Bringing this back more on topic (but still not exactly about "classic" computing): 2011 Isaac Asimov Memorial Debate on The Theory of Everything http://www.youtube.com/watch?v=lYeN66CSQhg That is a fantastically interesting symposium to watch in its entirety, but these parts relate to reality as a computer simulation: Dr. Jim Gates at: 0:09:20 Who he is 1:00:21 What he's found 1:34:15 More specifics about what he's found (binary error correction codes in string theory equations) In the Science Channel show Through the Wormhole, another scientist found that certain characteristics of quantum mechanics can be explained by reality being a computer simulation. He noted that within the next fifty years, the computational power of the human brain will be available in a laptop that consumes the same amount of power or less and that this rate of growth in computational power far exceeds evolutionary increases in the human brain size/computational power being limited currently by the size of the birth canal. He extrapolates that process over billions of years to posit a higher intelligence programming a mega-computer to create our reality. Wild stuff to think about. In another Science Channel show on the nature of reality, I believe it was stated that a room-sized quantum computer may have the power of a conventional computer the size of the universe. As a result of this and the limitations of growth in biological computational power through evolutionary means (although biological intelligence created in vitro may be a means around this once we actually understand the nature biological intelligence), the most likely form of an advanced technological civilization would be a computer with AI. So, any ET civilization older than ours that we'd contact would most likely be AI. Dr. Gates stated in his introduction that Asimov's stories had inspired him to become a scientist. Here's one of them that follows the above conjectures, a story which blew my mind when I read it as a youngster: The Last Question by Isaac Asimov http://www.multivax.com/last_question.html