nickd
1591
I think...
...it's when the right one is bigger than the left one, but I would have thought you'd know better than me given your anatomy classes 
nick
Greubel Forsey new version of the Quadruple Tourbillon - Baselworld 2009 preview
Press Release Quadruple Tourbillon à Différentiel Sphérique 5N red gold case with lateral window, black dial Quadruple Tourbillon à Différentiel Sphérique Mechanical hand-wound movement, Calibre GF03 Quadruple Tourbillon, seconds indicator and power-reser...
Nearly half the dial
is covered by tourbillon view or air. That's some mighty expensive air-space er......what is a spherical differential for us with under-developed right brains? Regards, MTF
Greubel Forsey are the mad scientists of horology
Regardless of any practical use or scientific evidence on the accuracy of a tourbillon, I really admire these guys for their technical skills. The fact they can build more than one is even more amazing. 1.7g for the cage weight. Talented and crazy. Hope t...
