大数据不等于科学规律( 三 )_我们从天文学史获得的重要教训是

古希腊天文学家则用了两种不同的方法来理解同一组数据。第一种方法是构建几何模型，即将太阳、月亮、行星和恒星视为一个个抽象的发光点，分别固定在某个匀速旋转的天球上。

The ancient Greek astronomers used two distinct methods to understand the same data set. The ?rst was to make geometric models that treated the sun, moon, planets and stars as mathematical abstractions—shiny points carried upon uniformly rotating celestial spheres.

起初，希腊人的预测并不比巴比伦人强，事实上差很多。为了改进，他们假设光点在天球上不是固定的，还在沿着额外的圆周轨道运动，即本轮。公元2世纪时，这种模型体系在天文学家托勒密（Ptolemy）手中臻于完美。尽管在后人看来，托勒密的模型是冗杂笨拙的，但在当时，它确实提供了一种相对紧凑的框架体系来包容大量的天文数据，并且给出了有用的实际结果。

At ?rst, the Greeks' predictions were no better than those of the Babylonians—in fact, they were signi?cantly worse. But they patched things up by postulating additional movements of the spheres, called epicycles. These models, which were perfected by the 2nd-century astronomer Ptolemy, seem ugly in retrospect, but they did package the astronomical data in a relatively compact form, and they gave useful practical results.