Is the Universe 13.8 or 26.7 billion years old?
Our universe is actually 27 billion years old, almost double the current age estimate
According to the “Standard Model” of cosmology, the Universe is 68% dark energy, 27% dark matter, 5% normal matter, and is 13.8 billion years old: as measured since the hot Big Bang.
Recent observations from the James Webb Space Telescope (JWST), however, have found numerous galaxies that appear early, but look surprisingly grown-up. A new theory claims to solve this “early, grown-up galaxies” problem by changing the age of the Universe to 26.7 billion years old.
The question is, how that trend develops. Right now, our footprint is dropping, due to efficiency improvements. At the same time, that might change again. E.g. large scale Comms between a home world, like earth, and other planets.
There is also the problem of older civilisations. Any approaching type 2 will be VERY visible, as the spectrum of their star changes. In terms of human history, we are a long way off. In ages of the universe scales, 10,000 years is practically a blip. We see no evidence of Dyson swarms or anything of that nature. An extra 13 billion years is a LONG time for no one to leave a detectable footprint.