Friday , May 7 2021

A new study says the universe is expanding faster and is younger



The universe is expanding faster than it used to be, that is, it's a billion years younger than we thought, a new study by the Nobel laureate says. And it sends shivers through the world of physics, which makes astronomers rethink some of their most basic concepts.

The subject is a number called Hubble constant, calculating how fast the universe expands. Some scientists call it the most important number in cosmology, the study of the origin and universe of the universe.

Using NASA's Hubble Space Telescope, Johns Hopkins University astronomer Adam Reese concluded this week in the journal Astrophysical Journal that the figure is 9 percent higher than the previous calculation, based on learning from the Big Bang.

The trouble is, Reese and others think both calculations are correct.

confused? That's fine, so are the experts.

They find the conflict so confusing, because they talk about "new physics", and perhaps a particle that has not yet been discovered or other "fudge" cosmic factors, such as dark energy or dark matter.

"It looks more and more like we're going to need something new to explain it," said Reese, who won the 2011 Nobel Physics Prize.

NASA's astrophysicist John Mann, another Nobel laureate, said it leaves two clear choices: "We make mistakes we can not find yet." 2. Nature has something we still can not find.

Even with discovery, life continues on Earth as always. But the astrophysicists who are trying to deal with our place in this expanding universe is a cosmic fear.

New measurements

To raise the measurement on the Hubble constant, Reese was seen for several stars not so far away.

Reese saw 70 Cepheid stars – pulse stars at a well watched rate – calculated distance and rate, and then compared them with a specific type of supernovae used for measuring sticks. It took about two years for the Hubble telescope to perform these measurements, but in the end, Ries calculated the rate of expansion of 74.

Using the figure 74 means the universe is somewhere between 12.5 billion and 13 billion years old. This is much younger than the estimated estimates of $ 13.6 billion to $ 13.8 billion.

"Hey, that's good news, everybody likes to look younger," Reese said.

The old measurement

In 2013, the European Planck satellite helped scientists to rise with a much slower rate of expansion of 67, but this was done in a completely different, less complicated and direct way by looking at a much earlier time when the universe was only a toddler.

The Planck team studied background radiation from only 370,000 years after the Big Bang. By examining cold and hot spots in this radiation, scientists noticed how large the spots were, which helped them determine how far they were looking.

This team then consumed these calculations in the standard model that astronomers use for the universe-based on Einstein's general theory of relativity, among other things-by the known acceleration of the universe and rising with the smaller rate of expansion. The end result: a universe of 13.8 billion years.

Reese calculated the odds that the difference between the two calculations was an accident at 100,000.

Factors Fudge & # 39;

While there is a chance either the Reese team or the Planck team is off, the astronomers are talking about both being right.

The two rational calculations, "No one can find anything wrong at this point," said University of Chicago Astrophysicist Wendy Friedman. Other external experts praised the two research teams.

If this is the case, astrophysicists need to make changes to Einstein's general theory of relativity.

"You need to add something into the universe that we do not know about," said Chris Burns, an astrophysicist at the Carnegie Endowment for Science. "It always makes you feel a bit uncomfortable."

In the past, astronomers added dark dark energy and dark matter to explain why the calculations were not added, on the basis of previously abandoned Einstein theory. Now they say they have to do something similar again.

It could be another "turbocharge" from a strange pulse in the past of dark energy – an invisible expansion force that fits well in Einstein's theories – which caused an extended expansion, Reese said.

Or maybe there's a new particle of undiscovered material, Burns said.

"We have this dark sector that already has two components, and maybe we find a third," said Planck team member Lloyd Knox of the University of California, Davis. "It's a scary prospect. Are we just going to always introduce Fudge factors?"

A third approach

Astronomers at the University of Chicago, led by Friedman, spent five years looking for different stars than Reese to reach a third calculation of the rate of expansion. They simply submitted their work to the same magazine. Friedmann would not reveal her number, but said it was between the other two.

Twenty years ago, Friedman was part of a similar debate over the Hubble constant, when there were few measurements to work with.

"It's an exciting journey to try to understand the origin of the universe," she said.

[Top image: This image made from a composite of September 2003 РJanuary 2004 photos captured by the NASA/ESA Hubble Space Telescope shows nearly 10,000 galaxies in the deepest visible-light image of the cosmos, cutting across billions of light-years. /NASA, ESA, S. Beckwith (STScI), HUDF Team via AP]


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