Emily Chan
Recently, the James Webb Space Telescope (JWST) has taken new measurements, and the results have only caused more confusion about our understanding of the universe, particularly the Hubble tension. According to the findings, the phenomenon may not exist at all.
The Hubble tension refers to how the current rate of expansion of the universe is faster than astronomers expect it to be based on the universe’s conditions and evolutionary history.
Depending on where astronomers look, the universe seems to be expanding at different speeds. Some of the measurements align with what we know about the universe, but others threaten to uproot that understanding altogether.
In 2022, a team of researchers used the space telescope to confirm that the Hubble tension exists. However, the latest findings from another group of scientists have suggested that the Hubble tension may have emerged from measurement error and does not actually exist. Still, even these results are not conclusive.
“Our results are consistent with the standard model. But they don’t rule out that there’s a tension there too,” said Wendy Freedman, the lead author of the study and an astrophysicist at the University of Chicago. “[The experience] is probably the closest thing to a rollercoaster—it’s been exciting, but there are these moments when you’ve got to climb the hill again.”
There are two methods for figuring out the Hubble constant, which is a value that describes the expansion rate of the universe.
The first method involves examining the tiny fluctuations in the cosmic microwave background, remnants of the universe’s first light, which was produced about 380,000 years after the Big Bang.
After taking the measurements, experts deduced a Hubble constant of approximately 46,200 miles per hour per million light-years.
The second method uses pulsating stars called Cepheid variables, closer distances and information from the universe’s later life. Cepheid stars are slowly dying celestial bodies. As their outer layers of helium gas expand and contract, absorbing and releasing radiation, they flicker on occasion.
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