Update 79, The Universe’s Hidden Tempo

Scientists have achieved something extraordinary – they’ve witnessed the early universe moving in slow motion, finally unlocking one of Einstein’s most profound mysteries.

Einstein’s general theory of relativity proposes that the distant, ancient universe should appear to run at a much slower pace than our present-day reality. While this idea has intrigued researchers for decades, peering so far back in time seemed nearly impossible. But now, a team of brilliant minds has cracked the code, and the key lies in the enigmatic quasars.

Quasars, those celestial superstars, are hyperactive supermassive black holes situated at the hearts of early galaxies. Emitting intense energy and light, they act as cosmic beacons illuminating the distant past. These powerful objects have become the secret “clocks” that unlock the secrets of time dilation.

Imagine looking back over a billion years, watching the universe’s infancy unfold in what appears to be slow motion. But here’s the mind-bending twist – if we were actually present during that epoch, time would flow just like it does today. It’s the fascinating effect of Einstein’s theory in action!

Led by Professor Geraint Lewis from the School of Physics and Sydney Institute for Astronomy at the University of Sydney, along with collaborator Dr. Brendon Brewer from the University of Auckland, the team made their groundbreaking discovery using data from nearly 200 quasars observed over two decades.

Previously, scientists relied on supernovae, those colossal exploding stars, to serve as “standard clocks” for measuring the slow-motion universe. However, observing these stellar explosions from such vast distances posed significant challenges.

Enter the quasars, with their ongoing firework display of brilliance. Unlike supernovae, quasars continuously emit light, making them easier to study. Professor Lewis and Dr. Brewer analyzed various colors and wavelengths of light emitted by these celestial wonders, enabling them to standardize the ticking of each quasar.

Employing Bayesian analysis, the researchers revealed the universe’s expansion imprinted on each quasar’s ticking, taking us back to a mere tenth of the universe’s current age. This newfound insight confirms Einstein’s vision of an expanding universe and settles debates surrounding the nature of quasars as cosmic objects.

The implications of this groundbreaking discovery are profound, allowing us to peer further back into the universe’s history and gain deeper insights into the cosmos’ evolution.


On the 3rd of July, 2023, this groundbreaking research paper was officially published in the acclaimed journal, Nature Astronomy. (Lewis, G.F., Brewer, B.J. Detection of the cosmological time dilation of high-redshift quasars. Nat Astron (2023). https://doi.org/10.1038/s41550-023-02029-2)