Astronomers Are Baffled To Find That the Universe Is Expanding Too Fast; 'Not What We Expected'
Astronomers routinely discover a multitude of new things regarding the ever-expansive world beyond. In 2019, a new finding about the dimensions of the universe stunned the experts, stated Science Daily.
NASA's Hubble Space Telescope collected certain measurements that implied the universe is expanding at a faster rate than previously expected. The assertions were made based on the subjects captured by the Hubble Space Telescope. Initially, this disparity was considered to be an accident, but the measurements produced by the telescope indicated that the chance of it being a mistake was 1 in 100,000. "This mismatch has been growing and has now reached a point that is really impossible to dismiss as a fluke. This is not what we expected," said Adam Riess, Bloomberg Distinguished Professor of Physics and Astronomy at The Johns Hopkins University, Nobel Laureate, and the project's leader.
Reiss collaborated with his SH0ES (Supernovae, H0, for the Equation of State) team to examine the data gathered by the telescope. They took into consideration light captured by the telescope from 70 stars present in the Large Magellanic Cloud, a neighboring galaxy. These stars labeled as Cepheid variables brighten and dim following an expected pattern. These patterns helped experts in determining intergalactic distances.
This examination was not feasible in the past, but a new feature called DASH (Drift And Shift) allowed experts to observe around a dozen stars at the same time that it would have taken to analyze one star in the past. All of this made the examination swifter in comparison. The bubble data was combined with the details collected by the Araucaria Project, a coalition of experts from institutions in Chile, the U.S., and Europe. The combined information helped astronomers figure out the true brightness of the concerned stars.
The data helped experts gain more insights into the cosmic distance ladder — a set of methods experts utilize to determine the distances of different bodies in the universe. These measurements became more precise but was no surprise. The surprise happened when the facet of expansion showed some unexpected behavior. The researchers used all the insights and previous data to determine the Hubble constant, a value indicating the expansion of the universe over the years.
In the past, the expansion rate was determined through the data garnered by the European Space Agency's Planck satellite. The satellite captured the universe's trajectory and scientists predicted how the universe would expand. "This is not just two experiments disagreeing," Riess explained. "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."
The team was yet to understand why these differences existed. Reiss was determined to continue working on the data and reduce the uncertainty regarding the Hubble constant from 1.9% to 1%. Another recent study by Reiss confirms that the universe is not expanding according to the previous models. "We're at a point where we're pressing really hard against the models we've been using for two and a half decades, and we're seeing that things aren't matching up," said Daniel Scolnic, lead author of the study, stated Science Daily. "This may be reshaping how we think about the Universe, and it's exciting! There are still surprises left in cosmology, and who knows what discoveries will come next?"