I have just started George Dyson's most recent book, Analogia: The Emergence of Technology Beyond Programmable Control. His past works, like Turing's Cathedral and Darwin Among the Machines, were incredibly eye-opening for me. Criminally obscure figures like Nils Barricelli and Samuel Butler were brought to the forefront, people whose work both reflects and affects our digital present.
Here's a mind-blowing passage from the beginning of the book about how analog and digital computing relate to one another, especially from a biological perspective.
Nature uses digital coding, embodied in strings of DNA, for the storage, replication, modification, and error correction of instructions conveyed from one generation to the next, but relies on analog coding and analog computing, embodied in brains and nervous systems, for real-time intelligence and control. Coded sequences of nucleotides store the instructions to grow a brain, but the brain itself does not operate, like a digital computer, by storing and processing digital code.
In a digital computer, one thing happens at a time. In an analog computer, everything happens at once. Brains process three-dimensional maps continuously, instead of processing one-dimensional algorithms step by step. Information is pulse-frequency coded, embodied in the topology of what connects where, not digitally coded by precise sequences of logical events. “The nervous system of even a very simple animal contains computing paradigms that are orders of magnitude more effective than those found in systems built by humans,” argued Carver Mead, a pioneer of the digital microprocessor, urging a reinvention of analog processing in 1989. Technology will follow nature's lead in the evolution of true artificial intelligence and control.