The Universe’s Rapid Expansion Rates and Riess’s New Study

This month, cosmologists express their concerns as the universe keeps on expanding at increasingly fast speeds. At first, the signs of changes remain too small to serve as threats. Now, however, there is something seriously wrong with people’s usual understanding of space. According to Stockholm University’s cosmologist Edvard Motsell, the problem with the latest accurate measurements of the cosmos seemed impossible to shove off. Due to these rapid changes, cosmologists are at a loss for finding answers behind the universe’s spiraling extension.

A new study shows that astronomers may have to revise their theories of how the cosmos work by integrating several latest physics. The latest research reveals that compared to the universe’s short trajectories not long after Big Bang, the updated expansion rate is about 10% faster in speed. Additionally, the study significantly minimizes the possibility that this is a discrepancy by chance, transitioning from 1 in 3,000 to only 1 in 1,000.

To further back up the said findings, John Hopkins University professor and study lead author Adam Riess explained in an issued statement that the growing mismatch finally reached its limit. Due to that discovery, researchers can no longer ignore such disparity.

In the late 1990s, Riess showed that the universe had begun its accelerated expansion. Many people still wonder what caused the unexpected gain in momentum. However, Astronomers proposed the possibility that a mysterious, repulsive force called “dark energy” brings about the baffling rapid changes in the cosmos.

While conducting the new study, Riess and his associates studied the Large Magellanic Cloud’s (LMC) 70 Cepheid variable stars using the Hubble Space Telescope. Astronomers can compute distances by using Cepheid variables. “Standard candles” is another name used to call Cepheid orbs due to their predictable dimming and brightening charges. Moreover, another type of standard candle exists, known as the Type 1 supernovae, that allows scientists to estimate reaches even into space’s farther corners. The Type 1a supernovae research made by Riess, Perlmutter, and Schmidt won them a Nobel Prize award for their discovery.

The Araucaria Project and Cosmos’ Current Expansion Rate

Additionally, Riess and his colleagues integrated observations made by the Araucaria Project into their study. The previously mentioned project aimed to analyze various LMC binary star systems involving the collaboration of researchers coming from Chile, Europe, and the United States. According to the said outline, a star that passes in front of its neighboring orb causes the former’s light to dim. Due to this, Riess’s study team enhanced their comprehension of the Cepheids’ inherent brightness by reviewing the project’s additional distance measurements.

With all the previously mentioned information obtained from the Araucaria Project, the researchers used this to compute the cosmos’ current expansion rate, a value also known as the Hubble constant (named after Edwin Hubble, an American astronomer). 

According to the researchers, the uncertainty attached to the previously mentioned number is only 1.9%, marking it as the present day’s lowest computed uncertainty value. The 2009 calculations showed 5%, while the 2001 figures revealed 10%

Expected Expansion Rates and Riess’s Conclusion

By variance, the “expected” expansion rate is 41.9 miles per second per megaparsec. The predicted figure heavily based its observations on the cosmic microwave background of Europe’s Planck satellite. The said phenomenon refers to what happened 13.82 billion years ago when Big Bang’s leftover light formed the universe we know today. In response to these findings, Riess concluded that the two conducted experiments measured something fundamentally different from one another. Additionally, he explained that they might have missed something in the cosmological model that connects the two eras due to the values not coinciding with one another.

The Astrophysical Journal published Riess’s and his team’s latest study on April 25, 2019.