Quotes About Gravitational

Gravitational and electromagnetic interactions are long-range interactions, meaning they act on objects no matter how far they are separated from each other.

Just as inertial mass and gravitational mass are equivalent, so too there is an equivalence, he realized, between all inertial effects, such as resistance to acceleration, and gravitational effects, such as weight. His insight was that they are both manifestations of the same structure, which we now sometimes call the inertio-gravitational field.

His theory indicated that the universe would have to be either expanding or contracting, not staying static. According to his field equations, a static universe was impossible because the gravitational forces would pull all the matter together.

A singularity is a point or region in spacetime at which some physical quantity such as the density of mass or energy, the temperature, or the strength of the gravitational field, becomes infinite. Whenever they happen, they pose serious difficulties for physics because they signal a breakdown in the description of the world in mathematical terms.

But Einstein was not the best mathematician around, and others, undeterred by neither the difficulty of the equations nor the war that was ravaging Europe (this was 1916), were able to find solutions. Some of the most important solutions ever found—those that describe the gravitational fields of stars and black holes—were written down by a German officer named Karl Schwarzchild as he lay dying in a field hospital of a skin disease he had picked up in the trenches.

For simple black holes, which do not rotate and have no electric charge, the values of the temperature and entropy can be expressed very simply. The area of the horizon of a simple black hole is proportional to the square of its mass, in Planck units. The entropy S is proportional to this quantity. In terms of Planck units, we have the simple formula S = .25 A / h G. Where A is the area of the horizon, and G is the gravitational constant.

If a Creator designed our universe to support life, he did a terrible job. In the vast, vast majority of the cosmos, life would die instantly from lack of atmosphere, gamma-ray bursts, deadly pulsars, and crushing gravitational fields. Believe me, the universe is no Garden of Eden.

What nobody knew about the docile girl from Osogbo was that her heart was too heavy, and that almost from birth she had felt its weight, a gravitational pull that invited her to her grave. Her heart was heavy because it was open, and so things filled it, and so things rushed out of it, but still the heart kept beating, tough and frighteningly powerful and meaning to shrug off the rest of her and continue on its own.

Moon's gravitational pull means that earth doesn't wobble too much. Scientists call it obliquity. The moon holds us fast.

It's a spectacular signal. It's a signal many of us have wanted to observe since the time LIGO was proposed. It shows the dynamics of objects in the strongest gravitational fields imaginable, a domain where Newton's gravity doesn't work at all, and one needs the fully non-linear Einstein field equations to explain the phenomena.

For relatively small stars, the Pauli exclusion principle keeps the electrons in a star sufficiently separated to prevent the star from contracting further after it has spent its fuel. In other words, the electrons counteract the crushing gravitational force. However, for stars more than about 1.5 times the mass of the sun (a mass known as the Chandrasekhar limit), this repulsive force would not be enough to stop stellar collapse.

The hazards posed by Near-Earth Asteroids are assessed by Sentry, a computer system developed by the Near-Earth Objects Group at NASA's Jet Propulsion Laboratory in Pasadena, Calif. The software factors together a cosmic rock's coordinates, distance, velocity, and gravitational influences to calculate its trajectory.

Desire demands only a constant attention to the unknown gravitational field which surrounds us and from which we can recharge ourselves every moment, as if breathing from the atmosphere of possibility itself. A life's work is not a series of stepping-stones onto which we calmly place our feet, but more like an ocean crossing where there is no path, only a heading, a direction, which, of itself, is in conversation with the elements.

Only three constants are significant for star formation: the gravitational constant, the fine structure constant, and a constant that governs nuclear reaction rates.

Spacetime can be so warped that the gravitational field becomes highly concentrated in a small region near a brane—so concentrated that the huge expanse of an infinite dimension is inconsequential.

Planck minimums of space and time all the way to the gravitational fine-structure constant.

Finally, Dr. Sean C. Solomon of MIT reported (in Astronautics, February 1962) that "The Lunar Orbiter experiments vastly improved our knowledge of the moon's gravitational field indicating the frightening possibility that the moon might be hollow." Frightening? What, indeed, is the significance of that word? The significance was mentioned by no less a figure than the late and great astronomer Carl Sagan in his book Intelligent Life in the Universe (1966).

I hope that vigorous space exploration continues and that humankind will have a space station that resides between Earth and the moon. Outside the gravitational field of Earth, we could launch robotic spacecraft to other destinations in our solar system.

Dark matter has a gravitational effect on other objects. You can't see it, you can't feel it, but you can watch something being pulled in its direction.

Prior to then it was believed that black holes were just cosmic cookie monsters, swallowing everything that came within their gravitational clutches.

The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.

I could feel the gravitational pull of home, which when I'm home too long becomes the gravitational pull of somewhere else.