[time-nuts] I think I've become a Volt nut too.

[Magnus Danielson]

Bob Camp wrote:
> Hi
> 
> For open box pendulums, the air swishing around in the cave should be very effective at locking every single one of them up. 
> 
> For something like a vacuum enclosed clock you would need lock modes that are a bit more crazy.

Vacuum enclosure still allows acoustical coupling through the support 
mechanics. Consider a speaker element, it pushes a bit of air away along 
with push its cone in that direction. However, the force has a counter 
fource to the underlying ground. While the movement is smaller, due to 
its higher acoustical impedance, it is still there. Similar for a 
pendulum, as it swings, the support mecanics feels a shift in force with 
the rate of the swing, so counter-acting force is need for not moving 
around. Maybe the best illustration would be the placement of a pendulum 
on top of a piece of ice over wet ice.

So, by saying acoustical, I by no means imply the waves in air.

Cheers,
Magnus