Scientists have gained a glimpse into the early days of the universe, when it was about 1 billion years old, and discovered that things were moving in slow motion compared to the present day. This finding supports Albert Einstein’s general theory of relativity, which suggests that the distant universe moved much slower in the past.
Studying the early universe, formed by the Big Bang about 13.8 billion years ago, is an incredibly challenging task due to the immensity of the universe. The reach of sophisticated telescopes, which observe different wavelengths of light, can only extend so far through the cosmos. Therefore, scientists turned to a phenomenon that can serve as a kind of celestial calendar: a quasar.
A quasar, or hyperactive supermassive black hole located at the center of a primitive galaxy, is so luminous that it shines 100 times brighter than our Milky Way. This brightness acts as a cosmic clock that researchers can use to track time in the universe. Observing quasars over time allowed a team of astronomers to check how the universe seemed to accelerate as it aged.
The observation of 190 quasars over two decades provided insights into how the universe appeared to slow down during its infancy. These observations, captured at different wavelengths of light, seemed to “tick” like clocks. The astronomers also looked at supernovas, or explosions of massive stars, as another type of cosmic clock that allowed them to track the slow-motion movement of the universe until about half of its current age. Although very bright, supernovas are much more difficult to observe at greater distances from Earth, so astronomers needed another source that was visible deeper into the early universe.
The study’s co-author, Dr. Brendon Brewer, a professor of statistics and astrostatistician at the University of Auckland, conducted an analysis of the 190 observed quasars. The researchers were able to unravel the complex “fireworks” display of quasars and demonstrate that they can be used as standard time markers for the early universe.
The expansion of the universe is another key aspect explored in the study. Research has shown that the universe is expanding at an accelerated rate, which scientists are still trying to understand. Discovering what happened in the early universe can help scientists unravel the greatest mysteries about its origin, evolution, and future.
“Thanks to Einstein, we know that time and space are intertwined and that since the dawn of time in the singularity of the Big Bang, the universe has been expanding,” explains Geraint Lewis, the lead author of the study and a professor of astrophysics at the University of Sydney. “This expansion of space means that our observations of the early universe should appear much slower than the current flow of time. In this work, we have established this to be true until about 1 billion years after the Big Bang.”
The study’s findings provide valuable insights into the nature of the early universe and its evolution over time. By understanding how time appeared to flow in the past, scientists can better grasp the fundamental laws of the universe and gain a deeper understanding of its overall structure and development.
The research, published in the journal Nature Astronomy, highlights the importance of studying celestial objects and phenomena as a way to uncover the secrets of the universe. By utilizing quasars and supernovas as cosmic clocks, astronomers can piece together the puzzle of the early universe and shed light on its mysteries. This knowledge not only advances our understanding of the cosmos but also contributes to the broader field of astrophysics.
With each new discovery, scientists inch closer to unraveling the complex and awe-inspiring nature of the universe. The study of the early universe and its dynamics provides valuable insights into the fundamental workings of the cosmos and offers a glimpse into the origins of everything we see today.
As technology and observational techniques continue to improve, astronomers will undoubtedly make further breakthroughs in understanding the early universe. The quest to unlock the secrets of the universe’s infancy is an ongoing journey that fuels scientific curiosity and pushes the boundaries of human knowledge. Through these discoveries, scientists can continue to shape our understanding of the cosmos and our place within it.
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