US and UK scientists have proposed an alternative to the Big Bang theory of the universe:
The new ideas, reported in the journal Science, may explain why the expansion of the Universe is accelerating, the researchers say.
"At present the conventional view is that all of space, time, matter and energy began at a single point, which then expanded and cooled, leaving the Universe as it is today," said Professor Paul Steinhardt of Princeton University, New Jersey.
"However, this new theory suggests that there's a continuous cycle of universes, with each a repeat of the last, but not an exact replica.
"It can be thought of as a child of the previous universe."