From: owner-cypherpunks@toad.com
Date: Thu, 22 Feb 1996 18:58:28 +0800
Subject: No Subject
Message-ID: <QQadzv26493.199602221052@relay3.UU.NET>
MIME-Version: 1.0
Content-Type: text/plain


At 10:56 PM 2/21/96 -0500, Black Unicorn wrote:
>On Sun, 18 Feb 1996, jim bell wrote:
>
>> -----BEGIN PGP SIGNED MESSAGE-----
>> 
>> At 10:25 PM 2/18/96 EDT, E. ALLEN SMITH wrote:
>> >	I've been kind of busy recently (the reason I haven't responded to
>> >the more recent Assasination Politics stuff), but I'm curious what 
>> >your method is for achieving simultaneous explosions.
>> 
>> 
>> "Multiple very thin flexible hollow tubes (1 mm ID? teflon?) filled with a
>> homogenous liquid 
>> explosive (for example, pure nitromethane), length accurately cut to produce 
>> the exactly desired delay.  Kept separated from each other by foam spacers 
>> to avoid inter-fiber detonations. Detonated from a single cap, with an 
>> intermediary chamber of liquid explosive to stabilize the shock front, the 
>> detonation wave travels along each tube simultaneously at (presumably) 
>> identical velocity."
>
>This method is so dependent on the uniformity of the initiator (the cap 
>in this instance) as to be nearly useless.  Normal blasting caps do not 
>detonate with the uniformity required to initiate each of the tube paths 
>at the same time.  In the off chance that you contemplated surrounding 
>the cap with liquid explosive of a sufficent type, (which still wouldn't 
>assure proper uniformity with any certainty as the liquid explosive is as 
>likely to detonate slightly off left to right as up to down) you still have 
>extremely difficult problems to overcome.

Re-read my whole statement.  I copy the relevant commentary that you
sloppily forgot to read:

>> Detonated from a single cap, with an 
>> intermediary chamber of liquid explosive to stabilize the shock front,

I already entirely anticipated your objection.  And destroyed it.

>1>  Interference from the milling shape and accuracy of the openings to 
>the tubes containing the liquid explosive.

Quantify, quantify.  How much of a problem?  (Hint:  If you seriously 
believed there was a problem with this idea, you would be able to give a few 
examples on how to avoid them.  Reading your commentary, you did none of 
this.  

>2>  Mild to obscure impurities in the liquid explosives causing 
>differences in velocity with respect to other tubes. 

All the tubes can be filled at the last minute by pulling a vacuum on the
system and letting atmospheric pressure fill all the tubes.  No impurities,
or at least it's a perfectly homogeneous mixture.

> Even small changes 
>in pressures within the tubes might cause enough timing problems to make 
>uniform initiation of the primary high explosive assembly impossible.

"might"?  Well, could you be more specific?  How many nanoseconds would be
too many?


>3>  Interference from the milling shape and accuracy of the terminus of 
>the tubes containing the liquid explosive.

So what's your point?

>4>  Overpressure in the device causing premature detonation of the near 
>portion of the high explosive assembly.

Sure about that?

>All of these might cause enough timing error to prevent uniform pressure 
>and thus prevent uniform compression and make supercriticality impossible.

Pigs might fly.

>Remember, kryonic switiches are necessary even when dealing with the 
>speeds of electric conductivity.  The velocities of even hydrazine based 
>explosives are signigicantly lower.  The margin for error is similarly lower.

How low?  Be specific.

>Plutonium gun is still the easiest method for the home grown nuclear 
>device, even if it requires more fissile material.

The "gun" design wasn't used with the plutonium, because IT WOULD NOT HAVE 
WORKED! "Fat Man," the bomb dropped on Nagasaki, used the implosion method.  
"Little Boy," the gun-method bomb, used U-235.   Plutonium detonates far too 
rapidly to use the "gun" method.   The 
scientists knew that in 1945.  You seem to be at least 50 years behind the 
times.

Sheesh!  I guess we now know what field YOU don't know about, huh?  Or, 
perhaps more likely, this is a specific DIS-information campaign.   You want 
someone to waste a critical-mass worth of plutonium.