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On 2015-09-08 00:32, Adrian Tymes wrote:<br>
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cite="mid:CALAdGNQQ6iXU_epaOX0pRxMQAFFJkb0QxPAO00=UJgbzJxKpxg@mail.gmail.com"
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<div class="gmail_quote">On Mon, Sep 7, 2015 at 4:24 PM,
Anders Sandberg <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:anders@aleph.se"
target="_blank">anders@aleph.se</a>></span> wrote:<br>
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<div bgcolor="#FFFFFF" text="#000000"> You cannot just set
fire to the whole world.<br>
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<div>Actually, there's been quite a bit of thought on ways
to do just that. Look up "atmospheric ignition". If you
put enough methane or grain dust out there, for instance,
it might be possible.<br>
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<br>
For what values of practical? Nukes will not do it, as a certain
famous report pointed out. <br>
<br>
The LFL for methane is 4% volume, so you need to add about <span
class="cwcot" id="cwos">1.35e17</span> kg of methane to ignite it.
This is about 2-3 times the total carbon stored in the oceans and
several times the carbon content of the biosphere. Grain dust is
even less effective, since we are talking about a LFL larger than 2
kg/m^3 -this is way bigger.<br>
<br>
<br>
("Anders, what are you doing?"<br>
"Calculating how to set the atmosphere on fire. There has to be a
better way... maybe hydrogen?"<br>
"Remember, we are supposed to *save* the world at this institute."<br>
"Yes, boss.")<br>
<br>
<pre class="moz-signature" cols="72">--
Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University</pre>
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