  Isaac Newton is usually associated with the idea of absolute space and time,
and with ballistic light-corpuscle arguments. However, Newton was also a
proponent of wave/particle duality, and published a "new" variable-density
aether model in which light and matter trajectories were either bent by
gravitational fields, or deflected by an aether density gradient. Newton's
(flawed) aether model can be considered as an early attempt at a curved-space
model of gravity.
