East is digital, West is analog
Most people have a basic understanding of the difference between analog and digital. But the cause and origin of the distinction are rarely discussed. Is nature analog or digital, continuous or discrete? Does the brain operate on analog or digital signals? The issue is important in various disciplines, ranging from philosophy to artificial intelligence. It even appears to have a cultural dimension. Approach the distinction from a philosophical and esthetic perspective and we may conclude that the West is analog and the East (more specifically East Asia) is digital.
The analog-digital dichotomy was first discussed during the legendary Macy Conferences on Cybernetics held between 1946 and 1953. The conference brought together many of the leading thinkers of the era, including the people who set the digital revolution in motion. The analog-digital debate was the most contentious issue at the conferences. The discussions centered on the nature of the human brain and why it was important to computing.
Ralph Waldo Gerard, a neurophysiologist and behavioral scientist, claimed that the brain's operations are "much more analog than digital." He called into question the digital logic-based model developed in 1943 by neuroscientist Warren S McCulloch and logician Walter Pitts. They tried to explain how the brain could produce highly complex patterns by using many basic cells (neurons) that are connected.
After a contentious debate, famed social scientist George Bateson called for clarification of the distinction between analog and digital to remove remove ambiguities from the debate. Nobody came up with a satisfying explanation and the issue was shelved as "old business unresolved." In the following years, the digital approach to computing won the day, but for practical rather than philosophical reasons. Analog computers rely on the continuous variation of voltage, while digital computers deal only with discrete, unambiguous current - either on or off. Digital systems proved to be not only more stable, they were also easier to program.
Seventy years after the Macy Conferences, digital technology is ubiquitous, but the analog-digital dichotomy still causes confusion. The digital revolution led to the popular assumption that digital has replaced analog. We speak of "digital music," but there is no such thing as digital music. There is only digitally stored music. Sound is an analog wave. When we digitize audio, we "sample" the analog sound wave 44,100 times a second. We give each sample a binary number and write the resulting binary strings to a storage medium. For playback, we use a digital-analog converter to reconstitute the wave in order to make it audible. Our ear is an analog organ that only responds to waves.
Artificial intelligence is part of the reason for a renewed interest in the analog-digital dichotomy. Mathematician Freeman Dyson addressed the issue in his 2001 lecture "Is Life Analog or Digital?" Dyson stressed the difficulty of understanding brain functions like memory. He wrote:
"It seems likely that memories are recorded in variations of the strengths of synapses connecting the billions of neurons in the brain with one another. But we do not know how the strengths of synapses are varied. It could well turn out that the processing of information in our brains is partly digital and partly analog. If we are partly analog, the downloading of human consciousness into a digital computer may involve a certain loss of our finer feelings and qualities."
The latter point may very well be an elegant understatement. In biology and other sophisticated processes, let alone the human brain, loss of information, no matter how small, is decisive. Professor Dyson points at a third possibility: The processing of information in our brains is done with quantum processes, and the brain is the biological equivalent of a quantum computer. He adds this is merely speculation, noting that we have no evidence that anything resembling a quantum computer exists in our brains. "Whether a universal quantum computer can efficiently simulate a physical system is an unresolved problem in physics."
Quantum computing is said to hold the promise of virtually limitless computing power that will enable us to emulate the behavior of cell chemistry in minutes. Quantum computing uses quantum analog wave functions and is therefore analog, just like chemical and biological processes. Given sufficient computational speed, we could create an electric liver or immune system and test drugs in minutes rather than years, and do so without killing laboratory animals. But quantum computing faces major challenges, among them exacting demands of stability and temperature.