08 Aug 07
Ultimately, speeding up intelligence is probably comparatively unimportant next to creating better intelligence; nonetheless the potential differences in speed are worth mentioning because they are so huge. Human neurons operate by sending electrochemical signals that propagate at a top speed of 150 meters per second along the fastest neurons. By comparison, the speed of light is 300,000,000 meters per second, two million times greater. Similarly, most human neurons can spike a maximum of 200 times per second; even this may overstate the information-processing capability of neurons, since most modern theories of neural information-processing call for information to be carried by the frequency of the spike train rather than individual signals. By comparison, speeds in modern computer chips are currently at around 2GHz – a ten millionfold difference – and still increasing exponentially. At the very least it should be physically possible to achieve a million-to-one speedup in thinking, at which rate a subjective year would pass in 31 physical seconds. At this rate the entire subjective timespan from Socrates in ancient Greece to modern-day humanity would pass in under twenty-two hours.— What is the Singularity? | The Singularity Institute for Artificial Intelligence