Hubble trouble, and make it double: Disagreement over one of the universe’s most important constants
In the beginning, all that would become the universe was concentrated into an extremely small, dense, high-energy speck of space. In the fractions of seconds that followed, this singularity exploded: one hundred decillionths (10–35) of a second after, it expanded to nearly the size of a soccer ball; after one nonillionth (10–30) of a second, […]