I’m a proponent of the Rare Intelligence Hypothesis for the Fermi Paradox, amount with this. I suspect common Great Filters include of the problem is the amount of heavier elements in sufficient quantities not being high enough, especially phosphorous which is still fairly rare in most parts of the galaxy; waterbound intelligence unable to utilize fire for metal refining and other purposes; heavier gravity making rockets impossible and even mass-driver gravity well escapes difficult; the fact that advanced intelligence is a really rare even after 4 billion years on earth and has so far only produced 1 lasting advanced tool using species that has passed into the stone age, much less past it; and cyclically self-destructing civilizations that ultimately burn through the resources necessary to escape the planet in any meaningful way.
Cyclical self-destruction is basically reaching nuclear war or other planetary deviation tech, loosing a few centuries or millennia of progress, rinse and repeat until you can’t leave the planet. I lump anthropic climate catastrophe in there. Hard to get the population and tech up to space-age when you’ve made 90% of your planet uninhabitable.
I’m a proponent of the Rare Intelligence Hypothesis for the Fermi Paradox, amount with this. I suspect common Great Filters include of the problem is the amount of heavier elements in sufficient quantities not being high enough, especially phosphorous which is still fairly rare in most parts of the galaxy; waterbound intelligence unable to utilize fire for metal refining and other purposes; heavier gravity making rockets impossible and even mass-driver gravity well escapes difficult; the fact that advanced intelligence is a really rare even after 4 billion years on earth and has so far only produced 1 lasting advanced tool using species that has passed into the stone age, much less past it; and cyclically self-destructing civilizations that ultimately burn through the resources necessary to escape the planet in any meaningful way.
Cyclical self-destruction is basically reaching nuclear war or other planetary deviation tech, loosing a few centuries or millennia of progress, rinse and repeat until you can’t leave the planet. I lump anthropic climate catastrophe in there. Hard to get the population and tech up to space-age when you’ve made 90% of your planet uninhabitable.