Very exciting news, I'm hoping that it is proof of life as that will give increase interest and funding for space exploration.
See also the Silurian Hypothesis [0], which I think just got a lot more interesting as a thought experiment.
[0]: https://www.theatlantic.com/science/archive/2018/04/are-we-e...
Betteridge's Law confirmed. We can track down fossils billions of year back by observing the way they shaped the encasing rocks, and not once have we noticed a ceramic shard, a metal bit or the silhouette of a plastic object.
> There are fossils, of course. But the fraction of life that gets fossilized is always minuscule and varies a lot depending on time and habitat. It would be easy, therefore, to miss an industrial civilization that lasted only 100,000 years—which would be 500 times longer than our industrial civilization has made it so far.
Sandstones. Sandstones originate as far as hundreds of million years in the past. Occasionally they harbor fossils, which are indeed rare. But a lot of sandstone is made of sanded up organic material which we can readily identify, even if we can't point to the specific organism they originated from. We only need a tiny industrial-related grain of sand (ceramic, glass, metal, plastic traces) to point to a past civilization. Nobody ever noticed such a grain of sand.
> So it might take both dedicated and novel detection methods to find evidence of a truly short-lived event in ancient sediments. In other words, if you’re not explicitly looking for it, you might not see it. That recognition was, perhaps, the most concrete conclusion of our study.
I'm not bullish on pre-historic civilization, and neither is the article, but the takeaway is we may not have reason to expect that we'd have found these tiny industrialized traces without a search aimed specifically at them. As far as I know, such searches have not been carried out in earnest to date.
So not a truly short-lived event in ancient sediments then.
Here's a good read on the subject: https://waitbutwhy.com/2014/05/fermi-paradox.html
For the same reason the large dinosaurs died out. Life as we know it operates best within fairly narrow mass scales and energy level ranges. Those are both several orders of magnitude away from the quantities needed to produce effects observable at interstellar distances.
The universe should be teeming with life but isn't.
We currently have no good evidence that it is. That doesn't mean it isn't, just that our detection methods aren't yet up to the challenge. Basic information theory suggests that they may never be. Advanced civilizations will use coherent EM radiation for a limited time only. The radiation they do generate in the long term probably won't be wasted by letting it escape isotropically into space.
Also, at some point they may come to understand that drawing attention to themselves isn't a good survival strategy. A civilization that is advanced enough for us to observe is also advanced enough to hide from us.
Not really true. There are more signs of life than just radio waves. One - like in the article - is chemistry. Planets that seem to be very far from chemical equilibrium are objects of interest, as this may imply there is a complex system that's actively fighting entropy. I.e. life. For instance, aliens with powerful telescopes and good understanding of geology could conclude Earth has life on it by observing it keeps a surprising amount of oxygen in the atmosphere, where it should have already oxidized everything instead.
Admittedly Earth's oxygen signature would be a lot easier to detect than a minute quantity of PH3 on Venus. But we wouldn't have been able to look for that either until just a few years ago. Even to a seasoned RF engineer, ALMA and JCMT are indistinguishable from magic.
If we assume life is abundant in the Universe, then we should be able to pick up signs of others, such as radio signals, or bio-indicators in other planets' atmospheres, and so, we ask where the aliens are.
Since we don't find any, we then assume that there is something preventing this abundance of life from developing into something we can detect, and something's called the Great Filter.
As of yet, we only have a single point of data, and since we're still here there's some speculation that we've allready passed through the filter. Another data point would mess up the math a bit and we could, statistically speaking, end up with a scenario meaning we still haven't passed the filter, and that we might still have an apocalyptic event wiping us out.
Life on Venus would give us a better idea of what to look for in other places, and that might help us narrow down the search a bit and find other places with life.
Intelligent life is a different matter. We don't know how common it is for
1) a planet to have formed around a star with the right composition of materials 2) have the exact right conditions for life to form early 3) for that life to survive for billions of years while 4) building up large reserves of substances that can 5) be used as fuel by a tool using bunch of talking apes 6) propel their civilization's technology far enough to match ours 7) send a signal that can reach our specific little dot 8) for that signal to be reach us during the miniscule time-frame that we've been able to pick it up.
I mean, what if the glory days of the Milky Way was 500 million years ago and we're developed just a little to late to be able to see the last remnants of galactic civilization crumble to dust? What if we just happen to be the first, and we develop past such technology before anyone else develops it?
That leaves these possible obvious filters: single cell to multicellular life or planetary resources exhaustion.
Evolution of eukaryotes from prokaryotes is a more plausible bottleneck. (Disclaimer: I am not an expert on any of this.)
We're a matter of years from originating von Neumann machines ourselves, so any civilization with thousands or millions of years head start should have incredible galactic spread.
No, we're saying that that life didn't even reach "civilization". Humans are a blip in time compared to the dinosaurs, for example - we may well be the anomaly, but life still be abundant.
https://www.nytimes.com/2020/04/28/us/pentagon-ufo-videos.ht...