[p00b]

Very cool experiment, and even cooler visual results!

One thing though - the tilting of the scene from the phone's perceived variance of the gravity vector is not due to centrifugal force, but due to inertia.

In other words, it's the same reason you're pushed back into your seat when you accelerate, and slam your head into the dashboard and spill hot coffee in your lap when you lock up the breaks.

[petrakeas]

We also did an experiment with this: http://imgur.com/tdnympM

The same problem existed. So it is not inertia in this case. However, inertia could also interfere with the gravity vector.