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The 12th-century scholar Al-Khazini suggested that the gravity an object contains varies depending on its distance from the centre of the universe (referring to the centre of the Earth). Al-Biruni and Al-Khazini studied the theory of the centre of gravity, and generalized and applied it to three-dimensional bodies.
The anthropic principle, also known as the observation selection effect, is the proposition that the range of possible observations that could be made about the universe is limited by the fact that observations are possible only in the type of universe that is capable of developing intelligent life.
In physics, gravity (from Latin gravitas 'weight' [1]) is a fundamental interaction primarily observed as a mutual attraction between all things that have mass.Gravity is, by far, the weakest of the four fundamental interactions, approximately 10 38 times weaker than the strong interaction, 10 36 times weaker than the electromagnetic force, and 10 29 times weaker than the weak interaction.
A theory of gravity is a "metric theory" if and only if it can be given a mathematical representation in which two conditions hold: Condition 1 : There exists a symmetric metric tensor g μ ν {\displaystyle g_{\mu \nu }\,} of signature (−, +, +, +), which governs proper-length and proper-time measurements in the usual manner of special and ...
Before Newton's law of gravity, there were many theories explaining gravity. Philoshophers made observations about things falling down − and developed theories why they do – as early as Aristotle who thought that rocks fall to the ground because seeking the ground was an essential part of their nature.
Our understanding of gravity is still a work in progress. But the phenomenon of gravity, like evolution, is an accepted fact. Note that the term theory would not be appropriate for describing untested but intricate hypotheses or even scientific models.
He published a Lorentz invariant theory on four-dimensional spacetime, where gravity is transmitted by gravitational waves that travel at the speed of light. As Einstein later said, the reason for the development of general relativity was the preference of inertial motion within special relativity , while a theory which from the outset prefers ...
1902 – Paul Gerber explains the movement of the perihelion of Mercury using finite speed of gravity. [31] His formula, at least approximately, matches the later model from Einstein's general relativity, but Gerber's theory was incorrect. 1902 – Henri Poincaré questions the concept of simultaneity in his book, Science and Hypothesis. [32] [33]