (2b) fermentation, which does not require an oxidator; an example is the fermentation of sugar by yeast.

For power production, TS is expected to have lost the competition to photosynthesis or chemosynthesis a long time ago in those places where light and food were available. Where these were not, and where thermal cycling is possible, TS may however still occur. TS-like phenomena may also play a role in the many physiological phenomena which involve thermal cycling but do not involve power production.

The novelty of thermosynthesis
TS is interdisciplinary, combining concepts from physics, especially thermodynamics, physical chemistry, biophysics, and biochemistry. The theory is based on the chemiosmotic mechanism which governs the synthesis of most energy-carrying ATP in almost all organisms.

The notion that organisms could use heat as an energy source, and that for instance a muscle could function as a heat engine, was extensively discussed in the late nineteenth century. The high energetic efficiency of muscle and the difficulty of envisaging the required local thermal gradients were convincing counterarguments against such involvement. These counterarguments do however not apply to energy conversions outside muscle, which could be based on unfolding of a protein or a thermotropic phase transition in a biomembrane, nor to an organism that is thermally cycled or contains an internal thermal gradient.

The chemiosmotic mechanism
In the 60s Williams and Mitchell proposed the chemiosmotic mechanism for the synthesis of ATP, the energy source for almost all physiological processes. The mechanism applies to both respiration and photosynthesis. We consider photosynthesis:

Bacteria, chloroplasts and mitochondria contain a closed membrane. In chloroplasts and the photosynthetic bacteria this membrane contains photosynthetic reaction centers that upon light absorption pump protons across the membrane. This membrane thus becomes charged and stores electrical energy just as a capacitor.

The protons fall back through the ATPsynthase enzyme, which transduces their electric energy into the chemical energy of ATP. Note the complexity because of the numerous steps and interwoven, coupled cycles.

The chemiosmotic machinery of bacterial photosynthesis (fast animation). The components are arranged according to the partial steps of the transduction process. The free energy (red) is present as light, exciton, electron, quinol, proton gradient, conformational energy, and finally ATP: (the Q-cycle is not shown)

The chemiosmotic machinery of bacterial photosynthesis in slow animation:

The components of the chemiosmotic machinery arranged according to the sequence of acquisition proposed by the TS theory:

Some links to data on the web on the chemiosmotic mechanism:

Antony Croft at the University of Illinois at Urbana,
on bioenergetics
on ATP Synthase

Joyce Diwan at Rensselaer University

Wang and Oster at the University of California, Berkeley

Rod Capaldi at the University of Oregon

TS is a physical theory for the stepwise emergence during evolution of the contemporary biological energy conversion machinery. It also gives a solution in terms of basic physics for the problem of the self-organization of the origin of life. It permits a solution to the problem of the emergence of the genetic machinery.

Since information processing is only possible in the presence of an energy source, the energy source must come first.

TS may still occur in the world around us. Many industrial installations, and even our homes, contain niches favorable for thermosynthesizers. On a larger scale, the Solar System, and even the entire Universe, may be teeming with thermosynthesizers, but the isothermal methods currently used by microbiologists to isolate and breed microorganisms would not be able to detect them!

Thermosynthesis is my own personal theory that theory is certainly not generally accepted, or even known. New concepts have to start with a 'minority of one,' and a 'social proof' can take a while. And the idea may of course also be wrong or irrelevant. I have however published several papers in peer refereed scientific journals.

The general knowledge of thermodynamics is very limited. A few years ago I saw thermodynamics in Physics Today compared to a dead language such as Latin. Once after I had given a seminar a life-sciences post-doc told me sincerely, and slightly patronizingly, that my ideas were based on a misunderstanding of the laws of thermodynamics. The Second Law would state that heat could not be converted into work. I mentioned the steam engine as a counterexample. He had not thought about that, but the steam engine was just a paradox to him, and there probably was a simple explanation for that. He remained convinced about the correctness of his interpretation of the Second Law.

Any contemporary college physics textbook explains the basic principles of thermodynamics. The best treatments are given in engineering textbooks, in which a life scientist will however seldom browse. Biologists tend to have an aversion of machines. Physical chemistry textbooks treat thermodynamics well too, although the subject faces much competition there; the older the textbook, the better the treatment.
In my student days thermodynamics was rather impopular with my fellow chemistry students, but if one has grasped its necessity and logic, the ugly duckling is a real beauty. Obviously I hope that thermosynthesis will similarly turn into a pretty swan. Enjoy your flight with thermosynthesis!

The following web pages treat TS in detail.
  1. Introduction
  2. Protein-associated thermosynthesis: PTS
  3. The Origin of Life (under revision)
  4. Membrane-associated thermosynthesis: MTS
  5. Photosystem 0: PS0
  6. Terrestrial thermosynthesis niches
  7. Extraterrestrial thermosynthesis niches
  8. Conclusion

"Photosystem 0 - a postulated primitive photosystem that generates ATP in fluctuating light"

Unpublished paper (1995) on the evolution of photosynthesis in the thermosynthesis theory: Acrobat file (PDF) (86 pages)

"Life on Mars?"

Reaction (1996) to a letter in Nature that stated that the chance of backward contamination by life on Mars is small: Acrobat file (PDF) (1 page)

"Photosystem 0, a proposed ancestral photosystem without reducing power that synthesized ATP during light-dark cycling"

In the Physics Preprints archive: a shorter version (2005) of the previous 1995 paper on Photosystem 0: Acrobat file (PDF) (9 pages, 5 figures)

"Thermosynthesis as energy source of the RNA World: a new model for the bioenergetics of the origin of life"

Preprint (2005) in the Physics Preprints archive of a submitted paper: Acrobat file (PDF) (11 pages, 6 figures) Paper has been accepted by BioSystems.

"Sorption heat engines "

Paper published by the author with Dirk Schulze-Makuch Preprint (2005) in the Physics Preprints archive of a submitted paper: Acrobat file (PDF) (10 pages, 7 figures)

"Thermal energy and the origin of life"

Paper published by the author with Dirk Schulze-Makuch In Press (2006)

Poster presented at the ISSOL conference on the origin of life in San Diego, July 1999; this poster gives a concise introduction to TS: poster (HTML) poster (PDF)

Abstract for the First Astrobiology Science conference at NASA Ames Research Center, April 2000: abstract
Poster published by the author with Michael Kaufmann and Claudia Klinger at the 8th International Conference of Bioastronomy in Reykjavik, July 2004: poster (HTML)

Abstract published by the author with Michael Kaufmann at the 1st Conference on Advanced Nanotechnology in Washington DC, October 2004: abstract

"THERMOSYNTHESIS: A Binary, Periodic, Thermo-Chemical Model for Energy Capture, Replication, Error Correction, and Biochemical Infection"

Document independently developed by Peter Huber (2004): website (HTML) Acrobat file (PDF)

"On the Free Energy that drove primordial anabolism"

Document independently developed by Michael Kaufmann (2009): Acrobat file (PDF)
International Journal of Molecular Science vol 10, 1835-1871

a b c d e f g h i j k l m n o p q r s t u v w x y z

Copyright 1999-2009 Anthonie W.J. Muller

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