The universe is expanding faster than expected and scientists speculate the finding may be explained by a mysterious force called dark radiation. Key points
Universe is expanding 5 - 9 per cent faster than previously estimated
Expansion could be caused by weird things happening with dark energy or dark matter
Or a mysterious force known as dark radiation, a new type of a sub-atomic particle such as a neutrino
An international team of researchers led by Professor Adam Riess of the Space Telescope Science Institute and The Johns Hopkins University have made the most accurate measurements so far of the universe's rate of expansion following the Big Bang 13.8 billion years ago.
They discovered the universe is expanding 5 per cent to 9 per cent faster than expected.
The findings, to be published in The Astrophysical Journal, have prompted a rethink of our understanding of the universe and in particular, the concepts of dark matter and dark energy.
Normal matter such as stars, planets and gas is thought to constitute only 5 per cent of the universe.
Either something else is missing, as in there's a new type of substance we don't know, or the things we already know of are really weird and crazy and something funny is going on.
Dr Brad Tucker
The rest is 25 per cent dark matter and 70 per cent dark energy, both of which are invisible and have never been directly detected.