While some of us are concerned about our own rate of expansion, scientists have been studying the universe’s rate of expansion for the better part of a century.
Last week’s collision of two neutron stars continues to give cosmologists new insights—including information about how fast the universe is expanding, a much-contested number called the Hubble constant. Since that cosmic collision, Hubble experts are now wondering just how quickly the new info might help them settle the controversy. Since 1929, when American astronomer Edwin Hubble showed that the universe is expanding (and therefore has a beginning), scientists have debated about the exact rate of expansion—a rate known as the Hubble constant. Nailing down that precise rate will help scientists pinpoint the age of the universe and other matters, and will help them better understand all things cosmological.
Right now, scientists’ best estimates at the Hubble constant vary as much as 8%, “currently the biggest tension in cosmology,” said Dan Scolnic of the University of Chicago’s Kavli Institute for Cosmological Physics. But the data being gleaned from last week’s neutron star merger will help narrow that gap, if not close it completely.
This new article from Quanta magazine goes into detail about what scientists are learning from that cosmic event.
Image: Artist’s rendition of colliding neutron stars, courtesy of Fermilab.