Isaac Newton

Isaac Newton
Sir Isaac Newton PRSwas an English physicist and mathematicianwho is widely recognised as one of the most influential scientists of all time and a key figure in the scientific revolution. His book Philosophiæ Naturalis Principia Mathematica, first published in 1687, laid the foundations for classical mechanics. Newton made seminal contributions to optics, and he shares credit with Gottfried Wilhelm Leibniz for the development of calculus...
NationalityEnglish
ProfessionScientist
Date of Birth4 January 1643
CityWoolsthorpe, England
If a projectile were deprived of the force of gravity, it would not be deflected toward the earth but would go off in a straight line into the heavens and do so with uniform motion, provided that the resistance of the air were removed.
A cylinder of air reaching to the top of the atmosphere is of equal weight with a cylinder of water about 33 feet high.
[1.] And first I suppose that there is diffused through all places an aethereal substance capable of contraction & dilatation, strongly elastick, & in a word, much like air in all respects, but far more subtile. 2. I suppose this aether pervades all gross bodies, but yet so as to stand rarer in their pores then in free spaces, & so much ye rarer as their pores are less ... 3. I suppose ye rarer aether within bodies & ye denser without them, not to be terminated in a mathematical superficies, but to grow gradually into one another.
He that in ye mine of knowledge deepest diggeth, hath, like every other miner, ye least breathing time, and must sometimes at least come to terr. alt. for air.
Do not several sorts of Rays make Vibrations of several bignesses, which according to their bigness excite Sensations of several Colours, much after the manner that the Vibrations of the Air, according to their several bignesses excite Sensations of several Sounds? And particularly do not the most refrangible Rays excite the shortest Vibrations for making a Sensation of deep violet, the least refrangible the largest form making a Sensation of deep red, and several intermediate sorts of Rays, Vibrations of several intermediate bignesses to make Sensations of several intemediate Colours?
The system of revealed truth which this Book contains is like that of the universe, concealed from common observation yet...the centuries have established its Divine origin.
Every body continues in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it.
If I saw further than other men, it was because I stood on the shoulders of giants.
The word 'God' usually signifies 'Lord', but every lord is not a God. It is the dominion of a spiritual being which constitutes a God: a true, supreme, or imaginary dominion makes a true, supreme, or imaginary God.
The smaller the planets are, they are, other things being equal, of so much the greater density; for so the powers of gravity on their several surfaces come nearer to equality. They are likewise, other things being equal, of the greater density, as they are nearer to the sun.
The same thing is to be understood of all bodies, revolved in any orbits. They all endeavour to recede from the centres of their orbits, and were it not for the opposition of a contrary force which restrains them to and detains them in their orbits, which I therefore call Centripetal, would fly off in right lines with a uniform motion.
The same law takes place in a system, consisting of many bodies, as in one single body, with regard to their persevering in their state of motion or of rest. For the progressive motion, whether of one single body or of a whole system of bodies, is always to be estimated from the motion of the center of gravity.
The hypothesis of matter's being at first evenly spread through the heavens is, in my opinion, inconsistent with the hypothesis of innate gravity without a supernatural power to reconcile them, and therefore, it infers a deity.
The ancients considered mechanics in a twofold respect: as rational, which proceeds accurately by demonstration, and practical. To practical mechanics all the manual arts belong, from which mechanics took its name.