Top 247 Quotes & Sayings by Isaac Newton - Page 4

From what has been said it is also evident, that the Whiteness of the Sun's Light is compounded all the Colours wherewith the several sorts of Rays whereof that Light consists, when by their several Refrangibilities they are separated from one another, do tinge Paper or any other white Body whereon they fall. For those Colours ... are unchangeable, and whenever all those Rays with those their Colours are mix'd again, they reproduce the same white Light as before.

Do not great Bodies conserve their heat the longest, their parts heating one another, and may not great dense and fix'd Bodies, when heated beyond a certain degree, emit Light so copiously, as by the Emission and Re-action of its Light, and the Reflexions and Refractions of its Rays within its Pores to grow still hotter, till it comes to a certain period of heat, such as is that of the Sun?

His epitaph: Who, by vigor of mind almost divine, the motions and figures of the planets, the paths of comets, and the tides of the seas first demonstrated.

The Synthesis consists in assuming the Causes discovered and established as Principles, and by them explaining the Phænomena proceeding from them, and proving the Explanations.

I do not define time, space, place, and motion, as being well known to all. Only I must observe, that the common people conceive those quantities under no other notions but from the relation they bear to sensible objects. And thence arise certain prejudices, for the removing of which it will be convenient to distinguish them into absolute and relative, true and apparent, mathematical and common.

Thus this Earth resembles a great animall or rather an inanimate vegetable, draws in aethereal breath for its dayly refreshment and vitall ferment and transpires again grosses exhalations. And, according to the condition of all other things living, ought to have its time of beginning, youth, old age and perishing.

How came the bodies of animals to be contrived with so much art, and for what ends were their several parts? Was the eye contrived without skill in Opticks, and the ear without knowledge of sounds?...and these things being rightly dispatch’d, does it not appear from phænomena that there is a Being incorporeal, living, intelligent...?

When the adversaries of Erasmus had got the Trinity into his edition, they threw by their manuscript as an old almanac out of date.

Because of Diamond, I have had to begin much of the work afresh. I will not, however, rid myself of her, nor even punish her. She knew not what she was doing, and that which she did was for my protection and for love of my person. Her place remains at my side or against my feet when I lie abed.

A Vulgar Mechanick can practice what he has been taught or seen done, but if he is in an error he knows not how to find it out and correct it, and if you put him out of his road he is at a stand. Whereas he that is able to reason nimbly and judiciously about figure, force, and motion, is never at rest till he gets over every rub. (from a letter dated 25 May, 1694)

The best and safest way of philosophising seems to be, first to enquire diligently into the properties of things, and to establish those properties by experiences [experiments] and then to proceed slowly to hypotheses for the explanation of them. For hypotheses should be employed only in explaining the properties of things, but not assumed in determining them; unless so far as they may furnish experiments.

This Excellent Mathematician having given us, in the Transactions of February last, an account of the cause, which induced him to think upon Reflecting Telescopes, instead of Refracting ones, hath thereupon presented the curious world with an Essay of what may be performed by such Telescopes; by which it is found, that Telescopical Tubes may be considerably shortened without prejudice to their magnifiying effect. On his invention of the catadioptrical telescope, as he communicated to the Royal Society.

Our design, not respecting arts, but philosophy, and our subject, not manual, but natural powers, we consider chiefly those things which relate to gravity, levity, elastic force, the resistance of fluids, and the like forces, whether attractive or impulsive; and therefore we offer this work as mathematical principles of philosophy; for all the difficulty of philosophy seems to consist in this from the phenomena of motions to investigate the forces of nature, and then from these forces to demonstrate the other phenomena.

Bullialdus wrote that all force respecting ye Sun as its center & depending on matter must be reciprocally in a duplicate ratio of ye distance from ye center.

As I am writing, another illustration of ye generation of hills proposed above comes into my mind. Milk is as uniform a liquor as ye chaos was. If beer be poured into it & ye mixture let stand till it be dry, the surface of ye curdled substance will appear as rugged & mountanous as the Earth in any place.

This principle of nature being very remote from the conceptions of Philosophers, I forbore to describe it in that book, least I should be accounted an extravagant freak and so prejudice my Readers against all those things which were the main designe of the book.

I have presented principles of philosophy that are not, however, philosophical but strictly mathematical-that is, those on which the study of philosophy can be based. These principles are the laws and conditions of motions and of forces, which especially relate to philosophy.

