Law Of Gravitation Quotes (3)
Newton supposed that the case of the planet was similar to that of [a ball spun around on the end of an elastic string]; that it was always pulled in the direction of the sun, and that this attraction or pulling of the sun produced the revolution of the planet, in the same way that the traction or pulling of the elastic string produces the revolution of the ball. What there is between the sun and the planet that makes each of them pull the other, Newton did not know; nobody knows to this day; and all we are now able to assert positively is that the known motion of the planet is precisely what would be produced if it were fastened to the sun by an elastic string, having a certain law of elasticity. Now observe the nature of this discovery, the greatest in its consequences that has ever yet been made in physical science:—
I. It begins with an hypothesis, by supposing that there is an analogy between the motion of a planet and the motion of a ball at the end of a string.
II. Science becomes independent of the hypothesis, for we merely use it to investigate the properties of the motion, and do not trouble ourselves further about the cause of it.
I. It begins with an hypothesis, by supposing that there is an analogy between the motion of a planet and the motion of a ball at the end of a string.
II. Science becomes independent of the hypothesis, for we merely use it to investigate the properties of the motion, and do not trouble ourselves further about the cause of it.
'On Some of the Conditions of Mental Development,' a discourse delivered at the Royal Institution, 6 Mar 1868, in Leslie Stephen and Frederick Pollock (eds.), Lectures and Essays, by the Late William Kingdon Clifford (1886), 56.
Oh! That the Chemist's magic art
Could crystallize this sacred treasure!...
That very law which moulds a tear,
And bids it trickle from its source;
That law preserves the earth a sphere,
And guides the planets in their course.
Could crystallize this sacred treasure!...
That very law which moulds a tear,
And bids it trickle from its source;
That law preserves the earth a sphere,
And guides the planets in their course.
&$039;On a Tear', in Samuel Rogers et al., The Poetical Works of Rogers, Campbell, J. Montombery, Lamb, and Kirke White (1836), 101.
See also: | Chemist (20) | Guide (3) | Law (134) | Magic (8) | Mould (5) | Orbit (16) | Planet (34) | Sphere (5) | Tear (3) | Treasure (5)
… for it is very probable, that the motion of gravity worketh weakly, both far from the earth, and also within the earth: the former because the appetite of union of dense bodies with the earth, in respect of the distance, is more dull: the latter, because the body hath in part attained its nature when it is some depth in the earth.
[Foreshadowing Newton's Universal Law of Gravitation (1687)]
[Foreshadowing Newton's Universal Law of Gravitation (1687)]
Sylva Sylvarum; or a Natural History in Ten Centuries (1627), Century 1, Experiment 33. Collected in The Works of Francis Bacon (1826), Vol 1, 255.
See also: | Sir Isaac Newton (82)
