Gravity from spacetime curvature

[marthkiki]

After a while of trying to understand this, it's still kind of confusing. I get how the planets orbit around the sun because of the sun's spacetime curve, but if one were to drop something, how does spacetime curvature cause it to fall? How can everything in the universe have a gravitational effect on one another? Is it because the spacetime curvature from all objects extends to an infinite range?

 

[A.T.]

but if one were to drop something, how does spacetime curvature cause it to fall?

In simple terms:
http://www.physics.ucla.edu/demoweb..._and_general_relativity/curved_spacetime.html
http://www.relativitet.se/spacetime1.html
http://www.adamtoons.de/physics/gravitation.swf

 

[Entropia]

Gravity from spacetime curvature can be a difficult concept to grasp, but it is a fundamental principle in understanding the behavior of objects in our universe. To answer your question about how spacetime curvature causes objects to fall, we must first understand that spacetime is not a flat surface, but rather a dynamic, four-dimensional fabric that is affected by the presence of mass and energy.

When an object, such as a planet, is in the vicinity of a massive object like the sun, its presence causes a curvature in spacetime. This curvature is what we experience as gravity. Just like how a bowling ball placed on a mattress causes a depression in the fabric, the sun's mass causes a curvature in spacetime, and the planets follow this curvature as they orbit around it.

As for why everything in the universe has a gravitational effect on one another, it is because all objects, regardless of their size, have a mass and therefore create a curvature in spacetime. This means that even the smallest objects, like a pebble, have a gravitational effect on other objects. However, the strength of this effect is directly proportional to the mass of the object. So while a pebble may have a gravitational effect on other objects, it is much smaller compared to the gravitational effect of a planet or a star.

It is important to note that the range of the gravitational effect of an object is not infinite. It is limited by the mass and size of the object, as well as the strength of its gravitational pull. This is why the gravitational force between two objects decreases as the distance between them increases.

In summary, gravity from spacetime curvature is a result of the presence of mass and energy in the universe, which causes a curvature in spacetime. This curvature is what we experience as gravity and is responsible for the motion of objects in our universe. While it may be a complex concept, it is essential in understanding the fundamental forces that govern our universe.