"Gravity (from Latin gravitas 'weight') is a fundamental interaction which causes mutual attraction between all things that have mass."
The force that attracts two objects with mass towards each other. It is a fundamental force in the universe and is responsible for the motion of planets, stars, and galaxies.
Newton's Law of Gravitation: This law states that every particle in the universe attracts every other particle with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them.
Gravitational field: A gravitational field is a region of space around a massive object where a test particle would experience a force due to the presence of the massive object.
Acceleration due to gravity: It refers to the acceleration experienced by an object in the presence of a gravitational field.
Escape velocity: The minimum velocity required for a body to escape from the gravitational field of a massive object is called the escape velocity.
Kepler's Laws of Planetary Motion: These laws describe the motion of planets around the Sun, and the relationship between their distance from the Sun, their orbital velocity, and their period of revolution.
Tides: Tides are caused by the gravitational force of the Moon and the Sun on the Earth's oceans and are an important aspect of the study of gravity.
Black Holes: Black Holes are regions of space where the gravitational field is so strong that nothing, not even light, can escape from it.
Gravitational waves: These are ripples in the fabric of spacetime caused by the acceleration of massive objects, such as black holes or neutron stars.
Inertial and gravitational mass: These are two different types of mass that describe the response of an object to two distinct kinds of forces, inertia and gravity.
General Theory of Relativity: This is Einstein's theory of gravity that describes gravity in terms of the curvature of spacetime by massive objects.
Newtonian Gravity: This is the gravity described by Isaac Newton's law of universal gravitation, which states that every particle in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
General Relativity: This is the theory of gravity developed by Albert Einstein, which describes gravity as the curvature of spacetime caused by the presence of mass and energy.
Quantum Gravity: This is the hypothetical theory that attempts to reconcile general relativity with quantum mechanics, which is the theory of the behavior of matter and energy at the smallest scale.
Dark Gravity: This is the hypothetical force that some scientists believe could explain the effects of dark matter and dark energy on cosmological scales.
Brane Gravity: This is a theory that proposes that our universe is a three-dimensional membrane (brane) floating in a higher-dimensional space, and that gravity is confined to the brane and its effects are felt across the higher-dimensional space.
Modified Gravity: This is a class of theories that propose modifications to the laws of gravity to explain observations that cannot be explained by Newtonian or General Relativistic theories.
Gravitational Waves: These are ripples in spacetime caused by the acceleration of massive objects, which were predicted by Einstein's theory of general relativity and were first observed in 2015.
"Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force, and 1029 times weaker than the weak interaction."
"As a result, it has no significant influence at the level of subatomic particles."
"However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light."
"On Earth, gravity gives weight to physical objects, and the Moon's gravity is responsible for sublunar tides in the oceans."
"Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing the circulation of fluids in multicellular organisms."
"The gravitational attraction between the original gaseous matter in the universe caused it to coalesce and form stars which eventually condensed into galaxies."
"Gravity has an infinite range, although its effects become weaker as objects get farther away."
"Gravity is most accurately described by the general theory of relativity, which describes gravity not as a force, but as the curvature of spacetime, caused by the uneven distribution of mass."
"The most extreme example of this curvature of spacetime is a black hole, from which nothing—not even light—can escape once past the black hole's event horizon."
"However, for most applications, gravity is well approximated by Newton's law of universal gravitation, which describes gravity as a force causing any two bodies to be attracted toward each other, with magnitude proportional to the product of their masses and inversely proportional to the square of the distance between them."
"Current models of particle physics imply that the earliest instance of gravity in the universe, possibly in the form of quantum gravity, supergravity, or a gravitational singularity, developed during the Planck epoch (up to 10−43 seconds after the birth of the universe)."
"Scientists are currently working to develop a theory of gravity consistent with quantum mechanics, a quantum gravity theory, which would allow gravity to be united in a common mathematical framework (a theory of everything) with the other three fundamental interactions of physics."