The universe could be expanding up to as much as 9 per cent faster than first thought, according to a study from the University of California, Berkeley.
The team said it has made the "most precise measurement yet" of the rate of the universe's expansion, despite the fact this contradicts previous predictions.
This either means our measurements of background radiation - the "leftover glow" from the Big Bang - are wrong, or that "an unknown physical phenomenon is speeding up the expansion of space".
"If you believe our number - and we have shed blood, sweat and tears to get our measurement right and to accurately understand the uncertainties - then it leads to the conclusion there is a problem with predictions based on measurements of the cosmic microwave background radiation," said Alex Filippenko, a Berkeley professor and co-author of the study.
"Maybe the universe is tricking us, or our understanding of the universe isn’t complete," he added.
The rate of expansion has raised questions about our measurements of this radiation, and may suggest either the existence of an "unknown particle" or that the "influences of dark energy" has increased over the past 13 billion years.
Even more controversially, the team suggest its "surprising" discovery may mean Einstein's theory of relativity is "slightly wrong".
"This finding may be an important clue to understanding those mysterious parts of the universe that make up 95 percent of everything, and don't emit light, such as dark energy, dark matter and dark radiation," said Adam Riess, leader of the study and professor at Johns Hopkins University.
The team observed galaxies containing two types of stars - Cepheids and Type 1a supernovae.
"Cepheid stars pulsate at rates that correspond to their true brightness, which can be compared to their apparent brightness as seen from Earth," the team explain. "This can accurately determine their distance and thus the distance of the galaxy."
This technique, which they call "innovative", is able to improve the precision of distance measurements of objects that are many light years away.
Around 2,400 Cepheid stars were observed during the course of the study.
"We needed both the nearby Cepheid distances for galaxies hosting Type Ia supernovae and the distances to the 300 more-distant Type Ia supernovae to determine the Hubble constant," said Riess.
"If we know the initial amounts of stuff in the universe, such as dark energy and dark matter, and we have the physics correct, then you can go from a measurement at the time shortly after the Big Bang and use that understanding to predict how fast the universe should be expanding today," said Riess.
"However, if this discrepancy holds up, it appears we may not have the right understanding, and it changes how big the Hubble constant should be today."
This article was originally published by WIRED UK
