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On 06/03/2020 16:32, John K Clark wrote:<br>
<blockquote type="cite"
cite="mid:mailman.79.1583512359.23370.extropy-chat@lists.extropy.org"><font
size="4">Galactic clusters are the largest structures in the
universe held together by gravity and the Ophiuchus Supercluster
contains 4021 known galaxies, it's likely none of them contain
life, much less intelligent life. Telescopes have seen evidence
that the largest galaxy in the center of the cluster underwent a
gargantuan explosion at least 240 million years earlier, it's
390 million light years away so the explosion happened at least
630 million years ago. It's thought that 270 million solar
masses of gas and dust was sucked into the black hole at the
center of the galaxy producing something equivalent to a
supernova going off every month for a 100 million years.
Something like that would probably sterilize not only the galaxy
but the entire cluster. And Ophiuchus is relatively nearby so
it's almost certain there are more distant clusters that
suffered even larger explosions. It looks like the Milky Way has
just been lucky.</font>
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<div><a
href="https://www.icrar.org/wp-content/uploads/2020/02/2002.01291.pdf"
moz-do-not-send="true">DISCOVERY OF A GIANT RADIO
FOSSIL IN THE OPHIUCHUS GALAXY CLUSTER</a><br>
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<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><font size="4">
John K Clark</font></div>
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</blockquote>
<br>
I'm wondering what are the chances that something similar will
happen in our neighbourhood sometime in the future?<br>
<br>
If it does, what could our future selves do to survive it?<br>
<br>
There's a story by Greg Egan that has a similar premise. It's not
encouraging.<br>
<br>
<pre class="moz-signature" cols="72">--
Ben Zaiboc</pre>
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