On 14 Jan 2015 at 18:54, Anthony Jackson wrote:

> From: David Shaw
> >
> > I have never attempted relativistic calculations before and wondered if
> > I have this right.
> >
> > I am currently reading John Ringo's 'Gust Front' in which a ground
> > based anti-starship weapon is described as firing bars of depleted
> > uranium, 100mm in diameter and two metres long at a muzzle velocity of
> > 0.3c.
> >
> > I make this a KE of 1.302 exa-Joules, equivalent to a touch over 311MT
> > of TNT.  Is this right?  And would such a weapon system really be
> > feasible within an Earth-standard atmosphere?
>
> It's John Ringo. *Never* do the math. In any case, no, it won't work, I'm not sure if it will even escape the atmosphere, but even if it does, it will do so as a rapidly expanding cone, not a solid projectile.

I don't know about *that* particular weapon, but I was around on
rec.arts.sf.science many years ago when this guy named Ringo was
asking for help with ideas.

I was one of the folks back then who sanity checked some of the guy's
ideas.

Years later after I posted on Baen's Bar about something I got a
private email asking if I was the same Leonard Erickson and thinking
me for help.

Yerah, I hadn't realized that the books were using the info from
those long ago discussions.

But as I said, I know that a lot of tyhe stuff *was* sanity checked.

Of course, after we tore apart his original ideas and suggested more
workable alteratives, I don't know how much checking he had doe for
the later books.

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com