Quotes About Physics

When the conventional wisdom of physics seemed to conflict with an elegant theory of his, Einstein was inclined to question that wisdom rather than his theory, often to have his stubbornness rewarded.

See how the wings, striking against the air, sustain the heavy eagle in the thin air on high," he noted, then added, "As much force is exerted by the object against the air as by the air against the object."16 Two hundred years later, Newton would state a refined version of this as his third law of motion: "To every action there is always opposed an equal reaction.

He has departed from this strange world a little ahead of me. That means nothing. For us believing physicists, the distinction between past, present and future is only a stubborn illusion.

Physics should represent a reality in time and space, free from spooky action at a distance.

Physicists are not used to trimming or compromising their equations in order to get them accepted. Which is why they do not make good politicians. At

Einstein rejected the emission theory in favor of postulating that the speed of a light beam was constant no matter how fast its source was moving.

In other words, there is no single underlying reality that is independent of our observations. "It is wrong to think that the task of physics is to find out how nature is," Bohr declared. "Physics concerns what we can say about nature."62 This

The first half of the twentieth century, beginning with Albert Einstein's 1905 papers on relativity and quantum theory, featured a revolution driven by physics.

old physicist joke: they knew that the approach worked in practice, but could they make it work in theory?

So Einstein rejected the emission theory in favor of postulating that the speed of a light beam was constant no matter how fast its source was moving. "I came to the conviction that all light should be defined by frequency and intensity alone, completely independently of whether it comes from a moving or from a stationary light source," he told Ehrenfest.

The result was an elegant conclusion: mass and energy are different manifestations of the same thing. There is a fundamental interchangeability between the two.

fuerzas gravitatorias de Newton, por las que dos objetos se atraen mutuamente de manera directamente proporcional a su masa e inversamente proporcional a la distancia que los separa.

Over the ensuing years, researchers would discover new forces in nature, besides electromagnetism and gravity, and also new particles. These would make Einstein's attempts at unification all the more complex. But he would find himself less familiar with the latest data in experimental physics, and he thus would no longer have the same intuitive feel for how to wrest from nature her fundamental principles.

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.

Another way to describe the Second Law is in terms of entropy, the degree of disorder and randomness in a system. Any spontaneous process tends to increase the entropy of a system.

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.

Time cannot be absolutely defined, and there is an inseparable relation between time and signal velocity." More

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.

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.

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.

The resulting four-page paper, published in May 1935 and known by the initials of its authors as the EPR paper, was the most important paper Einstein would write after moving to America. "Can the Quantum-Mechanical Description of Physical Reality Be Regarded as Complete?" they asked in their title.