A manhole cover exposed to a nearby nuke won't melt entirely (similiar
experiments were made with suspended steel spheres which survived very
nicely), and will certainly experience a stiff acceleration.
In theory, it seems perfectly possible to launch an artillery shell
into space if using a small nuke for a driving charge, but this would
require a very specific geometry (i.e. conical shell and the Big Nuke
Berta) which does not seem to be present in this case.
Robert Harley writes:
> >Surely this ought to be well-documented by now... or is it an urban legend?
>
> A bit of both.
>
> In August 1957, a steel plate was blasted to well over escape velocity
> by a nuclear experiment. Nobody claimed it made it to space, since
> there's that minor matter of the atmosphere.
>
> A few years ago the story appeared in New Scientist (formerly a
> quality magazine, become a vehicle for putting the usual ecologist
> spin on all happenings scientific). The plate had become a manhole
> cover, and needless to say it was launched by accident (those evil
> nuclear scientists are always messing about blowing things up by
> accident you see). According to this version: if it could have made
> it out of the atmosphere it would have escaped from Earth's gravity.
> Well duh. Like what does "escape velocity" mean?
>
> Now the meme seems to have mutated into: it escaped the Earth, the
> Solar System and who knows what else. This strain of the meme will
> probably catch on because Americans would love to believe that they
> actually beat those darn Russkies into space after all.
>
>
> The entire claim seems pretty dubious to me. Most of the explosion's
> energy would be released as radiation which would melt the plate (at
> least) immediately. The shock wave would hit it after a fraction of a
> second and send globs of molten steel flying. There would be no
> intact plate to be "watched leaving the area" on camera.
>
> The speed claim also seems dubious, even applied to globs of molten
> steel. I wonder is it legend too, proceeding from the popular belief
> that nuclear explosions can do just anything because they're
> infinitely powerful. I could be wrong on this though.
>
> In any case, in the atmosphere the globs would be broken down into
> ever smaller drops with ever larger surface area per unit momentum,
> getting heated up and slowed down immensely for a second or more
> (that's a hell of a long time!)
>
> That thing came down in a fine rain of liquid steel spread all over
> the Nevada desert, if you ask me.
>
>
> Rob.