Toasting the testicles, or why thermodynamics rules

Electrical engineers Avik Gosh and Mircea Stan at the University of Virginia are looking to use nanotechnology to circumvent the second law of thermodynamics, which states that heat moves from a hotter to a colder body with which it is in contact until a state of thermal equilibrium is reached. The researchers’ aim is to construct powerful laptop computers that can actually be perched on male users’ laps without burning their most sensitive anatomical features.

The only conceivable around around the second law is via a thought experiment devised by the 19th century Scottish physicist James Clerk Maxwell. The conundrum known as “Maxwell’s Demon” theorises that the energy flow from hot to cold could be disrupted if the degree of natural disorder, or entropy, were reduced. In the natural world, entropy tends to increase, which explains why your tea gets cold, bodies age and dead organisms decay.

Gosh and Stan point out that nature has examples of systems that exist outside thermal equilibrium, including the chlorophyll molecules that power photosynthesis in plants. There are countless examples of non-equilibrium systems in the natural world. Life itself is a non-equilibrium phenomenon, but that doesn’t mean we can buck the laws of physics. We are all bound to the arrow of time, and so too are the machines we build.

Photosynthesis is a far from efficient mechanism. The process that turns photon energy into chemical energy in plant cells has an overall efficiency of no more than 6%, which is less than that of your average rooftop solar panel. The real beauty of photosynthesis is that nature has evolved a process which does the job using the limited resources available in the immediate environment. Photosynthesis provides inspiration to engineers, but they can and do improve on nature.

As for the fundamental physics, the field of science known as non-equilibrium thermodynamics, which takes in chaos, self-organisation and complex systems, is now well-developed. I expect that Gosh and Stan’s work will be subject to the most intense scrutiny from physicists who know a thing or two about thermodynamics.

Gosh and Stan may, along with others active in this field, succeed in engineering devices that drive a chemical system out of thermal equilibrium. But these will not violate the second law of thermodynamics as they would require an energy input from outside the system.

As an undergraduate student in the early 1990s I was taught that the four laws of thermodynamics were the most fundamental of all the laws of physics. So much can be derived from the principles that govern the working of heat engines, including the communication of information and the most exotic astrophysical phenomena.