Static Pressure
Newton updated the second edition of Optics (1717) with another mechanical-ether theory of gravity. Unlike his first explanation (1675 - see Streams), he proposed a stationary aether which gets thinner and thinner nearby the celestial bodies. On the analogy of the lift (force), a force arises, which pushes all bodies to the central mass. He minimized drag by stating an extremely low density of the gravitational aether.
Like Newton, Leonhard Euler presupposed in 1760 that the gravitational aether loses density in accordance with the inverse square law. Similarly to others, Euler also assumed that to maintain mass proportionality, matter consists mostly of empty space.
Criticism: Both Newton and Euler gave no reason why the density of that static aether should change. Furthermore, James Clerk Maxwell pointed out that in this "hydrostatic" model "the state of stress... which we must suppose to exist in the invisible medium, is 3000 times greater than that which the strongest steel could support".
Read more about this topic: Mechanical Explanations Of Gravitation
Famous quotes containing the word pressure:
“Adolescence is when girls experience social pressure to put aside their authentic selves and to display only a small portion of their gifts.”
—Mary Pipher (20th century)