Flat Worlds: Today and in Antiquity

Didier De Fontaine

So, Euclid was right after all! Very recent results from two largely independent astrophysics groups have shown the geometry of the Universe to be practically "flat", meaning that the radius of curvature of space as a whole is extremely large with respect to the radius of the observable Universe. It is interesting to compare this finding with the pre-Hellenistic belief that the world was flat, at least on the scale of the observable universe of the times. In such early days, the religious implications of the flat geometry were straightforward: the assumed three-tired universe, Hell - Earth - Heaven, defined a unique "morality vector" pointing straight up. Later Greco-Roman introduction of curvature, with the attendant loss of a unique direction, must have played philosophical and religious havoc on the culture of the times. It remains to be seen whether the new concepts of accelerated universal expansion, flatness, dark matter, "quintessence," will be as disturbing to present culture and religion as were previous scientific revolutions.