5 ms·
Wouldn't large body collisions be a fairly common occurrence in young planetary systems though? Of course any additional condition makes life rarer, I'm just t
by tifik 2y ago
Wouldn't large body collisions be a fairly common occurrence in young planetary systems though?
Of course any additional condition makes life rarer, I'm just thinking this one might not make it rarer by as many orders of magnitude as it might look like at first glance.
- jvanderbot 2y agoAnd yet - where's all the plate techtonics in our solar system? Only 1 of four inner rocky planets seems to experience it.
- jajko 2y agoOut of what, 500-1000 billions of planets just in milky way? I dont think folks do realize how big those numbers are. And there is no reason to ignore rest of the universe if we talk about probabilities and statistics
- dartos 2y agoTbh even if the number of life sustaining planets in the galaxy goes from 400B to 350B, that’s still rarer than we thought.
- jvanderbot 2y agoIt's just another fraction to multiply in the drake equation. Start with planets, cut down to rocky ones, only in habitable zone, only rotating a certain way, only with plate techtonics, etc etc. Or using your numbers, 1/4 factor eliminates 750 million possible candidates. That's not a happy thought.
- eep_social 2y agoYeah but 25% of a few hundred billion (planets in the milky way) is still a fair lot of opportunities. “Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is.”
- jvanderbot 2y agoWell I suppose it's fair to say that only 1/8 planets has plate techtonics, and AFAIK, none of the dozens of moons either.
- MPSimmons 2y agoI thought Titan did (though in that case, I think it's more ice quakes)
- mnky9800n 2y agoBut earthquakes and plate tectonics are not the same thing
- eep_social 2y agoI think the point is that we know the numerator today is one, and no matter how much you cut down the denominator, increasing the numerator to two would be a huge deal. Conversely, given that we think the denominator approaches a small infinity, it seems implausible that the numerator is actually one.
- jvanderbot 2y agoWell that's not my point. Right now the denominator is about 10 trillion. A single 1/10 factor makes it 1 trillion. 10-ish more factors and we're down to a small number of planets before we even consider the emergence of life and likelihood of propagation. There are likely many more 1/10 factors: Habitable zone, diurnal cycles, billions of years of geological peace, sufficient water, a stable moon (maybe only one), a particular spectra of the star ... all those were "well they seem to happen to 1/10 or 1/100 planets" individually. They cut down the space quickly when combined.
- irrational 2y agoBut, the 2 may be on the other side of the universe, or even past the cosmological horizon. And since FTL speed travel is almost certainly impossible, it may very well always be 1 to the best of our knowledge.
- burkaman 2y agoOnly one does at the moment, but others might have in the past. Mars: https://en.wikipedia.org/wiki/Tectonics_of_Mars https://en.wikipedia.org/wiki/Tectonics_of_Mars Venus: https://www.nature.com/articles/s41550-023-02102-w https://www.nature.com/articles/s41550-023-02102-w