Re: My basic understanding of G-forces.
I think the most predominant variable here is the hardness of the material that the watch hits, and it also has a fair amount to do with the angle that it hits at. A strike at a low angle of attack will have a much lower G-force associated with it that a direct 90 degree strike. That by itself pretty much takes the subject of falling off your bike onto concrete out of something that could be estimated.
As far as distance, a standard distance like one meter is generally used because if you drop something, that's about how far it will fall before it hits the ground.
The hardness of the surface that the watch hits is the major variable, and the primary reason for this is that the G force is calculated by a time over distance deceleration rate. As three examples, take wood, concrete, and titanium carbide, which is pretty close to diamond in hardness. If you were to do a face plant on any of the three off your bicycle, there wouldn't be much difference, because all of the deceleration is coming from YOUR BODY and NOT the hard surface.
Assume, however, that a watch hitting wood will stop after traveling into the wood .01", .001" for concrete, and .0001" for titanium carbide. Seeing as the watch was traveling at an equivalent velocity in all three cases, The G force for the concrete is going to be 10 times higher than the wood and the TiC is going to be 100 times higher. The real variable here that is changing is the TIME variable, and because TiC is so incredibly hard the total deceleration time is measured in microseconds instead of milliseconds. G load is a statement of acceleration over time, and when you shrink the time variable down to practically zero, the G value goes expotential.
In reality, the g load on your watch while it's ON you is really not an independent variable, because the biggest "squish" factor is YOU and not the watch. The area that truly raises concern are things like ceramic tile, (meaning aluminum oxide, which is slightly softer than TiC, but not much...) which you normally find in bathrooms and showers. Drop a watch on that, and the G force is WAAYYY up there. Much worse than wood or Corian, which as John knows is partially a polymer structure, and therefore not nearly as hard as tile.
This is why it's SUCH a bad idea to take your Seamaster off your wrist before you shower, because if you have a ceramic tile floor you're in a maximum g-force deceleration zone.
