In an exciting breakthrough, scientists have observed the early universe operating in an extreme state of slow motion, shedding light on one of the mysteries of Einstein's expanding universe. This discovery was made possible by using quasars, the supermassive black holes at the centers of early galaxies, as "clocks" to measure time during the universe's infancy.
Lead author of the study, Professor Geraint Lewis from the School of Physics and Sydney Institute for Astronomy at the University of Sydney, explains, "Looking back to a time when the universe was just over a billion years old, we see time appearing to flow five times slower. If you were there, in this infant universe, one second would seem like one second, but from our position, more than 12 billion years into the future, that early time appears to drag."
This groundbreaking research has been published in Nature Astronomy and provides significant evidence supporting Einstein's general theory of relativity, which predicts that the distant and ancient universe should appear to run slower than the present day. However, observing such distant time periods has posed a challenge until now.
By utilizing observed data from nearly 200 quasars, hyperactive supermassive black holes located at the centers of early galaxies, Professor Lewis and collaborator Dr. Brendon Brewer from the University of Auckland successfully analyzed the phenomenon of time dilation. Quasars allowed the scientists to extend the time horizon back to just a tenth of the universe's age, confirming the notion that the universe appears to accelerate as it ages.
Explaining the significance of their findings, Professor Lewis states, "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."
The team meticulously examined data from 190 quasars observed over two decades, employing various wavelengths ranging from green light to red light and the infrared. Through Bayesian analysis, they were able to standardize the "ticking" of each quasar and deduce the impact of the universe's expansion on their observations.
These remarkable results further bolster Einstein's depiction of an expanding universe, countering previous studies that failed to identify the time dilation of distant quasars. Professor Lewis concludes, "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."
