Near the beginning of his career, Einstein thought that Newtonian mechanics was no longer enough to reconcile the laws of classical mechanics with the laws of the electromagnetic field. This led to the development of his special theory of relativity. He realized, however, that the principle of relativity could also be extended to gravitational fields, and with his subsequent theory of gravitation in 1916, he published a paper on the general theory of relativity.

He continued to deal with prob...

Philosophiæ Naturalis Principia Mathematica (Latin for Mathematical Principles of Natural Philosophy), often referred to as simply the Principia, is a work in three books by Isaac Newton, in Latin, first published 5 July 1687. After annotating and correcting his personal copy of the first edition, Newton published two further editions, in 1713 and 1726. The Principia states Newton's laws of motion, forming the foundation of classical mechanics; Newton's law of universal gravitation; and a de...

THIS BOOK is not intended as an abstruse scientific work, but the statement of a new theory, and its comparison with the old ones for the instruction of the masses. It is well said, " every age has its predominant thought."

That of Greece was beauty, and she excelled in sculptured grace of statue and temple ; that of Rome was power and she conquered the world ; that of the sixteenth century was reform, and states and religions were torn into warring fections ; that of the eighteenth century w...

"Physics is all around us. It is in the electric light you turn on in the morning; the car you drive to work; your wristwatch, cell phone, CD player, radio, and that big plasma TV set you got for Christmas. It makes the stars shine every night and the sun shine every day, and it makes a baseball soar into the stands for a home run.

Physics is the science of matter, energy, space, and time. It explains ordinary matter as combinations of a dozen fundamental particles (quarks and leptons), inter...

"I don’t want to bore you with the over and over told stories of the wave-particle duality and Schroedinger’s Cat…

May be there are hundreds of books that do this. But I tell you a different and deeply story so relation to the paralel universe that contain from ancient Upanishads to modern String theory and beyond with simply forming “Four Equations” and “Four Stories” in simple “Four Steps”.."

"She is both dead and alive according to some left brains. But I want to give you...

Einstein has succeeded in separating far more completely than hitherto the share of the observer and the share of external nature in the things we see happen. The perception of an object by an observer depends on his own situation and circumstances; for example, distance will make it appear smaller and dimmer. We make allowance for this almost unconsciously in interpreting what we see. But it now appears that the allowance made for the motion of the observer has hitherto been too crude|a fact...

Philosophiæ Naturalis Principia Mathematica (Latin for Mathematical Principles of Natural Philosophy), often referred to as simply the Principia, is a work in three books by Isaac Newton, in Latin, first published 5 July 1687. After annotating and correcting his personal copy of the first edition, Newton published two further editions, in 1713 and 1726. The Principia states Newton's laws of motion, forming the foundation of classical mechanics; Newton's law of universal gravitation; and a de...

It was about sixty years ago when there appeared the first glimmerings Of the knowledge which has since ripened into that which we now possess, that neither the molecules of any natural object nor the parts Of which those molecules consist are ever at rest; that, on the contrary, swift and orderly movements are ever in progress among them and within them; and that where bodies appear to us to be stationary, it is only be cause this great internal activity is on too small a scale, the parts mo...

In these days of numerous text-books the author who dares still further to increase the number owes to the public, at least, an explanation in which he shall set forth his purpose, however far short of accomplishment he may have fallen.

Accordingly, in this volume, the author's hopes have been: –

(i) To prepare a text-book adapted to the needs of first-year students in physics at Northwestern University. One fear in this connection is that the transfer of a course of lectures from flexible...