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> TL;DR: our Sun's bumpy orbit through the spiral arms of out galaxy means periodic increases of comets and other bodies being jarred loose and later hitting Ea
by flukus 10y ago
> TL;DR: our Sun's bumpy orbit through the spiral arms of out galaxy means periodic increases of comets and other bodies being jarred loose and later hitting Earth, resulting in mass extinctions.
Isn't only one of the mass extinctions (the dinosaur ending one) somewhat tightly linked to a comet impact? It seems as though it's finding a pattern that does no fit the data.
- metaobject 10y agoI believe a few of the mass extinctions are thought to have been caused by gamma ray bursts (GRBs) that were close enough to earth to either affect the atmosphere or the orgamisms on the surface.
- mcv 10y agoAre the causes of other mass extinctions known? I can imagine comet impacts can be hard to trace over billions of years. Especially when it's not just a single big one, but a period of increased impacts. Also, I believe the dinosaur extinction was not just a comet impact, but a combination of an impact and a period of increased volcanic activity. Could the volcanic activity be triggered by comets? I think the jury is still out, but it's an interesting field of study across many different fields (astronomy, biology, geology and probably more), and it has obvious implications for humanity's future on Earth, in space, and the chances of finding other life out there.
- flukus 10y ago> Could the volcanic activity be triggered by comets? That's an interesting question. My completely unqualified opinion would be no, an comet couldn't trigger the massive and ongoing volcanic activity that a mass extinction requires. I'd like to hear from someone more informed though.
- cifvts 10y agoCould a big enough comet impact cause the Earth behave like a liquid and therefore a wave destabilize the crust and increase volcanic events?
- interfixus 10y agoI live not too far from the Danish location Stevn Klint, a chalk cliff formation where the Alvarez'es found one very neat exhibit for their case. Utterly fascinating: You can climb to the foot of the cliffs, and there, unmistakable and obvious, is the dark, horizontal line in the massive wall of white - you can see it, you can touch it, and you can ponder the very different nature of fossil below and above the line. There is a local museum rigth next to the cliffs. A few years ago, I spoke to the leader there, a woman with a ph.d. in history, who more or less supplied the final death blow to any lingering respect I might have held for any kind of humanities: Her only take on Walter and Louis Alvarez and their world famous work in her own backyard was how of course they were so arrogant, they had raised hostility among scientists and everybody else the world over.
- selimthegrim 10y agoArrogant about what?
- interfixus 10y agoI took it to be a humanities view of being out of whack with concensus.
- posterboy 10y agowhat's that to do with anything in the thread