Scientists have for the first time measured how time flowed five times slower in the early universe, just a billion years after the Big Bang.
Key Takeaways
- Quasars act as cosmic ‘clocks,’ revealing the early universe was five times slower than today’s time.
- Using nearly 200 quasars, scientists have unlocked the mystery of time dilation in the infant universe.
- Einstein’s theory of general relativity predicts an expanding universe, and quasars confirm this through their time ‘ticks.’
- Previously, time dilation was observed back to half the universe’s age using supernovae; quasars extend this to a tenth of its age.
- Through Bayesian analysis, researchers standardized the ‘tick’ of quasars to measure the influence of expanding space on time.
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For the first time, scientists have measured the early universe running in extreme slow motion, showing that time was five times slower just a billion years after the Big Bang. By studying nearly 200 quasars – hyperactive supermassive black holes at the centers of ancient galaxies – researchers have provided new evidence for Einstein’s theory of general relativity regarding an expanding universe.
The Mystery of Early Universe Time Dilation
Einstein’s general theory of relativity predicts that, as the universe expands, distant objects (and therefore the early universe) should appear to experience slower time. However, directly observing this has been challenging due to the vast distances and the faint signals coming from early cosmic phenomena. Previous research had established this dilation back to half the age of the universe using supernovae, but quasars have now pushed this further back to just a tenth of the universe’s age.
Professor Geraint Lewis and Dr. Brendon Brewer utilized data collected over two decades from quasars, observing variations in light at different wavelengths (green, red, and infrared). These observations were standardized using Bayesian analysis to determine how the expanding space influenced the quasar ‘ticks.’ This detailed examination revealed that quasars provide a reliable cosmic ‘clock’ for measuring the dilation of time in the infant universe.
Implications of Time Dilation and Expanding Space
The research provides further confirmation of Einstein’s expanding universe model, offering more support to the idea that space itself is expanding. By comparing the observed ‘ticks’ of quasars to predictions made by general relativity, researchers demonstrated that quasars behave as expected when it comes to the effects of expanding space on time.
Previous studies questioned whether quasars were truly cosmological objects or whether the expansion of space was accurately understood. However, the current study has resolved these uncertainties, proving that quasars act as reliable cosmic markers of time dilation.
The results could have significant implications for understanding how the universe evolved and how its expansion influences the formation of structures like galaxies and black holes. This breakthrough not only enhances our understanding of the universe’s infancy but also supports broader cosmological theories involving space-time dynamics.
The use of quasars as ‘clocks’ for early universe research has opened new avenues for studying the universe’s distant past. As data collection and analysis improve, scientists anticipate uncovering even more precise insights into the behaviors of cosmic phenomena and how the universe continues to evolve.
This study is published in Nature Astronomy.