The monarchy of the Greeks for want of an heir was broken into several kingdoms; four of which, seated to the four winds of heaven, were very eminent. For Ptolemy reigned over Egypt, Lybia and Ethiopia ; Antigonus over Syria and the lesser Asia; Lysimachus over Thrace ; and Cassander over Macedon, Greece and Epirus .

Now the smallest Particles of Matter may cohere by the strongest Attractions, and compose bigger Particles of weaker Virture.... There are therefore Agents in Nature able to make the Particles of Bodies stick together by very strong Attraction. And it is the Business of experimental Philosophy to find them out.

If the ancient churches, in debating and deciding the greatest mysteries of religion, knew nothing of these two texts, I understand not why we should be so fond of them now the debate is over.

I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses; for whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.

You sometimes speak of gravity as essential and inherent to matter. Pray do not ascribe that notion to me, for the cause of gravity is what I do not pretend to know, and therefore would take more time to consider of it.

By such deductions the law of gravitation is rendered probable, that every particle attracts every other particle with a force which varies inversely as the square of the distance. The law thus suggested is assumed to be universally true.

Absolute, true and mathematical time, of itself, and from its own nature flows equably without relation to anything external.

Do not Bodies act upon Light at a distance, and by their action bend its Rays; and is not this action (caeteris paribus) [all else being equal] strongest at the least distance?

To any action there is always an opposite and equal reaction; in other words, the actions of two bodies upon each other are always equal and always opposite in direction.

Doth not this Æthereal Medium in passing out of Water, Glass, Crystal, and other compact and dense Bodies into empty Spaces, grow denser and denser by degrees, and by that means refract the Rays of Light not in a point, but by bending them gradually in curve Lines? And doth not the gradual condensation of this Medium extend to some distance from the Bodies, and thereby cause the Inflexions of the Rays of Light, which pass by the edges of dense Bodies, at some distance from the Bodies?

What the Latins have done in this text (1 John v, 7) the Greeks have done to Paul (1 Tim. iii, 16). They now read, "Great is the mystery of godliness; God manifest in the flesh"; whereas all the churches for the first four or five hundred years, and the authors of all the ancient versions, Jerome as well as the rest, read, "Great is the mystery of godliness, which was manifest in the flesh." Our English version makes it yet a little stronger. It reads, "Great is the mystery of godliness: God was manifest in the flesh."

Are not all Hypotheses erroneous, in which Light is supposed to consist in Pression or Motion, propagated through a fluid Medium? For in all these Hypotheses the Phaenomena of Light have been hitherto explain'd by supposing that they arise from new Modifications of the Rays; which is an erroneous Supposition.

Philosophy is such an impertinently litigious lady that a man had as good be engaged in lawsuits as have to do with her.

Qu. 31. Have not the small Particles of Bodies certain Powers, Virtues or Forces, by which they act at a distance, not only upon the Rays of Light for reflecting, refracting and reflecting them, but also upon one another for producing a great part of the Phænomena of Nature?

For the Rays, to speak properly, have no Colour. In them there is nothing else than a certain power and disposition to stir up a sensation of this Colour or that.

I see I have made myself a slave to Philosophy, but if I get free of Mr. Linus's business I will resolutely bid adew to it eternally, excepting for what I do for my private satisfaction or leave to come out after me. For I see a man must either resolve to put out nothing new or to become a slave to defend it.

In scripture we are told of some trusting in God and others trusting in idols, and that God is our refuge, our strength, our defense. In this sense God is the rock of his people, and false Gods are called the rock of those that trust in them. In the same sense the Gods of the King who shall do according to his will are called Mahuzzims, munitions, fortresses, protectors, guardians, or defenders.

Thus far I have explained the phenomena of the heavens and of our sea by the force of gravity, but I have not yet assigned a cause to gravity. Indeed, this force arises from some cause that penetrates as far as the centers of the sun and planets without any diminution of its power to act, and that acts not in proportion to the quantity of the surfaces of the particles on which it acts (as mechanical causes are wont to do) but in proportion to the quantity of solid matter, and whose action is extended everywhere to immense distances, always decreasing as the squares of the distances.

Therefore, the causes assigned to natural effects of the same kind must be, so far as possible, the same.

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.

My Design in this Book is not to explain the Properties of Light by Hypotheses, but to propose and prove them by Reason and Experiments: In order to which, I shall premise the following Definitions and Axioms.

I have been much amused at ye singular phenomena resulting from bringing of a needle into contact with a piece of amber or resin fricated on silke clothe. Ye flame putteth me in mind of sheet lightning on a small-how very small-scale.

