{"id":47132,"date":"2023-07-04T13:48:08","date_gmt":"2023-07-04T13:48:08","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=120043"},"modified":"2023-07-04T14:32:33","modified_gmt":"2023-07-04T14:32:33","slug":"astronomers-observe-the-very-early-universe-running-in-slow-motion","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/astronomers-observe-the-very-early-universe-running-in-slow-motion\/","title":{"rendered":"Astronomers observe the very early Universe running in slow motion"},"content":{"rendered":"

Using cosmic clocks known as ‘quasars’, a team of astronomers perceive the early Universe running much slower than the present day. <\/p>

By Iain Todd\n \t\t<\/p>

Published: Tuesday, 04 July 2023 at 12:00 am<\/p>

\n\n

The deeper astronomers peer into space, the further back in time they can observe, right back to the very early Universe, just after the Big Bang.<\/p>\n

And according to Einstein\u2019s general theory of relativity, when looking back into the ancient Universe, we should perceive time running much slower than the present day.<\/p>\n

Achieving this slow-motion view of the very early cosmos has proven tricky, but a team of astronomers say they\u2019ve been able to do just that, by observing high-energy black hole<\/a> objects known as quasars<\/a>.<\/p>\n

\""Professor\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Professor Geraint Lewis from the University of Sydney, Australia.<\/span><\/figcaption><\/div>\n

\u201cLooking back to a time when the Universe was just over a billion years old, we see time appearing to flow five times slower,\u201d says lead author of the study, Professor Geraint Lewis from the University of Sydney<\/a>.<\/p>\n

\u201cIf you were there, in this infant Universe, one second would seem like one second \u2013 but from our position, more than 12 billion years into the future, that early time appears to drag.\u201d<\/p>\n

The research has been published in Nature Astronomy<\/a>.<\/p>\n

To make the observations, the team studied data from nearly 200 quasars. These objects are hyperactive black holes at the centres of galaxies<\/a>.<\/p>\n

\u201cThanks to Einstein, we know that time and space are intertwined and, since the dawn of time in the singularity of the Big Bang<\/a>, the Universe has been expanding,\u201d Professor Lewis says.<\/p>\n

\u201cThis expansion of space means that our observations of the early universe should appear to be much slower than time flows today.<\/p>\n

\u201cIn this paper, we have established that back to about a billion years after the Big Bang.\u201d<\/p>\n

\""Illustration\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Illustration showing the expansion of the Universe from the Big Bang to the present day.Credit: Andreus \/ iStock \/ Getty Images Plus<\/span><\/figcaption><\/div>\n

Looking back further in time<\/strong><\/h2>\n

Previously, astronomers had been able to observe the \u2018slow motion\u2019 Universe back to about half the age of the Universe by analysing supernovae<\/a> \u2013 the explosive end of massive stars\u2019 lives.<\/p>\n

These events can be used as \u2018standard clocks\u2019 to reveal time slowing down in the early Universe.<\/p>\n

However, by using quasars instead, this latest discovery has seen astronomers observe the slow motion back to a tenth of the age of the Universe.<\/p>\n

\u201cWhere supernovae act like a single flash of light, making them easier to study, quasars are more complex, like an ongoing firework display,\u201d says Professor Lewis.<\/p>\n

\u201cWhat we have done is unravel this firework display, showing that quasars, too, can be used as standard markers of time for the early Universe.\u201d<\/p>\n

\""A\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
A Hubble Space Telescope image of a pair of quasars that existed when the universe was just 3 billion years old. Dual quasar J0749+2255 is embedded inside a pair of colliding galaxies. Credit: NASA, ESA, Yu-Ching Chen (UIUC), Hsiang-Chih Hwang (IAS), Nadia Zakamska (JHU), Yue Shen (UIUC)<\/span><\/figcaption><\/div>\n

How they did it<\/strong><\/h2>\n

Professor Lewis collaborated with Dr Brendon Brewer from the University of Auckland<\/a> on the discovery to examine data from the large batch of quasars over two decades.<\/p>\n

They were able to combine observations captured at different wavelengths of light to standardise the regular \u2018tick\u2019 of each quasar.<\/p>\n

They were then able to compare how the quasars should be behaving with their actual observed behaviour to measure the expansion of the Universe via each quasar\u2019s ticking.<\/p>\n

\u201cWith these exquisite data, we were able to chart the tick of the quasar clocks, revealing the influence of expanding space,\u201d Professor Lewis says.<\/p>\n

\u201cEarlier studies led people to question whether quasars are truly cosmological objects, or even if the idea of expanding space is correct.<\/p>\n

\u201cWith these new data and analysis, however, we\u2019ve been able to find the elusive tick of the quasars and they behave just as Einstein\u2019s relativity predicts\u201d.<\/p>\n

Video explainer<\/strong><\/h2>\n

This 30-second primer from the University of Sydney reveals the mind-blowing physics behind the new study.<\/p>\n