ronflair

ronflair t1_jdskzk1 wrote

Reply to comment by Octavus in Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger? by somethingX

You still would get a net increase in surface ionizing radiation, which would increase as a positive feedback loop the longer the magnetosphere was “off”.

According to NASA, a prolonged loss of the magnetosphere could erode the protective layers of the atmosphere. More cosmic rays would reach the surface as well.

https://science.nasa.gov/science-news/news-articles/earths-magnetosphere

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ronflair t1_jdsiy99 wrote

Reply to comment by zanderkerbal in Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger? by somethingX

As a molecular biologist, It just seemed like an obvious connection to me given the time frame. I have not googled the hypothesis but if geologists have noted years ago that the magnetic field was severely weakened during that geologic era, I would be surprised if no evolutionary biologist noted the connection. That said, I don’t see that mentioned as a hypothesis for the Cambrian explosion on wikipedia.

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ronflair t1_jdscqhs wrote

Reply to comment by PolymerPolitics in Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger? by somethingX

Depends on the depth. According to this site, a water layer 7cm thick reduces ionizing radiation dosage by about half.

https://space.stackexchange.com/questions/1336/what-thickness-depth-of-water-would-be-required-to-provide-radiation-shielding-i

If correct, means that cyanobacterial mats inhabiting the top layers of oceans will still be receiving significantly more ionizing radiation than normal. We’re not talking about enough radiation to sterilize the planet, just enough to significantly increase the rate of mutagenesis.

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ronflair t1_jds7p7s wrote

Reply to comment by mcnessa32 in Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger? by somethingX

On the contrary, coincidentally it corresponds with the Cambrian Explosion, when all multicellular organisms and phyla arose. Before that, for billions of years, everything was mainly unicellular, such as cyanobacteria; afterwards, dinosaurs, trees, mammals, humans etc.

https://en.m.wikipedia.org/wiki/Cambrian_explosion

Could a severely weakened magnetic field have lead to a massive increase in mutagenesis globally, essentially jumpstarting a new evolutionary arms race? Maybe. We do use radiation and other mutagens to do just that in the laboratory.

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ronflair t1_iwmmhs6 wrote

Reply to comment by egregiouscodswallop in New psychology research rebuts Sigmund Freud's "wrecked by success" hypothesis: People with exceptionally successful careers tend to be healthier than their less successful peers by HeinieKaboobler

He also personally used his success to buy and use cocaine. A lot. He really really loved cocaine.

https://www.pbs.org/newshour/show/cocaine-how-miracle-drug-nearly-destroyed-sigmund-freud-william-halsted

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