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Do astronauts experience 'space headaches'?

Space travel and zero gravity can take a toll on the body. A new study has found that astronauts with no prior history of headaches may experience migraine and tension-type headaches during long-haul space flight, which includes ...

Gravitation

Gravitation is a natural phenomenon by which objects with mass attract one another. In everyday life, gravitation is most commonly thought of as the agency which lends weight to objects with mass. Gravitation compels dispersed matter to coalesce, thus accounting for the existence of the Earth, the Sun, and most of the macroscopic objects in the universe. It is responsible for keeping the Earth and the other planets in their orbits around the Sun; for keeping the Moon in its orbit around the Earth; for the formation of tides; for convection, by which fluid flow occurs under the influence of a temperature gradient and gravity; for heating the interiors of forming stars and planets to very high temperatures; and for various other phenomena observed on Earth. Modern physics describes gravitation using the general theory of relativity, in which gravitation is a consequence of the curvature of spacetime which governs the motion of inertial objects. The simpler Newton's law of universal gravitation provides an accurate approximation for most calculations.

The terms gravitation and gravity are mostly interchangeable in everyday use, but a distinction is made in scientific circles. "Gravitation" is a general term describing the phenomenon by which bodies with mass are attracted to one another, while "gravity" refers specifically to the net force exerted by the Earth on objects in its vicinity as well as by other factors, such as the Earth's rotation.

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