 Different values of \(\lambda\) lead to different scenarios for the evolution of the universe. With \(\lambda = 0\), if the curvature of space is negative or null we end up with a constantly expanding universe; if the curvature of space is positive, a phase of expansion would be followed by a contraction leading to a “big crunch”. Other values of the cosmological constant are possible and if \(\lambda \lt 0\) a “big crunch” will occur no matter what the curvature of space is. By contrast, if \(\lambda \gt 0\), no “big crunch” will occur. New experimental evidence (coming from type 1A supernovae and fossil radiation) seems to indicate a positive mean density of matter and a value of \(\lambda \gt 0\). In this case the universe would be finite while still remaining in perpetual accelerated expansion.