## Dialogues Concerning Two New Sciences (Google eBook) |

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#### Dialogues Concerning Two New Sciences (On the Shoulders of Giants)

User Review - Not Available - Book VerdictThis new series offers five founding works of science reedited by Stephen Hawking, who also provides commentary. Each includes diagrams and theoretical models plus a biographical essay by Hawking. Read full review

### Common terms and phrases

accelerated motion acquired altitude amplitude Archimedes Aristotle ball bears body falling circle circumference clear cube cubits cylinder demonstrated descent described diameter diminishes distance AC draw elevation equal falling body falling from rest finite follows force Galileo GALILEO GALILEI given greater heavy body Hence heptagon horizontal line inclined plane indivisible infinite number interval larger length AC less lever Luca Valerio matter mean proportional medium momento momentum impeto moving body naturally accelerated parabola parallel particles perpendicular polygon portion prism projectile Proposition ratio represent required to traverse resistance rope Sagr Salv Salviati semi-parabola Simp Simplicio smaller solid space traversed specific gravity speed square starting from rest straight line string sublimity surface T. L. Heath tangent Theorem time-interval tion Trans triangle uniform motion vacuum velocita velocity vertical line vibrations weight

### Popular passages

Page 154 - ... path of some sort; however, no one has pointed out the fact that this path is a parabola. But this and other facts, not few in number or less worth knowing, I have succeeded in proving; and what I consider more important, there have been opened up to this vast and most excellent science, of which my work is merely the beginning, ways and means by which other minds more acute than mine will explore its remote corners.

Page 172 - BI are equal, since they are produced by the same momentum, gained by fall through CB, as experiment shows. Therefore all the momenta gained by fall through the arcs DB, GB, IB are equal. SAGR. The argument seems to me so conclusive and the experiment so well adapted to establish the hypothesis that we may, indeed, consider it as demonstrated. SALV. I do not wish, Sagredo, that we trouble ourselves too much about this matter, since we are going to apply this principle mainly in motions which occur...

Page 65 - an iron ball of one hundred pounds falling from a height of one hundred cubits reaches the ground before a one-pound ball has fallen a single cubit.

Page 58 - PROPOSITION 1 The area of any circle is equal to a right-angled triangle in which one of the sides about the right angle is equal to the radius, and the other to the circumference, of the circle.

Page 31 - ... of the difficulties which arise when we attempt with our finite minds to discuss the infinite, assigning to it those properties which we give to the finite and limited; but this I think is wrong, for we cannot speak of infinite quantities as being the one greater or less than or equal to the other.

Page 62 - But, even without further experiment, it is possible to prove clearly, by means of a short and conclusive argument, that a heavier body does not move more rapidly than a lighter one provided both bodies are of the same material and in short such as those mentioned by Aristotle.

Page 161 - ... we may picture to our mind a motion as uniformly and continuously accelerated when, during any equal intervals of time whatever, equal increments of speed are given to it.

Page 63 - ... clearly, by means of a short and conclusive argument, that a heavier body does not move more rapidly than a lighter one provided both bodies are of the same material and in short such as those mentioned by Aristotle. But tell me, Simplicio, whether you admit that each falling body acquires a definite speed fixed by nature, a velocity which cannot be increased or diminished except by the use of force [violenza] or resistance.

Page 167 - At present it is the purpose of our Author merely to investigate and to demonstrate some of the properties of accelerated motion (whatever the cause of this acceleration may be...

Page 215 - ... follows that motion along a horizontal plane is perpetual; for, if the velocity be uniform, it cannot be diminished or slackened, much less destroyed. Further, although any velocity which a body may have acquired through natural fall is permanently maintained so far as its own nature...