Errors are feared in carbon dating
Friedmann in the Soviet Union, Willem de Sitter in the Netherlands, and Georges Lemaître in Belgium, based on Einstein’s general theory of relativity, showed that the expanding universe could be explained in terms of the evolution of space itself. Its departure from Euclidean space is measured by a “curvature” that depends on the density of matter.According to Einstein’s theory, space is described by the non-Euclidean geometry proposed in 1854 by the German mathematician G. The universe may be finite, though unbounded, like the surface of a sphere.
Hubble’s velocity–distance relation suggested that the universe of galactic nebulas is Calculations by Aleksandr A.
Some of them were close enough to have measurable parallaxes so that their distances and thus their intrinsic brightnesses could be determined.
She found a correlation between brightness and period of variation.
Using Leavitt’s period–brightness correlation, Hubble estimated its distance to be approximately 900,000 light-years.
Since this was much greater than the size of the Milky Way system, it appeared that the Andromeda Nebula must be another galaxy (island universe) outside of our own.
Some astronomers considered them to be “island universes”—huge stellar systems outside of and comparable to the Milky Way Galaxy, to which the solar system belongs.