In a groundbreaking discovery, astronomers have confirmed Albert Einstein's theories about the expansion of the universe and the relative nature of time.
Observations of quasars, luminous objects formed from supermassive black holes feeding on gas at the centers of distant galaxies, have revealed that time appeared to move five times slower in the early universe than it does today. This phenomenon, known as time dilation, was observed in the universe when it was just one billion years old, less than a tenth of its current age.
The concept of time dilation, where time runs slower in the early universe, was proposed by Einstein in the late 1920s. As light from distant galaxies travels from the dense early cosmos across the continuously expanding universe, time becomes stretched. This means that a clock running 10 billion years ago would appear to be ticking much slower from our perspective today.
This discovery was made possible by studying the flickering glows of quasars, which are formed by supermassive black holes feeding on gas at the centers of distant galaxies. The researchers observed 190 quasars, covering a range of cosmic time from about 2.5 billion to 12 billion years ago. The findings confirm that quasars in faraway galaxies ticked slower than ones in the later, nearby universe, with time dilation making those most distant appear to run at a glacial one fifth of the standard speed.
This study not only validates Einstein's theories but also opens up new avenues for exploring the nature of dark energy, the mysterious force thought to be responsible for the acceleration in the universe's expansion. The researchers believe that accurate timestamping of ancient quasars could be instrumental in further understanding the universe's expansion in greater detail.