[ExI] anders' sea of pu, was: RE: The Pace of Technology Adoption is Speeding Up

[spike]

>... On Behalf Of BillK
Subject: Re: [ExI] The Pace of Technology Adoption is Speeding Up

On Mon, Dec 2, 2013 at 3:29 PM, spike  wrote:
>>... Thanks Anders, this is the best short commentary that sums up why I 
> have eschewed Facebook and texting.  Neither of those media are 
> conducive to the kinds of processes going on in my head, even if they have
their uses.


>...Yes, you certainly don't want to frighten those of a nervous disposition
by displaying the kinds of processes going on in your head!  :)

>...Even strong men quail and tremble at the suggestion.

>...BillK
_______________________________________________

BillK you flatter me sir, thanks.  {8-]  

I do have some fun stuff going on in here currently.  For this I am indebted
to Dr. Sandberg, for his comment last week about seas of plutonium gave me
an idea.  Suppose you are God {it has to be the capital G for this task, Mr.
Damn himself, and even God in all his omnipotence might not have sufficient
Om.}  Make an earth-mass sphere of pure 244 plutonium as cold as you can
make it, 0 K.  How long before we can start swimming?

Taking just the first decay, alpha-ing down from 244Pu to neptunium 240, the
half-life is about 80 million years and the alpha pings off at an energy of
about 4.7MeV and the heat cap of plutonium is about 35 J*mol-1*K-1, so

(6E23 atoms*mol-1)*(ln(2))/(2.4e15sec){half-life of
244Pu}*(4.7Mev/decay)*(1Joule/(6.2E12MeV))*(mol*K/35J)

= 3.7E-6 K/sec, so the plutonium planet {hmmmm, a plutonium planet, what
could we call it, hmmmm...) would go from absolute zero to a nice warm swim
in molten plutonium in a little less than 8 years.

But wait, there's more.  Less actually, for the daughters of Pu244 are an
alpha and uranium 240, but 240U has a half-life of only 14 hours and the
resulting 240Np has a half-life of only about an hour, so you quickly double
beta back to plutonium 240.  This is a clean decay chain because there is no
neutron capture available in this artificial environment; only alphas and
Pu244 about, so after a very short time, we have these 240Pu atoms, which
have a half-life of about 6600 years, with an even higher energy alpha
pinging off at about 5.3Mev.  But since there isn't much of that, you can
neglect it for this calculation, and look at just the energy released in the
double beta decay of Neptunium to get from a frozen ball of 244Pu to a
molten sea in about 5 years, but somewhere in this discussion, I should
offer a polite greeting to the local NSA agent who is wondering why I am
googling about the internets wanting to learn about half-ife of plutonium,
uranium and neptunium, so hello there Ms. or Mr. NSA agent!

In any case, the amount of 240Pu is increasing, so the heating rate starts
at about 4 microKelvin per second and accelerates.  It's a fun exercise to
think about what happens as the whole shebang heats up and starts
self-heating ever faster as you increase the amount of more fizzile
daughters, and yes I intentionally misspelled fizzile, for I only wish to
greet the NSA agents, not tease them.

Ja BillK, it is fun in here, and ja it isn't the place to bring your
grandmother or small children.  Even if grandma is single and attractive,
I'm not.  {8^D

{8-]

spike