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On 2016-09-16 19:20, John Clark wrote:<br>
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cite="mid:CAJPayv2pMHFOikckeQFpp-DJ-y-atZSy4Z79TxMgB0jSy6pa0Q@mail.gmail.com"
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<div class="gmail_default"
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n Fri, Sep 16, 2016 at 3:59 PM, BillK <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:pharos@gmail.com"
target="_blank">pharos@gmail.com</a>></span> wrote:<br>
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0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">1)
Tabby's star has one or more partially constructed Niven
Rings.<br>
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<div class="gmail_default"
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size="4">But what are those </font></div>
<font size="4">Niven Rings
<div class="gmail_default"
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made of? Yes I know u</div>
nobtainium
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but the trouble is the only thing that would have
sufficient tensile strength to build such a ring would
be the degenerate matter that make up Neutron Stars,
and there would be 2 problems with using that:</div>
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Neutronium may also be be a superfluid (strictly speaking it is
different from degenerate matter, which can be solid). The always
amusing A.A. Bolonkin has some calculations on nuclear density
composites:<br>
<a class="moz-txt-link-freetext" href="http://docsdrive.com/pdfs/sciencepublications/ajeassp/2009/501-514.pdf">http://docsdrive.com/pdfs/sciencepublications/ajeassp/2009/501-514.pdf</a><br>
He estimates a tensile Young's modulus of 1.6*10^32 N/m^2. If one
could make his composite some serious megascale engineering becomes
possible.<br>
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<pre class="moz-signature" cols="72">--
Dr Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University</pre>
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