Turing biographer Andrew Hodges writes in today’s issue of Science:
But more deeply, anything that brings together the fundamentals of logical and physical description is part of Turing’s legacy. He was most unusual in disregarding lines between mathematics, physics, biology, technology, and philosophy. In 1945, it was of immediate practical concern to him that physical media could be found to embody the 0-or-1 logical states needed for the practical construction of a computer. But his work always pointed to the more abstract problem of how those discrete states are embodied in the continuous world. The problem remains: Does computation with discrete symbols give a complete account of the physical world? If it does, how can we make this connection manifest? If it does not, where does computation fail, and what would this tell us about fundamental science?
Personally I find this the most interesting question in science. It’s what drew me to biology, and it is what drives my current research in gene regulation. The problem of gene regulation is a problem of computation, and what is remarkable is the fact that genetic information is stored digitally as a string of discrete, two-bit chemical units. It didn’t have to be that way, and people* didn’t think that way until Schrödinger’s speculations on aperiodic crystals and the discoveries of molecular biologists in the 50’s and 60’s.
*To be fair, geneticists were thinking digitally, beginning with Mendel, and continuing, after a hiatus, with the early 20th century pioneers. But these geneticists didn’t really didn’t care about the physical implementation of genetic information. Those who did think about it weren’t thinking in terms of digits.