Quotes About Relativity

This phenomenon, called time dilation, leads to what is known as the twin paradox.

His new idea was published that month in what became yet another seminal Einstein paper, "Cosmological Considerations in the General Theory of Relativity." On the surface, it did indeed seem to be based on a crazy notion: space has no borders because gravity bends it back on itself.

The obvious yet still astonishing conclusion: with no such thing as absolute simultaneity, there is no such thing as "real" or absolute time.

The conception of the ether has again acquired an intelligible content, although this content differs widely from that of the ether of the mechanical wave theory of light… According to the general theory of relativity, space is endowed with physical qualities; in this sense, there exists an ether.

A century after his great triumphs, we are still living in Einstein's universe, one defined on the macro scale by his theory of relativity and on the micro scale by a quantum mechanics that has proven durable even as it remains disconcerting.

He made imaginative leaps and discerned great principles through thought experiments rather than by methodical inductions based on experimental data. The theories that resulted were at times astonishing, mysterious, and counterintuitive, yet they contained notions that could capture the popular imagination: the relativity of space and time, E=mc2, the bending of light beams, and the warping of space. Adding

Einstein's goal as he pursued his general theory of relativity was to find the mathematical equations describing two complementary processes: 1. How a gravitational field acts on matter, telling it how to move. 2. And in turn, how matter generates gravitational fields in spacetime, telling it how to curve. His head-snapping insight was that gravity could be defined as the curvature of spacetime, and thus it could be represented by a metric tensor. For more than three years he

was sitting in a chair in the patent office at Bern when all of a sudden a thought occurred to me," he recalled. "If a person falls freely, he will not feel his own weight." That realization, which "startled" him, launched him on an arduous eight-year effort to generalize his special theory of relativity and "impelled me toward a theory of gravitation."16 Later, he would grandly call it "the happiest* thought in my life.

With his special theory of relativity, Einstein had shown that space and time did not have independent existences, but instead formed a fabric of spacetime.

It is very important to note, however, that the theory of relativity does not mean that "everything is relative." It does not mean that everything is subjective. Instead

A decade after that, in 1915, he wrested from nature his crowning glory, one of the most beautiful theories in all of science, the general theory of relativity.

El de relatividad es un concepto sencillo. Afirma que las leyes fundamentales de la física son las mismas cualquiera que sea nuestro estado de movimiento.

The special theory of relativity that Einstein developed in 1905 applies only to this special case (hence the name): a situation in which the observers are moving at a constant velocity relative to one another—uniformly in a straight line at a steady speed—referred to as an "inertial reference system.

According to that theory, clocks in stronger gravitational fields run more slowly than those in weaker gravity.

The central idea of general relativity is that gravity arises from the curvature of spacetime

Two events which, viewed from a system of coordinates, are simultaneous, can no longer be looked upon as simultaneous events when envisaged from a system which is in motion relative to that system.

If light travels so fast, How come afternoons are so long?

I stood and pulled her up on two feet. "That depends." "On what?" "Whether you're looking at this through my eyes or yours.

Zero dwells at the juxtaposition of quantum mechanics and relativity; zero lives where the two theories meet, and zero causes the two theories to clash. A black hole is a zero in the equations of general relativity; the energy of the vacuum is a zero in the mathematics of quantum theory. The big bang, the most puzzling event in the history of the universe, is a zero in both theories. The universe came from nothing-and both theories break down when they try to explain the origin of the cosmos.

all things that seem good and evil are the opposite ends of one line, and it is difficult to say where evil ends and good begins, for these are comparative terms. A lesser good would seem evil when compared with a greater good, and the lesser evil in comparison with the greater evil would appear good. If there were no evil, good would not have been valued. Without injustice, justice would not have been appreciated. Therefore the whole of life's joy is expressed in duality.

Language is made up of names of comparable objects, and that which cannot be compared has no name.

I understood Einstein's general theory of relativity, which meant that I knew how to demonstrate every essential property of it in a page or less of concise and transparent work. It seemed to me that if you understood a theory, it shouldn't take weeks of calculations on an art pad to check its basic properties.

Thus, the double unification given by the equivalence principle becomes a triple unification: All motions are equivalent once the effects of gravity are taken into account, gravity is indistinguishable from acceleration, and the gravitational field is unified with the geometry of space and time. When worked out in detail, this became Einstein's general theory of relativity, which he published in full form in 1915.

In fact, the particle-antiparticle annihilation and the closing of the string is necessary, if the theory is to be consistent with relativity, meaning the theory is required to have both open and closed strings. But this means it must include gravity. And the difference between gravity and the other forces is naturally explained, in terms of the difference between open and closed strings. For the first time, gravity plays a central role in the unification of the forces.