Washington: The universe is expanding faster than it used to, meaning it’s about a billion years younger than we thought, a new study by a Nobel Prize winner says. And that’s sending a shudder through the world of physics, making astronomers re-think some of their most basic concepts.

At issue is a number called the Hubble constant, a calculation for how fast the universe is expanding. Some scientists call it the most important number in cosmology, the study of the origin and development of the universe, reports the UNB.

Using NASA’s Hubble Space Telescope, Johns Hopkins University astronomer Adam Riess concluded in this week’s Astrophysical Journal that the figure is 9% higher than the previous calculation, which was based on studying leftovers from the Big Bang.