AUSTIN, Texas (KXAN) — A commonly held belief that the universe is rapidly expanding may be wrong. A new paper published this month suggests the universe’s expansion might be slowing down and it could mean the universe could face “The Big Crunch.”
The paper, published in Monthly Notices of the Royal Astronomical Society, comes from researchers at Yonsei University in Seoul.
Using observations from the Dark Energy Spectroscopic Instrument (DESI) in Arizona, an instrument used for to create a map of the universe, the researchers found that the brightness of some types of supernovas (Ia supernovae) may be impacted by the age of the star that blew up.
Ia supernovae are frequently called “standard candles.” Created when a white dwarf star blows up in systems that contain other stars, these supernovas are believed to have a constant amount of light. Scientists have used this constant to track the universe’s expansion.
“Younger (stars) will produce fainter supernovae compared to older (stars). And the supernovae in the distant universe are younger compared to the local count,” said Professor Young-Wook Lee, lead author on the paper, to the Associated Press.
“If you make a correction for this, only one-third of this dimming remains — that is very small,” Lee said. “So, if we take that into account, our result doesn’t match with the cosmological constant and the accelerating universe. We ended up with a decelerating universe with a time-varying dark energy.”
The dark energy between all things
Most scientists believe the universe is expanding due to dark energy, an invisible force existing between the atoms of all things that slowly pushes things apart. The discovery of dark energy earned scientists a Nobel Prize in 2011.
“Dark energy is still there, but its pressure has been weakened compared to what was previously thought. That’s the reason why the universe is not accelerating even at the present epoch, not to mention the future,” said Lee to the AP.
The end of all things
Lee says that if the universe is no longer expanding, it could lead to “The Big Crunch”, one of the many theories about how our universe would end. Essentially, the universe expands as far out as possible and then collapses in on itself, until eventually everything that ever was is reduced to a single point in space.
“Previously, it was thought that our universe would expand forever, accelerating, but now the fate of the universe can change. The fate of the universe can change! The fate of our universe is our fate, because we are all made of stardust,” Lee said to AP.
Scientist have pushed back. Dr. Adam Riess, from Johns Hopkins University and one the recipients of the 2011 Nobel Prize, told New Scientist similar arguments have been made before, but are weak because we don’t have enough data about the supernovas or the stars that form them.
The group plans to do further studies related to their findings.