(urth) Terminus Est

[John Smith]

Gwern has a clever suggestion about the mercury
channel in Terminus Est:

 "Well, why do we need a vacuum at all,
 when we could just have air in it like normal and
avoid displacement
 problems by making our channel a circular tube."

This is a good idea, but I don't think it would work. 
 When you raise the sword, the mercury would pool at
the bottom in both channels.  Then on the downstroke,
the mercury would flow down both channels, resulting
in the same air compression problem.   We might want
the mercury to flow down one channel and the air to
flow up the other, but mercury will simply follow the
laws of physics.

The text also indicates a single channel:   
"There is a channel in the spine of her blade, and in
it runs a river of hydragyrum"  (Shadow, XIV).

Best wishes,

Jack

Best wishes,

Jack