Search results
Results from the WOW.Com Content Network
The force of gravity on the surface of the Earth, normally denoted g, has remained constant in both direction and magnitude since the formation of the planet. [citation needed] As a result, both plant and animal life have evolved to rely upon and cope with it in various ways. For example, humans employ internal models in motor planning that ...
Gravitropism (also known as geotropism) is a coordinated process of differential growth by a plant in response to gravity pulling on it. It also occurs in fungi. Gravity can be either "artificial gravity" [clarification needed] or natural gravity. It is a general feature of all higher and many lower plants as well as other organisms.
This is a list of most likely gravitationally rounded objects (GRO) of the Solar System, which are objects that have a rounded, ellipsoidal shape due to their own gravity (but are not necessarily in hydrostatic equilibrium). Apart from the Sun itself, these objects qualify as planets according to common geophysical definitions of that term.
Observations of these quasars and active galactic nuclei are difficult, and interpretation of the observations is heavily dependent upon astrophysical models other than general relativity or competing fundamental theories of gravitation, but they are qualitatively consistent with the black hole concept as modeled in general relativity.
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.
In general, their ground states tend towards a prolate shape, [33] although experimental data hint at oblate ground-state shapes in certain nuclei, for example krypton-72. [34] Experiments also suggest that some heavy nuclei, such as barium-144 and radium-224, possess asymmetric pear shapes evidenced by their measured octupole moments.
For two pairwise interacting point particles, the gravitational potential energy is the work that an outside agent must do in order to quasi-statically bring the masses together (which is therefore, exactly opposite the work done by the gravitational field on the masses): = = where is the displacement vector of the mass, is gravitational force acting on it and denotes scalar product.
Depending on which features of general relativity and quantum theory are accepted unchanged, and on what level changes are introduced, [204] there are numerous other attempts to arrive at a viable theory of quantum gravity, some examples being the lattice theory of gravity based on the Feynman Path Integral approach and Regge calculus, [191 ...