On Wed, Jun 24, 2015 at 05:00:31AM -0400, Richard Aiken wrote:
> Absent developments like that, a fusion-powered energy weapon is
> simply going to vaporize any reasonable opponent fairly quickly,
> with very little muss or fuss.

That's not a given at all.  For any given weapons there is always
going to be a range beyond which it does not automatically hit and
kill, and space combat is most likely to take place outside that
range.  The greater the technology, the more distant that range will
be, and the timescales for changing that range will be correspondingly
longer.

The reason is simple: a combatant who fires from well beyond the
certain-kill range gives up essentially nothing for a *chance* of
killing their opponent.  So almost all of the weapon fire early in an
engagement is going to miss or be otherwise ineffective until the
distance is closed, and closing that distance is going to take a great
deal longer than a second without some sort of magic telportation.

This argument does make some assumptions of course, notably that the
combatants usually aren't already inside each other's certain-death
range when one or both decides they want to kill the other.  (It's
quite plausible in that case that they may both succeed)

- Tim