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And passing through a local galaxy spiral arm...
http://curious.astro.cornell.edu/physics/55-our-solar-system...
Ok, so they're saying[1] 1 Sv every 30 years. That's 33 mSv a year. Meanwhile, according to [2], "160 mSv: chronic dose to lungs over one year smoking 1.5 packs of cigarettes per day, mostly due to inhalation of Polonium-210 and Lead-210". I'm pretty sure heavy smokers are still reproducing successfully.
Even if the muon-dose theory is true, it doesn't amount to an extinction-level event for a single species. Cancer takes time to develop; sometimes it doesn't. When the muon flux goes away, life would resume as normal. It might contribute to an extinction event already in progress, but that is not the same thing. And there is a lot of if, if, if in this hyopthetical.
“Larger and longer-lived organisms will experience a greater relative increase in radiation dose” 30 mSv does not have that high of a risk to a human, but with 50+ times as much tissue the cancer risks would be vastly higher for whales. A 1% risk in humans might be a 50% risk in a whale species.
Further, specific tissues receiving radiation only increases the risk to those tissues. A sunburn does not increase your risk of lung cancer. Making a x mSv exposure to your lungs less risky than that same exposure to your entire body.
PS: Heavy smokers also don’t start in infancy. If they did they would be dying ~20 years sooner.
If your conjectures were true elephants would be dying of cancer all the time. In fact elephants are much more cancer resistant than humans due to differing biology. The whole "more tissue, more disease" part of this is bunkum.
I don’t disagree, but we lack direct evidence for how resident these animals where to radiation.
Water is a great shield vs most kinds of radiation as is their bulk which means these animals may have significantly lower resistance. Worse they would still be getting ~1SV over 30 years at ~1km below the oceans let alone the few feet of their bodies. Which is vastly above background radiation levels.
I agree, interesting but pretty weak theory.
Other events, like north and south america coming together changing global currents and weather systems, seem much more likely to cause catastrophe for marine life.
Would the same dose of radiation not be more harmful for a large animal than a person, since there's more volume being affected by it?
Edit: just looked it up, a sievert is already per mass.
And Mass grows faster than surface (which seems relevant for irradiation) , so probably larger animals might be less affected.
streamed through the atmosphere and fatally irradiated megafauna like the monster shark megalodon
...
They get to the ground, they hit you, and some of them will interact with you, and damage your DNA, Melott said. “They are in a sweet spot for affecting ground-based life.
Shark ... ground based life. Eh?
Are muons attenuated by water?
> mutations killed megalodon and other big animals
Well, first of all sharks are famous for being extra-resistent to developping cancer. They are superconservative in its structure and did not changed practically its shape in the last 100 millions of years. If there are a creature that is practically un-mutable are sharks.
Second, the theory claims that big sharks where killed by muons but whales where somehow respected. Why the animals able to find refuge in deep waters (that stop muons) were wiped, but the animals that need to remain in the ocean surface are alive?
Third, trees are also huge organisms, for some reason weren't wiped. Why?
and fourth, big animals trive in Chernobill even with radiation.
I think that as hypothese is interesting but it has a lot of loose ends to explain.