I heard a scientist on the radio say today (without proof) that he thought that mankind would have made it to the Moon 200 years earlier if the Library of Alexandria had not burned down. Over the years, I've wondered why science & technology & math did not get further in the ancient world, so I'm curious if others have had similar ideas. Clearly the Roman Empire had a pretty decent standard of living -- it wasn't matched again in the Western world until the Victorian times -- probably due to the "Rats, Lice & History" rationale -- you don't get sick nearly as much when you have a decent sewer system. The population of Rome fell from a height of well over 1 million at the height of the Roman Empire to less than 30,000 in some parts of the Middle Ages -- the water, sewer and street systems had fallen into such disrepair that it could not support a big population. Clearly the Romans had good techology -- their weapons were excellent, their ships were excellent, etc. The Chinese of the same time period already had a very advanced system for sifting the population to find the best & brightest for their bureaucracy. The astronomers of China, Persia & certain parts of the Roman Empire were superb. Most of the geometry required for Kepler's Laws was known to some of the ancient mathematicians. What happened? Or what didn't happen? Was the printing press part of the answer? But the Chinese had printing. Was the human race set back by its failure to backup important files?