> Scientists have confirmed that just 1.5 billion years after the Big Bang, time ran five times slower than it does today, 13.8 billion years later. Though scientists have long been aware that conditions just after Big Bang were radically different than those in the cosmos we see around us today, the discovery shows that time is relative in regards to the age of the Universe, too, just like Einstein predicted.
https://www.newscientist.com/article/2380881-time-appears-to... (paywalled)
https://www.sciencealert.com/time-appears-to-have-run-5-time...
https://www.advancedsciencenews.com/time-ran-slowly-in-the-e...
> Scientists have confirmed that just 1.5 billion years after the Big Bang, time ran five times slower than it does today, 13.8 billion years later. Though scientists have long been aware that conditions just after Big Bang were radically different than those in the cosmos we see around us today, the discovery shows that time is relative in regards to the age of the Universe, too, just like Einstein predicted.
The referenced paper: https://www.nature.com/articles/s41550-023-02029-2