(urth) Hard SF

[Gerry Quinn]

From: Lee Berman


> I think Urth and its dying red sun qualify as hard SF in 
> Antonio's/Asimov's sense
> of being driven by a scientific premise but doesn't qualify as being 
> scientifically
> accurate. Would a sun that drastically diminished really still be able to 
> support tropical
> jungles on Urth? I'd question the liklihood of any major plant growth 
> under those conditions.
>
> I suppose you could make some sort of elaborate argument for how it could 
> happen but I think
> Wolfe's red sun was more of a literary choice than a scienfific one.

Well, it is also a key element of the story.

Personally I would question whether dropping a black hole into the sun would 
dim it.  I think it would cause it to burn hotter, although its life would 
be reduced.  That said, one can imagine mechanisms that would have the 
opposite effect.  Perhaps it generates an accretion disk with causes the 
sun's core to expand and cool.

Basically, most SF involves a lot of hand-waving, probably more than even 
the author knows.  [Otherwise he'd be writing science, after all!]

- Gerry Quinn