Against filling the Heavens with fluid Mediums, unless they be exceeding rare, a great Objection arises from the regular and very lasting Motions of the Planets and Comets in all manner of Courses through the Heavens.

Thus you may multiply each stone 4 times & no more for they will then become oyles shining in ye dark and fit for magicall uses. You may ferment them with gold and silver, by keeping the stone and metal in fusion together for a day, & then project upon metalls. This is the multiplication of ye stone in vertue. To multiply it in weight ad to it of ye first Gold whether philosophic or vulgar.

Our present work sets forth mathematical principles of philosophy. For the basic problem of philosophy seems to be to discover the forces of nature from the phenomena of motions and then to demonstrate the other phenomena from these forces. It is to these ends that the general propositions in books 1 and 2 are directed, while in book 3 our explanation of the system of the world illustrates these propositions.

'Tis the temper of the hot and superstitious part of mankind in matters of religion ever to be fond of mysteries, and for that reason to like best what they understand least.

The alternation of motion is ever proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed.

As in Mathematicks, so in Natural Philosophy, the Investigation of difficult Things by the Method of Analysis, ought ever to precede the Method of Composition. This Analysis consists in making Experiments and Observations, and in drawing general Conclusions from them by Induction, and admitting of no Objections against the Conclusions, but such as are taken from Experiments, or other certain Truths. For Hypotheses are not to be regarded in experimental Philosophy.

A good watch may serve to keep a recconing at Sea for some days and to know the time of a Celestial Observ[at]ion: and for this end a good Jewel watch may suffice till a better sort of Watch can be found out. But when the Longitude at sea is once lost, it cannot be found again by any watch.

The kingdoms represented by the second and third Beasts, or the Bear and Leopard, are again described by Daniel in his last Prophecy written in the third year of Cyrus over Babylon , the year in which he conquered Persia. For this Prophecy is a commentary upon the Vision of the Ram and He-Goat.

In experimental philosophy, propositions gathered from phenomena by induction should be considered either exactly or very nearly true notwithstanding any contrary hypotheses, until yet other phenomena make such propositions either more exact or liable to exceptions.

Pontus, instituted among all people, as an addition or corollary of devotion towards God, that festival days and assemblies should be celebrated to them who had contended for the faith (that is, to lie martyrs ).

All material Things seem to have been composed of the hard and solid Particles ... variously associated with the first Creation by the Counsel of an intelligent Agent. For it became him who created them to set them in order: and if he did so, it is unphilosophical to seek for any other Origin of the World, or to pretend that it might arise out of a Chaos by the mere Laws of Nature.

Centripetal force is the force by which bodies are drawn from all sides, are impelled, or in any way tend, toward some point as to a center.

No old Men (excepting Dr. Wallis) love Mathematicks.

Do not the Rays of Light which fall upon Bodies, and are reflected or refracted, begin to bend before they arrive at the Bodies; and are they not reflected, refracted, and inflected, by one and the same Principle, acting variously in various Circumstances?

A cylinder of air reaching to the top of the atmosphere is of equal weight with a cylinder of water about 33 feet high.

Oh Diamond! Diamond! thou little knowest the mischief done! [Apocryphal]

Henceforward the Christian Churches having a form of godliness, but denying the power thereof, came into the hands of the Encratites: and the Heathens, who in the fourth century came over in great numbers to the Christians, embraced more readily this sort of Christianity, as having a greater affinity with their old superstitions, than that of the sincere Christians; who by the lamps of the seven Churches of Asia, and not by the lamps of the Monasteries, had illuminated the Church Catholic during the three first centuries.

[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.

It is indeed a matter of great difficulty to discover, and effectually to distinguish, the true motions of particular bodies from the apparent; because the parts of that immovable space, in which those motions are performed, do by no means come under the observation of our senses. Yet the thing is not altogether desperate; for we have some arguments to guide us, partly from the apparent motions, which are the differences of the true motions; partly from the forces, which are the causes and effects of the true motions.

Do not Bodies and Light act mutually upon one another; that is to say, Bodies upon Light in emitting, reflecting, refracting and inflecting it, and Light upon Bodies for heating them, and putting their parts into a vibrating motion wherein heat consists?

The main Business of Natural Philosophy is to argue from Phænomena without feigning Hypotheses, and to deduce Causes from Effects till we come to the very first Cause, which certainly is not mechanical; and not only to unfold the Mechanism of the World, but chiefly to resolve these, and to such like Questions.