大爆炸后，类星体“时钟”对宇宙的渲染速度慢了 5 倍

来自近 200 个类星体的观测数据表明，爱因斯坦对于宇宙时间膨胀的看法再一次是正确的。

科学家们首先注意到宇宙以极其缓慢的速度运行，解开了爱因斯坦膨胀宇宙的谜团之一。

爱因斯坦的广义相对论意味着我们应该观察到遥远的——因此也是古老的——宇宙的运行速度比今天慢得多。 然而，回顾当时的情况却令人难以捉摸。 科学家们现在已经能够通过使用类星体作为“时钟”来解开这个谜团。

该研究的主要作者、悉尼大学物理学院和悉尼天文研究所的杰兰特·刘易斯教授说。

“如果你在外面，在这个婴儿宇宙中，一秒看起来就像一秒——但从我们的位置来看，在未来超过 120 亿年的时间里，那个早期的时间似乎被推迟了。”

该研究发表于 7 月 3 日 自然天文学。

杰兰特·刘易斯教授是悉尼大学物理学院悉尼天文研究所的教授。 图片来源：悉尼大学

Lewis 教授和他的合著者奥克兰大学的 Brendon Brewer 博士使用了近 200 个类星体（早期星系中心的超大质量黑洞）的观测数据来分析这种时间膨胀。

刘易斯教授说：“多亏了爱因斯坦，我们知道时间和空间是交织在一起的，自从大爆炸奇点出现以来，宇宙一直在膨胀。”

“空间的膨胀意味着我们对早期宇宙的观测应该比今天的时间流动慢得多。

“在这篇论文中，我们证明了这一点可以追溯到大约十亿年后[{” attribute=””>Big Bang.”

Previously, astronomers have confirmed this slow-motion universe back to about half the age of the universe using supernovae – massive exploding stars – as ‘standard clocks’. But while supernovae are exceedingly bright, they are difficult to observe at the immense distances needed to peer into the early universe.

By observing quasars, this time horizon has been rolled back to just a tenth the age of the universe, confirming that the universe appears to speed up as it ages.

Professor Lewis said: “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.”

Professor Lewis worked with astro-statistician Dr. Brewer to examine details of 190 quasars observed over two decades. Combining the observations taken at different colors (or wavelengths) – green light, red light, and into the infrared – they were able to standardize the ‘ticking’ of each quasar. Through the application of Bayesian analysis, they found the expansion of the universe imprinted on each quasar’s ticking.

“With these exquisite data, we were able to chart the tick of the quasar clocks, revealing the influence of expanding space,” Professor Lewis said.

These results further confirm Einstein’s picture of an expanding universe but contrast earlier studies that had failed to identify the time dilation of distant quasars.

“These earlier studies led people to question whether quasars are truly cosmological objects, or even if the idea of expanding space is correct,” Professor Lewis said.  

“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,” he said.

Reference: “Detection of the cosmological time dilation of high-redshift quasars” by Geraint F. Lewis and Brendon J. Brewer, 3 July 2023, Nature Astronomy.
DOI: 10.1038/s41550-023-02029-2