Gravity and Centrifugal Force do exist!

But I want to go along the tangent of the circle, and not along its radius. And another thing, what do you mean by a non-inerital reference frame?

Quote from: John Jackson on February 07, 2008, 06:44:18 PM

But I want to go along the tangent of the circle, and not along its radius. And another thing, what do you mean by a non-inerital reference frame?

An accelerating frame of reference.

Quote from: Trekky0623 on February 07, 2008, 06:46:31 PM

Quote from: John Jackson on February 07, 2008, 06:44:18 PM

But I want to go along the tangent of the circle, and not along its radius. And another thing, what do you mean by a non-inerital reference frame?

An accelerating frame of reference.

Acceleration is a relative term. It has no meaning unless you define the body with respect to which you are considering this acceleration.

Quote from: John Jackson on February 07, 2008, 06:48:11 PM

Quote from: Trekky0623 on February 07, 2008, 06:46:31 PM

Quote from: John Jackson on February 07, 2008, 06:44:18 PM

But I want to go along the tangent of the circle, and not along its radius. And another thing, what do you mean by a non-inerital reference frame?

An accelerating frame of reference.

Acceleration is a relative term. It has no meaning unless you define the body with respect to which you are considering this acceleration.

The point is, you feel a gravitational force when you are accelerated.

In RE, this is still a fictitious force explained by the bending of space-time.

Quote from: Trekky0623 on February 07, 2008, 06:50:13 PM

Quote from: John Jackson on February 07, 2008, 06:48:11 PM

Quote from: Trekky0623 on February 07, 2008, 06:46:31 PM

Quote from: John Jackson on February 07, 2008, 06:44:18 PM

But I want to go along the tangent of the circle, and not along its radius. And another thing, what do you mean by a non-inerital reference frame?

An accelerating frame of reference.

Acceleration is a relative term. It has no meaning unless you define the body with respect to which you are considering this acceleration.

The point is, you feel a gravitational force when you are accelerated.

In RE, this is still a fictitious force explained by the bending of space-time.

Well, if I am falling freely relative to the Earth, I am accelerated, but I feel weightless, don't I?

Quote from: John Jackson on February 07, 2008, 06:58:12 PM

Quote from: Trekky0623 on February 07, 2008, 06:50:13 PM

Quote from: John Jackson on February 07, 2008, 06:48:11 PM

Quote from: Trekky0623 on February 07, 2008, 06:46:31 PM

Quote from: John Jackson on February 07, 2008, 06:44:18 PM

But I want to go along the tangent of the circle, and not along its radius. And another thing, what do you mean by a non-inerital reference frame?

An accelerating frame of reference.

Acceleration is a relative term. It has no meaning unless you define the body with respect to which you are considering this acceleration.

The point is, you feel a gravitational force when you are accelerated.

In RE, this is still a fictitious force explained by the bending of space-time.

Well, if I am falling freely relative to the Earth, I am accelerated, but I feel weightless, don't I?

When in free fall, you are traveling at a constant velocity.  When you first jump out of a plane, you feel it.  It isn't until you reach terminal velocity that you feel weightless.

When you are in freefall, you are actually traveling inertially along a geodesic.  Therefore, you feel no force.  When you are standing on the earth, you are constantly being accelerated.  However, you sense yourself to be at rest, so in your mind, you create a fake force to describe what you are feeling. 

If you have mass, it means there is a force acting on you.

You are undergoing inertial motion when you travel along a geodesic.  You need to get out of Euclidean geometry.

General relativity is distinguished from other metric theories of gravitation by its use of the Einstein field equations to relate spacetime content and spacetime curvature.[2][3] The field equations are a system of partial differential equations whose solution gives the metric tensor of spacetime, describing its "shape". In the resulting geometry, an object moving inertially in a gravitational field is viewed as following a geodesic path that may be found using the Christoffel symbols of the metric. Solutions of the Einstein field equations model gravitating systems, especially important ones exhibiting spherical symmetry, notable examples being the Schwarzschild solution, the Reissner-Nordström solution and the Kerr metric.

I really wish you people would look stuff up for yourselves.

Quote from: Wiki

General relativity is distinguished from other metric theories of gravitation by its use of the Einstein field equations to relate spacetime content and spacetime curvature.[2][3] The field equations are a system of partial differential equations whose solution gives the metric tensor of spacetime, describing its "shape". In the resulting geometry, an object moving inertially in a gravitational field is viewed as following a geodesic path that may be found using the Christoffel symbols of the metric. Solutions of the Einstein field equations model gravitating systems, especially important ones exhibiting spherical symmetry, notable examples being the Schwarzschild solution, the Reissner-Nordström solution and the Kerr metric.

Stuff contained in spacetime...?

1)Energy, mass or momentum.
2)No.

Well, you said the only reason we say a force of gravity is acting on objects near Earth's surface is because we think we are in an inertial reference frame in which there exists a gravitational field, while, actually, our FoR is a non inertial one.

Then, you also said that freely falling bodies exhibit inertial motion along curved geodesics.

But, from your previous reasoning, it is clear that the curvature of space time is simply because we are in a non inertial FoR and not because of the mass of the Earth.

Quote

But, from your previous reasoning, it is clear that the curvature of space time is simply because we are in a non inertial FoR and not because of the mass of the Earth.

No.

But, from your previous reasoning, it is clear that the curvature of space time is simply because we are in a non inertial FoR and not because of the mass of the Earth.

Quote

Quote

Inventing inertial frames from non inertial ones is what causes the problem.

Can you explain please?

Taking a non inertial frame of reference and making it inertial is what gives us our fictitious forces.  Such as with gravity.  We are undergoing a constant acceleration, but we perceive ourselves to be at rest.  Thereby, changing our non inertial FoR into an inertial one.  In doing this transformation, we see that objects appear to accelerate towards the ground.  Since we are in an inertial FoR, we assume Newton's first two laws of inertia apply, so we assume there must be a force acting on the object, making it accelerate.  However, if we look at it outside of our inertial FoR, we would see that the object is the inertial one and we are non inertial.