Sleepwalkers: Chapters 3 &4

The third chapter of Sleepwalkers for me showed that progress was being made. In the first section, it talks about how "Herodotus mentions a rumour that there exist people far up in the north who sleep six months of the year - which shows that some of the implications of the earth's roundness (such as the polar night) had already been grasped." This showed that people were starting to think of Earth as a floating sphere, which is a step in the right direction. Although Herodotus wasn't totally correct, its the thought that counts. Another good step was the "half-way house" of Herakleides, merging the geocentric and heliocentric views. It is not known whether Herakleides made the full step to the heliocentric idea, but Aristarchus was soon to follow and he did. Finally, the heliocentric model had made its way to the minds of people. Finally, there will be opposition to the geocentric model. However, this all suddenly ended after Aristarchus. "But here the development comes to an abrupt end. Aristarchus had no disciples and found no followers. For nearly two millennia the heliocentric system was forgotten - or, shall one say, repressed from consciousness?" Its amazing to think that an idea, correct (by our knowledge today), was forgotten for such a long time. The reasons behind this I doubt we will ever know.

Where Chapter 3 was more about how science was advancing in the right direction, chapter 4 is quite the opposite. In the opening lines, it mentions how "natural science begins to fall in disrepute and decay." This is where Plato and Aristotle started to rise. It seems to me that they were philosophers/theologians and astronomer as an afterthought. "Plato's contribution to astronomy - which insofar as concrete advances are concerned, is nil; for he understood little of astronomy, and was evidently bored by it. The few passages where he feels moved to broach the subject are so muddled, ambiguous, or self-contradictory, that all scholarly efforts have failed to explain their meaning." What he did develop in astronomy however, had a long lasting effect. He said that "the shape of the world must be a perfect sphere, and that all motion must be in perfect circles at uniform speed." He said that this must be true, and so it was then passed on to mathematicians to prove his idea, which "kept them busy for the next two thousand years." The failure of nerve is all about science's downfall, just when it was looking in the right direction.

The Greeks in no way convinced me that knowledge increases linear. At every point, science is not advancing at a constant rate. At some points there is a little spike with new findings, and at other points there are lulls, when nothing is found. To say that knowledge is always increasing linearly just doesn't make sense to me. It is also possible for knowledge to lower itself. "The Ionians had prised the world-oyster open, the Pythagoreans had set the earth-ball adrift in it, the Atomists dissolved its boundaries in the infinite. Aristotle closed the lid again with a bang, shoved the earth back into the world's centre, and deprived it of motion." Obviously, knowledge didn't increase at that point, but either slowed, or actually decreased. Also, it seems to me impossible to measure knowledge, so knowing how it grows would be impossible.