[RascalPuff]

The 'Gravitational Alternative', offered by Sir Isaac Newton.


(Here, Newton allows that gravity may act in the opposite direction from a pulling force - that it may be a pushing force. This is over 230 years before Einstein proclaimed that gravity is indeed a repelling - pushing force - via the General Principle of Relativity.)


Principia Mathematica, preface, p.p. 2 and 3 - excerpt, verbatim (from the 3 page preface to the Principia):


"I wish we could derive the rest of the phenomena of nature by the same kind of reasoning by mechanical principles; for I am induced by many reasons to suspect that they may all depend upon certain forces by which the particles of bodies, by some causes hitherto unknown, are either mutually impelled towards each other, and cohere in regular figures, or, are repelled and recede from each other; which forces, being unknown, philosophers have hitherto attempted the search of nature in vain; but I hope the principles here laid down will afford some light either in that or some truer method of philosophy." - Sir Isaac Newton, 1686