" However, the answer can be inferred from the WMAP data, by measuring the sizes of the temperature fluctuations—the hot and cold (light and dark) splotches in Figure 3 ([>]). Before WMAP was launched, theorists had already worked out how big the physical sizes of the strongest fluctuations should be. Converting that into apparent angular size in the sky depends on the geometry of space: if the universe is positively curved, it would make the angles appear larger, while negative curvature would make them smaller. If the universe is geometrically flat (that is, has Euclidean geometry), the angular size of the strongest hot and cold fluctuations should be about 1° across. The results that flowed back from the satellite were definitive.14 The fluctuations were very close to 1° in size, a result confirmed by ground-based and balloon-based experiments. Cosmologists then declared that to within observational accuracy of about 2 percent, space is flat.15 "
― Paul C.W. Davies , The Goldilocks Enigma: Why is the Universe Just Right for Life?
![Paul C.W. Davies quote : However, the answer can be inferred from the WMAP data, by measuring the sizes of the temperature fluctuations—the hot and cold (light and dark) splotches in Figure 3 ([>]). Before WMAP was launched, theorists had already worked out how big the physical sizes of the strongest fluctuations should be. Converting that into apparent angular size in the sky depends on the geometry of space: if the universe is positively curved, it would make the angles appear larger, while negative curvature would make them smaller. If the universe is geometrically flat (that is, has Euclidean geometry), the angular size of the strongest hot and cold fluctuations should be about 1° across. The results that flowed back from the satellite were definitive.14 The fluctuations were very close to 1° in size, a result confirmed by ground-based and balloon-based experiments. Cosmologists then declared that to within observational accuracy of about 2 percent, space is flat.15](/image/2505993.jpg)