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.
To further add to this. The concern is related to what is nicknamed “the great filter”. The drake equation tries to estimate the number of communicating civilisations within range of us. Even with quite pessimistic terms, it still implies there should be lots of them. Therefore, a term is likely missing or wrong. This is known as the great filter.
If the great filter is behind us, that’s fine. E.g. abiogenesis being vastly harder, and so less likely, than we think. However, it could also be ahead of us. If it is, it likely won’t be far. We are already entering the era where we are detectable on an interstellar distance. Nukes and climate change have been raised as potential “great filters”.
An alternative idea is that we are not typical. If we are one of the first civilisations to reach this level, at least locally, then we would see very little. An older universe makes this significantly less likely.
An interesting point about the radio visibility of our civilization is that it was incredibly short lived. Sure, we have some unique items that may be visible if specifically searched, such as radiation or organic chemical signatures/ratios. But the whole thing about blasting space with radio and TV signals? Basically just a 100 year stint. Current devices are much more focused, so there’s less spill, and by going digital, identifiable waveforms are much rarer. We went form nothing, to being the social media addict of the solar system, to blending back into the static in a matter of a century.
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.
You nailed a thing I think many miss. Our signals will be static soon, and I don’t care what kind of magical tech aliens have. Static is static, truly random noise.
And as a civilization progresses, less and less need for EMF broadcast. Think fiber vs. AM radio. Maybe we’ll hit a tech point where, for whatever reason, we broadcast more EMF, dunno.