Re: Return to No Stealth in Space

On 7 apr, 10:22, Eivind Kjorstad <eivindor...@[EMAIL PROTECTED]
> wrote:
> Crown-Horned Snorkack skreiv:
>
> > 1x solar luminosity is 0,14 watts per square cm. 10x solar luminosity
> > is 1,4 watts per square cm.
>
> > Table 4-VI. Consider a 10 MT air burst at the range of 14,5 km. This
> > can cause second degree burns on exposed skin by delivering a total of
> > 29,3 joules per square cm. Which is equivalent to the ac***ulated
> > sunlight of 210 s.
>
> 210 seconds of sunlight delivered in how long ? For 10-times-sunlight
> that would be delivered in 21 seconds, but as you yourself say, the
> energy is delivered substantially faster than that.
>
> > 70 % of the thermal energy is delivered over 12 s -
> > which means it is about 12 times the luminosity of Sun averaged over
> > 12 s.
>
> Yes. And even within those 12 seconds it's unlikely to be a flat curve,
> rather there's going to be a peak at atleast 100 times solar, perhaps
more.
>
> > 2nd degree flash burns over exposed skin are commonly fatal...
>
> True. But you're moving the goalposts.
>
> There's a difference between "commonly fatal" and "will kill everyone".
> The original statement was that "everyone dies" in "less than an hour".
>
> A substantial fraction of humanity is going to be indoor at any given
> moment, some are even going to be sub-terrain or sub-water.
>
> Nobody disputes that increasing the heat-input to a continent to say 10
> times solar over a period of an hour would kill many people, perhaps
> most people.
>
> I don't see any reason to believe it'd kill -everyone- though, not even
> close.
>
True.

10 times solar luminosity for 20 seconds is likely fatal for many
people who are outside with bare skin, through flash burns.

10x solar luminosity for prolonged time should by Stefan-Boltzmann law
eventually heat ambient air to 250-300 Celsius. Which is not
survivable in longer term: in baths, people put up with 100...150
Celsius dry air easily, but 200+ is another matter.

However, in short term (minutes, hours)...

As for people indoors, buildings can be set on fire.

If they do not catch fire from direct radiant heat, the cool air would
drain out and the rooms fill with 200+ degree air.

However, chilly air would remain stagnant in cellars and tunnels where
it has nowhere to drain. For how long?