Matter and Motion Quotes

“The first part of physical science relates to the relative position and motion of bodies.”

“In future... when we use the word acceleration without qualification, we mean... the rate of acceleration.”

“Relative, apparent, and common time is duration as estimated by the motion of bodies, as by days months and years.”

“Acceleration, like position and velocity, is a relative term and cannot be interpreted absolutely.”

“The model or diagram is supposed to resemble the material system only in form, not necessarily in any other respect.”

“I would advise those who study any system of metaphysics to examine carefully that part of it which deals with physical ideas.”

“The idea of Time in its most primitive form is probably the recognition of an order of sequence in our states of consciousness.”

“The word Acceleration is here used to denote any change in the velocity, whether that change be an increase, a diminution, or a change of direction.”

“The total effect of a force in communicating velocity to a body is therefore proportional to the force and to the time during which it acts conjointly.”

“The motion of a material particle which has continuous existence in time and space is the type and exemplar of every form of continuity.”

“We cannot... regard Newton's statement as an appeal to experience and observation, but rather as a deduction of the third law of motion from the first.”

“The effect of a given force on a body does not depend on the motion of that body. Neither is it affected by the simultaneous action of other forces on the body.”

“A knowledge of the configuration of the system at a given instant implies a knowledge of the position of every point of the system with respect to every other point at that instant.”

“It may thus be shown that the denial of Newton's [first] law is in contradiction to the only system of consistent doctrine about space and time which the human mind has been able to form.”

“Absolute, true, and mathematical Time is conceived by Newton as flowing at a constant rate, unaffected by the speed or slowness of the motions of material things. It is also called duration.”

“To prove the laws of motion by the law of gravitation would be an inversion of scientific order. We might as well prove the law of addition of numbers by the differential calculus.”

“Statement of the Second Law of Motion in Terms of Impulse and Momentum—The change of momentum of a body is numerically equal to the impulse which produces it and is in the same direction.”

“The total acceleration in a given time is proportional to the force. For if several equal forces act in the same direction on the same body in the same direction, each produces its effect independently of the others.”

“The momentum of any body is... measured in terms of the momentum of unit of mass moving with unit of velocity which is taken as the unit of momentum.”

“We arrive at the following form of the [Newton's second] law. When any number of forces act on a body, the acceleration due to each force is the same in direction and magnitude as if the others had not been in action.”