Ernst Mach and the Scientific Conception of the World

Abstract

1. A normal person who enjoys the use of his five senses and goes about his usual occupations “sees” that the surface of the earth spread out before his eyes is an endless plane interrupted only occasionally by elevations and depressions.¹ He “feels” that the earth is firmly at rest and “knows” that the sun rises in the celestial vault in the morning and sets at its base in the evening. A distant memory from his school days, slightly unreal and never properly understood, tells him that all this is mere deception. The earth is a sphere, and if you dig down under your feet and go on digging in a straight line, you will eventually come upon the feet of another person who carries his head upside down without having the slightest inkling that there is something odd about his position. Moreover, the earth is not at rest, but turns ceaselessly about its axis, and so rapidly that, as the earth rotates, we travel nearly thirty kilometres a minute, along with everything around us: houses, cities, rivers, and forests. And as if this were not enough, the terrestrial sphere itself sweeps through the universe at sixty times that velocity. Only the moon - oh yes, the moon - in this case everything is different: it really circles around the earth, and what is true of it is mere illusion in the case of the sun - but oh, how difficult it is not to be taken in by that illusion!