That’s a good point. The precise degree of metal-poorness matters here. In fact, lower levels of carbon, silicon and phosphorus make life in general probably less likely to form, much less civilization. And almost all complex life involves some other elements to some extent (copper, iron and selenium are common examples).
And even if you had pure CHNOPS life on a planet with just say CHNOPS, and some iron, nickel and silicon in large quantities, then it is plausible that you wouldn’t get to advance much at all. The problem is that you don’t need large amounts of other chemical elements to get into space, so as long as you have enough to get to something close to our tech level, you might be ok. One possible related barrier though is a lack of fossil fuels to help bootstrap a civilization- but this only adds at most around fifty million or a hundred milliion or so to the minimum time frame.
But overall, your point seems to be strong: this may be an example where the Drake Equation’s highly approximate nature (essentially treating all planets the same) is making a severe estimation error and we shouldn’t consider such planets at all relevant for Filter discussions.
That’s a good point. The precise degree of metal-poorness matters here. In fact, lower levels of carbon, silicon and phosphorus make life in general probably less likely to form, much less civilization. And almost all complex life involves some other elements to some extent (copper, iron and selenium are common examples).
And even if you had pure CHNOPS life on a planet with just say CHNOPS, and some iron, nickel and silicon in large quantities, then it is plausible that you wouldn’t get to advance much at all. The problem is that you don’t need large amounts of other chemical elements to get into space, so as long as you have enough to get to something close to our tech level, you might be ok. One possible related barrier though is a lack of fossil fuels to help bootstrap a civilization- but this only adds at most around fifty million or a hundred milliion or so to the minimum time frame.
But overall, your point seems to be strong: this may be an example where the Drake Equation’s highly approximate nature (essentially treating all planets the same) is making a severe estimation error and we shouldn’t consider such planets at all relevant for Filter discussions.