The Hubble Space Telescope has taken new measurements that have confirmed that the Universe is expanding about 9% faster than expected based on the trajectory seen shortly after the big bang. The new measurements were published this week and reduce the chances of the new measurements being an accident from about 1 in 3,000 to 1 in 100,000.
Scientist Adam Riess has stated that the mismatch has been growing and has now reached the point where it’s “really impossible” to dismiss as a fluke. Riess and his team analyzed light from 70 stars in our neighboring galaxy, the Large Magellanic Cloud, using a new method that allowed for the capture of quick images of the stars.
The stars are known as Cepheid variables and brighten and dim at predictable rates that are used to measure intergalactic distances. The old method of measuring the stars was time-consuming because the Hubble could only observe one star for every 90-minute orbit around the Earth.
Using the new measurement method, the team was able to observe a dozen Cepheids in that same amount of time. The new measurement data was used to strengthen the foundation of the cosmic distance ladder used to determine the distance in the Universe and to calculate the Hubble Constant. The Hubble Constant is a value of how fast the cosmos expands over time.
The Hubble measurement was combined with another set of observations may be the Araucaria Project. That project made distance measurement to the Large Magellanic Cloud by observing the dimming of light as one star passes in front of its partner in binary-star systems. As the measurements became more precise with the new data, the Hubble constant has remained at odds with expected values. Riess says it’s not just two experiments disagreeing noting that the two projects are measuring something fundamentally different.