The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. As a 2015 article put it, “If life is so easy, someone from somewhere must have come calling by now.”
cynar@lemmy.world 3 months ago
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.
XeroxCool@lemmy.world 3 months ago
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.
cynar@lemmy.world 3 months ago
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.