
Exploding stars may have caused mass extinction on Earth: study - dnetesn
https://phys.org/news/2020-08-stars-mass-extinction-earth.html
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brainless
Here is the original paper titled "Supernova triggers for end-Devonian
extinctions" by Brian D. Fields and others:

[https://www.pnas.org/content/early/2020/08/17/2013774117](https://www.pnas.org/content/early/2020/08/17/2013774117)

~~~
JoeAltmaier
They speak of

"a 300,000-year decline in biodiversity leading up to the Devonian-
Carboniferous mass extinction"

Is this a real thing? I ask, because paleontologists have had a bad record of
interpreting statistical samples around an event. I.e. misinterpreting the
mean interval between the last recorded fossil before an event as evidence of
'gradual extinction'.

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tribeofone
There is never a bad time to plug Egan on HN. Diaspora is one of his novels
around just this topic. If you decide to read it, strap in, you're going for a
mind bending ride.
[https://www.goodreads.com/book/show/156785.Diaspora](https://www.goodreads.com/book/show/156785.Diaspora)

~~~
netcraft
Another recommendation for this book - I am pretty sure its my favorite
fiction novel and I have read it many times. So many interesting and thought
provoking parts.

~~~
sosuke
I feel that rereading a book is the height of praise. So you've hooked me I'm
going to pick up Diaspora.

Returning the favor I've reread "A Fire Upon the Deep" a few times now. Vernor
Vinge scifi author who taught comp sci and mathematics at university.

~~~
RobertoG
I like Vinge very much, but Egan is really in another level.

I have read Diaspora three times and I can't decide if I like it more than my
favorite other book by him: Permutation City.

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simonh
It looks like there's no risk from this now as there are no supernova
candidates near enough to have that strong an effect. With stellar drift
though. That could change in the course of tens or hundreds of millions of
years with stellar drift.

What could we do to mitigate this though. Would enclosed habitats, greenhouses
and pastures covered by UV blocking screens be enough to maintain habitability
and a sustainable agriculture?

~~~
Nursie
> That could change in the course of tens or hundreds of millions of years
> with stellar drift.

Not worth worrying that much about it then - in a mere billion years (IIRC)
the sun's output is predicted to have increased enough that it's unlikely
liquid water could exist on the surface of the earth, effectively ending most
life. Though it's possible that the level of CO2 in the atmosphere will have
dropped enough to make photosynthesis impossible for most plants in around
half that time.

~~~
yourapostasy
So we only have about 500 megayears to both attain a K2 scale civilization and
find a way to use that power to protect our cradle world (or work around the
extinction of life as we know it). Got it. No pressure.

~~~
EForEndeavour
Bear in mind that our species has only existed for a rough upper limit of 500
KILOyears. The first electric motor was built only ~200 years ago, and we've
only been technically spacefaring for ~60 years. We went from first heavier-
than-air flight to first space station in 70 years.

Our species has a thousand times our current age to figure things out. To
unironically quote Dennis Reynolds from _It 's Always Sunny_: we haven't
peaked. We haven't even _begun_ to peak.
([https://www.youtube.com/watch?v=tS7ifk26tJc](https://www.youtube.com/watch?v=tS7ifk26tJc))

~~~
simonh
I’m afraid I don’t see it that way. Technologies don’t improve exponentially
for ever, they follow an S curve. The physical properties of the universe are
fixed and finite. Eventually we will discover all the technologies that are
practical, and we may not be all that far from doing so. Maybe only a few
hundred years, and we may be quite far along the S curve of some of the best
of them.

~~~
yourapostasy
While I think there is an "S" curve, I see we have quite a lot more to learn,
much longer than a few hundred years' worth. I'd say more on the order of
hundreds of millennia more at a minimum, because the scales I see possible are
so vast. My metric is where we are on the Kardashev scale, how resilient we
are to extinction-level events, and our time horizon. The ultimate "we're
pretty close to knowing all the practical stuff" level being figuring out how
to work around the entropic end of the universe. I count indefinite life
extension among the practical tech tree, and once we accomplish that, the
range of "practical" also expands.

Even before all that, we're nowhere close to various practical limits we've
calculated as theoretically possible in energy extraction, energy conversion,
energy conservation, matter properties (compression strength, tension
strength, torsion strength, and so on), computational density, information
density, _etc._

For most of our species' history in geological time, we've barely edged over
from sentience to sapience. On that scale, we're still at the boundary layer
edge, and have yet to really delve into and establish ourselves within the
time stream into sapience.

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rbanffy
After the initial UV/X/Gamma hit, we'd have a good couple thousands of years
to build a parasol to protect us from the slower particles.

~~~
londons_explore
You and I both know that any event that is 1000 years away nobody will put any
effort into protecting against today...

And in 1000 years, humans will have forgotten the XRay blast (do you remember
the mysterious plague of 1020AD where lots of people died of cancer? No -
didn't think so...), and therefore won't prepare.

~~~
wing-_-nuts
>do you remember the mysterious plague of 1020AD where lots of people died of
cancer?

I'd love to have a source on this? Particularly in relation to cancer rates at
the time? I googled but the only thing I could find was a ref to an outbreak
of bubonic plague in germany in 1022AD.

~~~
asah
Prev author was being facetious / too clever by half, note the exact date of
1020 and the lack of "/s" :-)

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danieldrehmer
What about the fringy hypothesis of solar mini-novas to explain the
extinctions?

Would appreciate some thoughts on the plausibility of this.

There’s a growing internet movement of people pushing this and they sound
geekier than your usual conspiracy theorist.

~~~
sgt101
We can see very large populations of sun like stars, and there are no
observations of this kind of behaviour, so it seems unlikely. The large full
sky survey telescopes coming on-line in the next few years will rule this out
our in after a decade or so though. If billion sun like stars are watched for
five years at least fifty should pop in a micro nova if the theory has any
legs.

~~~
KKPMW
As far as I am aware there are observations of this behaviour. Several are
listed here:
[https://en.wikipedia.org/wiki/Nova#Recurrent_novae](https://en.wikipedia.org/wiki/Nova#Recurrent_novae)

~~~
cowboysauce
Are any of those from sun-like stars? The ones listed all seem to involve
white dwarfs.

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novalis78
Add a bullet point to Boring company’s mission plan.

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lolc
Nice how they provide testable predictions (radioisotope signatures) for their
theory.

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rhacker
It's great to see articles like this. but I encourage people to treat things
like this, and the other thread making rounds about how all the stars that
have been made are most that will ever be made as having a chance of being
correct at 0.000001%. Not that this percentage isn't an amazing breakthrough,
but just don't turn this into - the debate is settled in 5 years.

