This is one of the big questions in science. Anyone wanna take a swing at it?

People have been swinging at this one for as long as people have been asking questions and no-one has hit it yet Gravity and time share the common link in that we can accurately measure and predict their effects, but have no real idea what they actually are.

Answering a question on the effects of gravity is a straightforward matter, how it works is, and will remain, unknown I feel.

it has quite a bit to do with how the earth rotates on its axis, as well as how the earth rotates in its orbit of the sun



IMO

While gravity is very well described by theory as the effect mass and energy have on spacetime, it is still unclear how this fits in with our other accurate descriptions of reality, i.e. waves and particles.
This is currently one of the biggest problems confronting modern physics, and to complicate matters there seems to be more gravity and energy in the universe than visible matter can account for.

So basically we're shit out of luck until we can harvest massive amounts of experimental data to test front-running theories - like string theory - which have yet to be subjected to nature's arbitration
Time will tell.

This post was edited by heepajunk on Apr 12 2009 05:55am

this is some good trolling. even if you didn't mean to, just look at the question you've asked. damn.

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 it accounts for the very 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 that we observe. 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 excellent approximation for most calculations.

The terms gravitation and gravity are mostly interchangeable in everyday use, but a distinction may be made in scientific usage. "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.

... Not only did you not answer the question, but you pointed out the obvious. Yes, we know gravity holds stuff together lol -- just ignore this entire thread, its spam / trolling and unanswerable.

gravity is a force pulling together all matter (which is anything you can physically touch). the more matter, the more gravity, so things that have a lot of matter such as planets and moons and stars pull more strongly.

This post was edited by jimmy123 on Apr 16 2009 07:17pm

It'll help if you envision the universe as a big blanket (this represents space). If you lob a large, heavy object onto that blanket, it will push the blanket down. Then, if you roll a ball along the now inclined-surface surrounding that heavy object, it will accelerate. In fact, it accelerates faster if the object is heavier, as heavier objects will cause more of a slope in that inclined surface. That's the impact of gravitational acceleration and the mass of the object: heavier/denser object = larger g. I guess that effectively explains it.

agreed. but what's confusing is how orbits are elipses, not spherical; since the sun and all the planets are in that general shape
it would be caused by the other stars in the galaxy and the planets, would it not?