[ExI] Gaian Bottleneck

[BillK]

On 21 January 2016 at 17:35, Dan TheBookMan  wrote:
> http://phys.org/news/2016-01-aliens-silent-theyre-dead.html
> The problem is to accurately judge whether this is enough and not too much.
>
> I was also thinking about Medea Hypothesis in relation to this. That
> wouldn't be a bottleneck, but a deadly positive feedback loop. Then again, I
> guess you could say each Medean event was a bottleneck. See:
> https://en.m.wikipedia.org/wiki/Medea_hypothesis
>

Smithsonian points to dangerous radiation in the early universe.

<http://www.smithsonianmag.com/science-nature/where-are-all-aliens-taking-shelter-universes-radiation-180957901/>

Quote:
Where Are All the Aliens? Taking Shelter From the Universe's Radiation
Earlier life-forms across the cosmos may have faced thousands to
millions of times the cosmic ray dose that we do today.
A new analysis of cosmic evolution suggests that planets in the early
universe were slammed with bursts of radiation thousands to millions
of times higher than Earth has ever faced. That's because black holes
and star formation were more vigorous during these epochs, and
everything in the universe was also much closer together, allowing for
denser doses of radiation than planets face today.
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BillK