Welcome to Beweisbar. This blog intends to address popular issues in science. To be completely honest, I write for selfish purposes.I take this blog as my motivation to learn because to be able to write something, I read articles, watch documentaries every week. I hope you enjoy reading the articles. For questions & comments, please reach me at mehmetkurtt@gmail.com.

Thursday, April 14, 2011

Boltzmann & Evolution: An admirer of Darwin

On  May 29, 1886, Boltzmann gave what is now regarded as a very popular lecture at the ‘Festive Session’ of  the Imperial Academy of Sciences in Vienna. When he was asked about his opinions about the new century, he replied as follows:

". . . If you ask me about my innermost conviction whether our century will be called the century of iron or the century of steam or electricity, I answer without hesitation: It will be called the century of the mechanical view of nature, the century of Darwin. . . ."   

Boltzmann was right. Unarguably, Darwin has become one of the key scientists of the century, radically changing our views about the nature, and the meaning of existence and human life.

Boltzmann's views on evolution

Ludwig Boltzmann (1844–1906) was the first scientist who tried to reduce the biological theory of evolution to the thermodynamics and chemistry of the 19th century. For scientists at the end of the last century,  a great challange was that the  second law of thermodynamics seemed to forecast the final disorder, death, and decay of nature, while  on the other hand, Darwin's theory of evolution indicated developing living systems of order with increasing complexity. How was the increase of complexity among living things possible in a sea of disorder and thermal equilibrium?

To understand views of Boltzmann on biology and evolution better, let's go back to his lecture in Vienna and quote him again:

"… The struggle for existence of the living beings is not a fight for basic materials—these materials are available in air, water and soil in sufficient quantities for all organisms– nor for energy, which is plentiful in the form if heat, unfortunately untransformably, in every body. Rather it is a struggle for entropy that becomes available through the flow of energy from the hot Sun to the cold Earth. To make the fullest use of this energy, the plants spread out the immeasurable areas of their leaves and harness the Sun’s energy by a process that is still unexplored, before it sinks down to the temperature level of the Earth, to drive chemical syntheses of which one has no inkling as yet in our laboratories. The products of this chemical kitchen are the object of the struggle ion the animal world. . . ."

Going back to the question about the complexity of life, Boltzmann suggested some explanations which already remind us of modern biochemical concepts of molecular autocatalysis and metabolism. The origin of first primitive living beings like cells was reduced to a selection of molecular building blocks which Boltzmann imagined as a process like Brownian motion. Plants as cellular aggregates are complex systems of order. Thus, in the sense of the second law of thermodynamics, Boltzmann suggests, they are improbable structures which must fight against the spontaneous tendency of increasing entropy in their body with sunlight. According to him, photosynthesis, as he also implied above in his quote, is merely an attempt to compansate the spontaneous increase of entropy in the plants, which makes use of the Earth's energy with relatively low entropy coming directly from the Sun.

Boltzmann on the evolution of nervous systems and brain

 The next step for Boltzmann was extending his views to the evolution of the nervous system and the emergence of memory and consciousness. He claimed that the sensitivity of the earlier primitive organisms to outer impressions led to the development of special nerves and organs of seeing, hearing etc. He believed that  the human brain has been developed with the same perfection as the giraffe's neck or the stork's bill.

Boltzmann on socio-cultural developments

Evolution of morality? Boltzmann believed so.
It may seem quite exaggerated, but Boltzmann even did not hesitate to extend his views about evolution to sociology.  He tried to justify human categories of  space, time and casuality as tools developed by the brain for the survival of the race. He saw "morality" as a "constantly evolving"  weapon for the struggle of life. Later in his life, his "Darwinism" has reached to an incredible point that in 1905, he gave a lecture called  "Explanation of the entropy law and love by the principle of the probability calculus". Well, anyways...

Boltzmann: More Darwinist than anyone else in the history

If you are interested in finding out more about how Darwin effected Boltzmann's views and studies, you can also take a look at his other works, especially "Boltzmann Brain", with which he is trying to explain why the observed entropy is so low.

At the beginning of the 20th century, life still could not be explained by physical and chemical foundations. Earlier on, classical mechanics always considered deterministic and time-reversible patterns in the nature. (A frictionless ball, when you push it, would move forever). But life wasn't working that way. Humans are born, grow and die.-Why? Maybe Boltzmann's statistical interpratations about Darwinian evolution were not enough to explain the origin of life. However, he clearly made his point when he commited suicide in 1909 in Duino,Italy, a person who sees death as a senseless biological and cultural event.

If you are interested to read more about this subject, see:

"Thinking in Complexity", Klaus Mainzer.
"Boltzmann and evolution: Some basic questions of biology seen with atomic glasses",Peter Schuster
"Boltzmann,evolution,atomism,statistics",Peter Schuster
"Dangerous Knowledge", BBC Documentary

Next week: Parallel Universes

No comments:

Post a Comment