Scientists made that point anew on Monday in a study that used observations of a ferocious class of black holes called quasars to demonstrate "time dilation" in the early universe, showing how time then passed only about a fifth as quickly as it does today.
The observations stretch back to about 12.3 billion years ago, when the universe was roughly a tenth its present age.
Quasars - among the brightest objects in the universe - were used as a "clock" in the study to measure time in the deep past.
Quasars are tremendously active supermassive black holes millions to billions of times more massive than our sun, usually residing at centers of galaxies.
The explosion of individual stars cannot be seen beyond a certain distance away, limiting their use in studying the early universe.
Persons:
Albert Einstein, Dr, Geraint Lewis, Lewis, today's, Will Dunham, Rosalba O'Brien
Organizations:
University of Sydney, Thomson
Locations:
Australia