Rendering alam semesta dari Quasar “Clocks” 5 kali lebih lambat setelah Big Bang

Data pengamatan dari hampir 200 quasar menunjukkan bahwa Einstein benar – sekali lagi – tentang perluasan waktu alam semesta.

Para ilmuwan telah memperhatikan untuk pertama kalinya bahwa alam semesta awal bergerak dalam gerakan yang sangat lambat, membuka salah satu misteri alam semesta yang mengembang milik Einstein.

Teori relativitas umum Einstein berarti bahwa kita harus mengamati jauh – dan karenanya kuno – alam semesta bekerja jauh lebih lambat daripada yang dilakukannya saat ini. Namun, melihat kembali ke masa itu terbukti sulit dipahami. Para ilmuwan kini telah mampu memecahkan misteri ini dengan menggunakan kuasar sebagai “jam”.

kata penulis utama studi tersebut, Profesor Geraint Lewis dari Fakultas Fisika Universitas Sydney dan Institut Astronomi Sydney.

“Jika Anda berada di luar sana, di bayi alam semesta ini, satu detik akan terasa seperti satu detik — tetapi dari lokasi kita, lebih dari 12 miliar tahun ke depan, waktu awal itu tampaknya semakin tertunda.”

Penelitian ini diterbitkan 3 Juli di astronomi alam.

Profesor Geraint Lewis berada di Institut Astronomi Sydney di Fakultas Fisika Universitas Sydney. Kredit: Universitas Sydney

Profesor Lewis dan rekan penulisnya, Dr Brendon Brewer dari University of Auckland, menggunakan data yang diamati dari hampir 200 quasar – lubang hitam supermasif di pusat galaksi awal – untuk menganalisis pelebaran waktu ini.

“Berkat Einstein, kita tahu bahwa ruang dan waktu terjalin, dan sejak awal waktu dalam singularitas Big Bang, alam semesta telah mengembang,” kata Profesor Lewis.

“Perluasan ruang ini berarti bahwa pengamatan kita terhadap alam semesta awal seharusnya tampak jauh lebih lambat daripada arus waktu hari ini.

“Dalam makalah ini, kami membuktikannya kembali sekitar satu miliar tahun kemudian[{” attribute=””>Big Bang.”

Previously, astronomers have confirmed this slow-motion universe back to about half the age of the universe using supernovae – massive exploding stars – as ‘standard clocks’. But while supernovae are exceedingly bright, they are difficult to observe at the immense distances needed to peer into the early universe.

By observing quasars, this time horizon has been rolled back to just a tenth the age of the universe, confirming that the universe appears to speed up as it ages.

Professor Lewis said: “Where supernovae act like a single flash of light, making them easier to study, quasars are more complex, like an ongoing firework display. 

“What we have done is unravel this firework display, showing that quasars, too, can be used as standard markers of time for the early universe.”

Professor Lewis worked with astro-statistician Dr. Brewer to examine details of 190 quasars observed over two decades. Combining the observations taken at different colors (or wavelengths) – green light, red light, and into the infrared – they were able to standardize the ‘ticking’ of each quasar. Through the application of Bayesian analysis, they found the expansion of the universe imprinted on each quasar’s ticking.

“With these exquisite data, we were able to chart the tick of the quasar clocks, revealing the influence of expanding space,” Professor Lewis said.

These results further confirm Einstein’s picture of an expanding universe but contrast earlier studies that had failed to identify the time dilation of distant quasars.

“These earlier studies led people to question whether quasars are truly cosmological objects, or even if the idea of expanding space is correct,” Professor Lewis said.  

“With these new data and analysis, however, we’ve been able to find the elusive tick of the quasars and they behave just as Einstein’s relativity predicts,” he said.

Reference: “Detection of the cosmological time dilation of high-redshift quasars” by Geraint F. Lewis and Brendon J. Brewer, 3 July 2023, Nature Astronomy.
DOI: 10.1038/s41550-023-02029-2