G'morning David, 

 -> And that precludes interaction from within it, `cos for `now' to
 -> stay unchanged nothing could emanate from it - not even one pesky
 -> photon.

 DW> What's "unchanged"? Someone went back to the past and did
something,
 DW> and what exists "now" is, to some extent, influenced by
what he did.
 DW> The non-existent situation is the "now" which *would
have* existed had
 DW> the time-traveller never gone. But that situation is entirely
 DW> imaginary. In reality, he did go, and "now" reflects the effects of
 DW> that. Reality is reality. It isn't changed.

`Reality' as you posit it requires a "now" that contains the 
fruits of all your *future* visits to the past.

For that to be true would require the future to be as fixed as the 
past.

While I'm aware of good evidence that humans don't enjoy the 
freewill they think they have,  your `reality' here would remove 
even the charting of new courses by true random chance....which 
itself would necesarily be illusory.

On the other hand,  given our increasing skills in simulation and 
media,  I can accept that some future enactment of "Macbeth" will 
allow the audience member to move into the action ... and that 
some nth version of "Grand Auto Theft" will provide 2-way 
interaction with that chaotic cast of characters and 
environments....

With the necessary hike in medical insurance premiums, of 
course...

:-)
 
___ MultiMail/MS-DOS v0.45

--- Maximus/2 3.01