This edition: Biophysics
Following the example set in the previous unit, we now attempt to bring principles of physics to bear on the most complex systems of all: biological systems. Is it possible to describe living systems, or even small pieces of living systems, with the same concepts developed elsewhere in our ramble through physics? We begin with a discussion of whether physics can tell us if something is, in fact, alive. In the reductionist spirit, we then consider the physical principles that govern the constituent molecules of biological systems—and their emergent properties. From DNA and proteins, we move on to evolution and how it is physically possible for a species to genetically adapt to its environment quickly enough to survive. Finally, we seek to understand how the conscious mind can emerge from a network of communicating cells.