Hearing heat motion.

Thoughts on Schrodinger's first lecture in What is Life?

Schrodinger begins his exploration into Life with the question of why our bodies are so big compared to an atom. He cites a common frustration among those of us that study the very small, which is that our human senses are insensitive to them. This, as we discussed in August, necessitates that our observations be indirect. He presents an argument as to why it must be this way by explaining the statistical thermodynamic principle that the ordered phenomena we observe (e.g. paramagnetism and diffusion) result from the averaged behavior of independent atoms. These atoms are influenced by thermal fluctuations (he calls them “heat motion”), each other, as well as the force being tested, such as a magnetic field. Therefore, when observed as an ensemble, particles in a magnetic field align with the field. However, if your level of sensitivity was on a single particle scale, the pattern would seem confusing and chaotic. Our senses are thus tuned to relay to our brains, averages. Thus, a paradox that he highlights is that in the process of achieving the level of complexity required to comprehend the concept of a single atom, a human being has lost the ability to sense a single atom.

The perpetuum mobile project thus, strives to restore to us, through the aid of machines, a level of sensitivity that only our most distant unicellular biological relatives still possess: the ability to “hear” heat motion.