--- Alan Kay <Alan.Kay at squeakland.org> wrote:
> In hardware, an inverter that sends a message back
> to its input 
> becomes a clock (this is because there is a delay).
> Two of these can 
> be made into a flip-flop which is a more interesting
> delay. Etc.

It's a semaphore, for one thing.  Perhaps the use of
Special relativity has to do with how fast a context
switch between processes can occur. 

Sorry for shouting and blabbering, earlier.  I got a
little jumpy,
Rob