For much of this decade, the two most precise gauges of the Universe’s rate of expansion have been in glaring disagreement. Now, a highly anticipated independent technique that cosmologists hoped would solve the conundrum is instead adding to the confusion.
In results unveiled on 16 July and due to appear in the Astrophysical Journal, a team led by astronomer Wendy Freedman at the University of Chicago in Illinois presents a technique that measures the expansion using red-giant stars. It had promised to replace a method that astronomers have been using for more than a century—but for now, the speed measurement has failed to resolve the dispute because it falls half way between the two contentious values.
“The Universe is just messing with us at this point, right?” tweeted one astrophysicist about the paper.