The birth of the universe is shrouded in guesses and hypotheses. Now, the mystery deepens as scientists believe that their previous estimate for the age of the universe was off -- by over a billion years -- upending one of the few things scientists felt certain about.
According to NBC News, the findings reveal that researchers will also have to reevaluate their theories as to how the universe formed after the Big Bang.
The discovery happened after a number of teams, such as one headed by Nobel laureate Adam Riess of the Space Telescope Science Institute in Baltimore, looked to verify the results calculated by the Planck space telescope.
The cause of the discrepancy is the Hubble constant, which calculates how fast the universe is expanding by dividing the speed of other galaxies moving away from Earth by their distance from Earth. Per The Associated Press, some scientists have called the Hubble constant the "most important number in cosmology."
The Planck method estimated the age of the universe by studying background radiation from spots that developed 370,000 years after the Big Bang. Researchers used temperature variations in the different radiation spots to determine how far away the spots were.
When they put those calculations in with the rate of the expanding universe, they came up with an age of around 13.8 billion years.
Riess, however, used a different method: He and his team instead measured the distance of 70 Cepheid stars. The results suggested a universe that was much younger at 12 to 13.5 billion years. They also suggested the universe is expanding much faster.
Riess expressed his confusion at the conflicting data, per NBC.
"The discrepancy suggests that there's something in the cosmological model that we're not understanding right."
Many scientists believe in a brain-twisting theory that both calculations could be correct. Some are coining the term "new physics" for squaring away the two results; others believe that dark energy or dark matter may be influencing how the universe behaves by issuing "turbocharges."
"Nobody can find anything wrong at this point," agreed astrophysicist Wendy Freedman from the University of Chicago, admitting that both calculations seemed correct.
NASA astrophysicist John Mather, another Nobel winner, said to the AP that results have two different interpretations.
"1. We're making mistakes we can't find yet. 2. Nature has something we can't find yet."