March 3, 2024

Why It’s Very Likely The Universe Is 26.7 Billion Years Old

One cosmologist claimed that the universe is almost twice as old as conventional estimates, and his claims attracted a lot of attention. The motion would help not only with the timing of everything, but a lot with what we think we know about the development of the universe. However, he is not even close to convincing his peers.

The standard estimate of the age of the universe is 13.79 billion years, plus or minus 20 million years. Some recent comments seem to be contradicting each other. In most cases there are other explanations, but many astronomers consider it plausible that the true value could be slightly higher, at the upper end of the error bars, or slightly beyond that.

Dr. Rajendra Gupta of the University of Ottawa, however, threw out such considerations and published a paper arguing that the true age of the universe is 26.7 billion years. He calculates this using a hybrid version of an old hypothesis called “tired light” which is generally considered discredited, and modern cosmology. Enough media outlets at you jump on boarddealing with the demand largely because it is as plausible as any other peer-reviewed paper.

A much older universe would certainly explain some things, like how some of the galaxies seen by the JWST could have developed so soon after we think things started. However, Carl Sagan’s aphorism that “extraordinary claims require extraordinary proof” seems to have been made for this case, and according to other professional astrologers, Gupta has no proof at all.

“There are many measurements that suggest the age of the universe is about 14 billion years,” Professor Tamara Davis of the University of Queensland told IFLScience. “It’s not just the cosmic microwave background, it’s not just the expansion rate measured using supernovae, it’s also the large-scale structure of the universe and the measured age of the oldest stars.” At one point these seemed to be in conflict, Davis explained, with some pointing to a 9-10 billion year old universe, while others suggested 14 billion years. Now, with some reflection, all more or less agree.

“The other issue is that they’ve fitted their model to the supernova data only,” Davis continued. “It’s not good enough to tailor it to one data set and ignore all the rest.” She compared this to previous attempts to use supernova data to discredit dark energy, without testing the consequences. “They don’t even seem to have done simple things like see if their new theory of gravity breaks what we know about the orbits of the planets in the solar system,” she said.

Gupta makes many of the earliest galaxies seen by the JWST, which indeed caused some puns among the astrologers. However, Davis told IFLScience that this is partially explained. “There were difficulties with calibration with the JWST that have now been fixed,” she said. The distance to these galaxies, and therefore their age, was estimated using the relative brightness of different parts of the spectrum. As astronomers got used to the instrument, they refined their estimates to get figures more consistent with a 14 billion year universe for most of them.

Even one study to which Gupta refers, which found highly developed galaxies at very large distances in the JWST data, shows that these galaxies are very young, Davis said, and would at least push our estimates of the age of the universe slightly higher.

The oldest known star in the Milky Way, HD 140283, also known as the star Methuselah, is estimated to be 14.46 billion years old, with an error of 800 million years. However, while there is no question that HD 140283 is old, subsequent estimates were low enough to avoid any conflict with the age of the universe. Furthermore, even if the highest estimate is correct, it could add 1-2 billion years to estimates of the age of the universe, not double it.

Similarly, a recent study puts the age of the oldest globular star cluster uncomfortably close to the 13.8 billion year upper limit. If the universe were anything like the age Gupta proposed, however, one would expect to see clusters that were at least 20 billion years old, and nothing of the sort was found.

Gupta’s paper has been published in the Monthly Notices of the Royal Astronomical Society.

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