I suspect it's the other way around, really: it might be really hard to develop out of the early stages without hitting a reset button. Yes, we're destroying the planet at the moment and it remains to be seen if we learn quickly enough. However, the first cyanobacteria repeatedly caused global mass extinction events by poisoning the atmosphere with oxygen for over 800 million years until something evolved that could breathe that poisonous molecule[0]. That is almost one fifth of the entire age of Earth.

What if the odds that most planets are trapped in early development of life for the entire time that it can support life are just really really big?

[0] https://www.patheos.com/blogs/daylightatheism/2009/02/bands-...

I think this is also a likely cause, the odds that life even develops beyond the microscopic level, plus the fact that civilizations probably don't last that long combined with the scale of the cosmos and the light speed limitation means that it's unlikely that two civilizations even become aware of each other.

Still, I think it's a bit surprising that no signs of former life have been found so far in both Mars and Venus especially, and even elsewhere in our solar system like on certain moons.

There are definitely lots of hints that there is live in Mars, but not a smoking gun yet. https://en.wikipedia.org/wiki/Life_on_Mars#Possible_biosigna...

I always wonder how our own evolution affects our long term chances of survival as an intelligent species. Homo sapiens only exists 30K years and until recently survival was hard, making it an advantage to be intelligent. But our recent technological and medical advances make survival more and more easy so in terms of evolution, other biological features become more useful, such as for instance the rate of reproduction. So suppose we keep improving our life standard like we have been doing so far, how will humans as a species develop over the next, say, one million years?

I think biology itself provides us with some clues of what is likely to happen. There have been other species in the past that because of climatological or geological changes suddenly had a very easy time surviving. Take the Dodo for instance. What happened to them is that they gradually lost most of the survival features that they didn't need anymore. Perhaps this is the future of any intelligent life form and maybe this is why we don't detect any sign of them in the universe.

> Homo sapiens only exists 30K year

You meant 300k, right? The problem is, the human species is growing at an exponential rate, so if this continues and it's going to be hard not to, the damage tho the ecosystem can go very fast as there are processes that can also be triggered in an exponential manner.

For example, melting of the ice cap would cause not only ocean rise but a lot more heat staying in the planet as ice reflects a lot of it back into space.

Also, a temperature rise of 5 degrees would kill most phytoplankton, which is the main source of oxygen.

All of this sounds very catastrophic, but it might be somewhere in between a few centuries and a few millennia away, which is nothing on a geological time scale.

The current equilibrium that allows for human life on this planet is much more fragile than we think.

While I think we should reduce our footprint on our ecosystem, I doubt we could do enough damage to eradicate life by blowing away the atmosphere or using all oxygen and nitrogen that basically only carbon dioxide remains - not even with American cars.

The more probable scenario would be that humans destroy the foundation of their own food chain until the population starts to decline in a catastrophic manner. But that seems to be the case for any type of mammal that experienced a significant population grow.

Of course human with their adaptability would damage a lot of biodiversity in the process of "dying out".

The truth is that Mars and Venus are comparatively "shit" even while fitting some conditions as "worlds like Earth", even if their signatures while being swallowed by a white dwarf would be very similar.

But the article is true and there could indeed be a lot of other blue marbles given the size of the cosmos.

Due to the exponential rise of the human population, which shows no signs of slowing down, it might go quite fast.

There are many geological processes that get triggered in an exponential way and can radically change the ecosystem.

For example, melting a part of ice cap means less heat gets reflected back into space, meaning more heat that will further melt more ice cap, etc. a potential positive feedback mechanism that once triggered cannot be controlled.

I think that at this point we're pretty confident that there have never been any advanced civilizations on Mars. We'd see their chemical and isotopic residues.

Here's a good talk on filters: https://www.youtube.com/watch?v=k7fLNvpl0c8

Not an expert here, but after a billion years, what would be the detectable residues of such civilization could realistically be detected?

I mean everything made of organic material would be gone, and all constructions would have been turned to dust.

Not saying that there was anything ever in Mars or Venus in terms of intelligent life, but non-intelligent life what traces would it leave?

>all constructions would have been turned to dust

I don't think that's true. There are detailed structured fossils and strata on Earth that are billions of years old, and our planet is geologically active with much more weather erosion.

> There are detailed structured fossils and strata on Earth that are billions of years old

Yes but that is not detectable from space, right? Also in Mars for example, without excavating specifically for fossils which I think hasn't been done yet, is there a way like certain geological structures that would remain intact after a billion years that would indicate life?

Likely radioactive substances that were once in large amounts with long half-lives

For example, we are now moving away from nuclear due to the dangers associated, so we only have it for less than 100 hundred years.

The half-life of uranium is 4.5 billion years. Let's say civilization of earth is wiped out and someone visits the planet a billion years from now.

Could they tell that there was something here just by the levels of uranium, assuming that say we only used it for 200 years before moving fully to clean energy?

A billion years is a long time. But if they came in a million, they probably could - if not from radioisotopes, then just from observing that the surface layer composition of metals doesn't fit any reasonable geological model. We dug up a lot of stuff, and while this initially concentrates them, as our works decay, they get dispersed into the environment, and I doubt a million years is enough for them to reintegrate back into the crust.

But wouldn't those substances be buried deep in the soil 1 billion years later? Or in the case of Earth with all the plate tectonics, entire plates could be already inside Earth's mantle.

steroids

Or maybe they also go the bellow replacement level population growth like we do know, and they never recover, they simply die out. The tough conditions that created an intelligent species are simply not there after that species changed its environment "for the better", the species cannot evolve fast enough to catch up with its capabilities and the species dies out. Maybe all intelligent life strives for comfort, but once comfort is achieved, it just kills of the species that created it.

Uninhabitable. Inhabitable is like inflamable.