[time-nuts] Time of death-Again

[jimlux]

jimlux wrote:
> Marshall Eubanks wrote:
>> On Oct 27, 2010, at 6:51 PM, Perry Sandeen wrote:
>>
>>> Gents,
>>>
>>> Wrote: < If you want a sub-microsecond time of death, sit on a bomb 
>>> like Major T. J. "King" Kong in "Dr. Strangelove," and get your 
>>> friends to time and triangulate the prompt radiation. That should be 
>>> good to a few 10's of nanoseconds.
>>>
> 
> 
> Folks, one doesn't need a thermonuclear device for this sort of almost 
> instantaneous disintegration.
> 
> Standard old high explosives could get your "duration of death" down in 
> the submillisecond range, and a simple optical pickup could determine 
> the time when the explosion occurs to nanoseconds (after calibrating for 
> light time delay).
> 
> Black powder which is really a propellant might even be able to 
> disassemble your corpus in less than a millisecond.
> 
> However, if one needs microsecond type uncertainties, then the nuclear 
> device is probably your best bet. Probably not under a microsecond 
> though, from simple mechanical disassembly.  say you were standing just 
> outside the approaching fireball... the fireball (in early stages) grows 
> roughly at the speed of light as the photons proceed out.  The question 
> would be whether there is enough flux to ionize you in a suitably short 
> time.  Basically, you'd have to heat your 100kg or so up to a few 
> thousand K.  Let's see.. 400kJ would heat 100kg up one degree, so 400MJ 
> would get you to 1000 degrees, which is hot, but not ionized.  probably 
> dead though.
> If you were, say, 10 meters away, and your body intercepts 1/2 square 
> meter of the flux which is assumed spread evenly over 314 square meters, 
> the instantaneous power of the explosion would have to be 400MJ*628 in 1 
> microsecond, or about 251GJ/microsecond, or a mere 250E15 Watts
> 


I forgot.. 1 kt (about the smallest practical nuclear device) is about 
4.194 TJ.  Referring to my handy copy of Glasstone, 99.9% of the energy 
is released in about 70 nanoseconds (the last 7 generations), and if 
you're reasonably close, then the energy "pulse" hasn't had much time to 
spread out, so even a small device is well over the threshold to keep 
the variance in your duration of death under a microsecond.