The Universe Is Expanding Faster Than Expected

_{Image: NASA, ESA, Adam Riess, & Palomar Digitized Sky Survey}

A team of scientists has reported a 9% discrepancy between the observed expansion of the universe today and the expansion of the universe from shortly after the Big Bang. The team used the new DASH, Drift And SHift, method to rapidly observe the Cepheid variables using Hubble. The Cepheid variables are regularly fluctuating stars that are used as a known constant by which to measure distances within the universe. Rather than being constrained to studying only one star per 90 minute orbit, DASH works by turning Hubble into a still shot camera that takes photos of numerous stars at once. The researchers then combined their data with another team's data, allowing them to improve the accuracy of their measurements before calculating the Hubble constant. The group managed to drop the uncertainty in the measured rate of universal expansion done to 1.9%, with hopes to reduce it further to 1%.

Adam Riess, the team leader, stated: "This is not just two experiments disagreeing. We are measuring something fundamentally different. One is a measurement of how fast the universe is expanding today, as we see it. The other is a prediction based on the physics of the early universe and on measurements of how fast it ought to be expanding. If these values don't agree, there becomes a very strong likelihood that we're missing something in the cosmological model that connects the two eras."

Read more: Johns Hopkins University