For the 1st time expansion of the Universe is seen in slow motion – 7/5/2023 – Science
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Scientists observed for the first time that in the early Universe, time passed “five times slower”.
They analyzed data from quasars – objects powered by “supermassive” black holes at the center of the first galaxies – and used them to measure time shortly after the beginning of the Universe.
Quasars are among the brightest and most distant celestial bodies known.
Astrophysicist Geraint Lewis, a professor at the University of Sydney, Australia, told the BBC that this confirms once again that we live in an expanding universe.
“Looking back to a time when the Universe was just over a billion years old, we see that time seems to flow five times slower [logo após o Big Bang]”, says Lewis, lead author of the study published in the scientific journal Nature Astronomy.
“If you were there, in this early universe, a second would seem like a second – but from our position, over 12 billion years in the future, that initial time seems to drag.”
Quasars are bright objects powered by “supermassive” black holes that spew energy as they fill with gas, dust and other matter within their gravitational reach, according to NASA, the US space agency.
Lewis and astrostatistician Brendan Brewer of the University of Auckland in New Zealand analyzed the colors of nearly 200 quasars over 20 years. They were then able to standardize the “ticking” of each quasar.
In explaining what all this means, the researchers said that it confirms the expectation of Albert Einstein’s theory of general relativity – which is to say that we should observe the distant Universe working much more slowly than it does today.
“Thanks to Einstein, we know that time and space are intertwined, and since the beginning of time in the Big Bang singularity, the Universe has been expanding,” he says. “This expansion of space means that our observations of the early Universe should appear much slower than how time flows today.”
“In this paper, we established that this goes back to about a billion years after the Big Bang.”
The university said astronomers had previously verified the slow-motion motion of the Universe at up to about half its current age using supernovae – exploding massive stars. But quasars allowed Professor Lewis and his team to confirm the theory even further, reaching a tenth of the age of the Universe.
“As far as we know, the expansion will continue, and the Universe will get bigger and emptier,” he added to BBC Radio 4’s Today programme.
This text was originally published here.
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