Can gravity be reversed

[kycoldroller]

I am new to this site and have 1 question but can't seam to find out how to get the anwser...my uestion is can earths gravity be reversed.....keep in mind..I'm not a genus or anything...just something I keep wondering about...any help ould be appriecated

[ydoaPs]

I am new to this site and have 1 question but can't seam to find out how to get the anwser...my uestion is can earths gravity be reversed.....keep in mind..I'm not a genus or anything...just something I keep wondering about...any help ould be appriecated

 

I'm not exactly sure what you're trying to ask. What you you mean by reversing gravity?

[jackson33]

My guess would be he/she is thinking the electromagnetic field and not gravity. Yes, this field can reverse and well over due. What your compass now shows as north would then point south. Google the bold print and check it out....

[swansont]

Gravity is attractive. There's now way we know of to make gravity repel anything.

[michel123456]

Gravity is attractive. There's now way we know of to make gravity repel anything.

 

Isn't repelling gravity the basis of inflation theory?

[AlphaSheeppig]

My guess would be he/she is thinking the electromagnetic field and not gravity.

I think he means like some sort of antigravity that would make things fly instead of fall.

[swansont]

Isn't repelling gravity the basis of inflation theory?

 

Inflation and dark energy (the proposed cause) aren't really within the context of the OP, which specifically mentions earth's gravity.

[michel123456]

Well in this case, there is a way to make gravity null. When you accelerate at 9,81 m/s^2 in direction of the center of the Earth, you feel no gravity: it is called free falling. If you accelerate more, you will feel a force pushing you back: I guess it is repelling gravity in some sense.

[swansont]

Well in this case, there is a way to make gravity null. When you accelerate at 9,81 m/s^2 in direction of the center of the Earth, you feel no gravity: it is called free falling. If you accelerate more, you will feel a force pushing you back: I guess it is repelling gravity in some sense.

 

No, it's not repelling gravity by any sense. It's a different force altogether. IOW, a lift/elevator is not an antigravity device.

[michel123456]

The weird thing with gravity is that it is an acceleration without movement.

Once movement is used, it becomes indistinguishable from force induced by regular acceleration.

[DJBruce]

The weird thing with gravity is that it is an acceleration without movement.

Once movement is used, it becomes indistinguishable from force induced by regular acceleration.

 

If you were to drop an object from any height you can notice the movement associated with the acceleration caused by the force of gravity.

[michel123456]

Correct.

The association of the two facts that:

1. free falling is a state where you feel no gravity (can we call that a zero state?)

2. motion is relative

make me wonder whether in fact gravity is not the result of an imperceptible (accelerated) motion. Sorry if I go on & on about the same incongruous idea.

[swansont]

The weird thing with gravity is that it is an acceleration without movement.

Once movement is used, it becomes indistinguishable from force induced by regular acceleration.

 

 

 

Movement or no, gravity is always indistinguishable from acceleration due to some other force. That's the equivalence principle.

[dragonstar57]

every force has a opposite right? so it seams like there would be some kind of "repulsion gravity"

maybe it would have something to do with the -mas I have heard about recently that some people think exist

[swansont]

every force has a opposite right?

 

Does it? The strong interaction is always attractive.

 

http://en.wikipedia.org/wiki/Strong_interaction

[Mr Skeptic]

every force has a opposite right? so it seams like there would be some kind of "repulsion gravity"

maybe it would have something to do with the -mas I have heard about recently that some people think exist

 

No, you need to go study Newton's laws of motion again. If I pull on a string I exert a force and there is an equal and opposite force pulling the other direction (the tension of the string in this case). For gravity the equal and opposite force is the gravitational effect of the second body on the first.

[dragonstar57]

oh right

but doesn't the theorized negative mass have negative gravity??

could this be used to make some kind of force field?

like discussed in

http://www.scienceforums.net/topic/51264-force-field-theory/

i don't see how EARTH could ever have negative gravity

but doesn't it exist in theory?

[Mr Skeptic]

Perhaps. If you plug a negative mass into the gravity equation, you'll get repulsive gravity. The only place I've seen gravity repulsion is with "dark energy" but no one knows what that is, much less how to manipulate it.

[michel123456]

Perhaps. If you plug a negative mass into the gravity equation, you'll get repulsive gravity. The only place I've seen gravity repulsion is with "dark energy" but no one knows what that is, much less how to manipulate it.

 

Correct me: negative mass implies negative energy, both of which completely unobserved, 100% speculative.

And negative energy is theoretically associated with reverse time.

In other words: positive mass is linked to positive energy, positive time and attractive gravity.

Reversely: negative mass must be linked to negative energy, negative time and repulsive gravity.

[Mr Skeptic]

Energy has a t^2 component, so reversing time won't reverse energy.

[swansont]

Unless you can show that inertial and gravitational mass are not the same, negative mass does not really yield repulsion, at least the analogue to electrostatics that is usually implied. F=-GmM/r^2 is now positive, but for a negative mass a = F/m is negative, so the resulting acceleration vector gives you attraction toward the positive mass. You now have some peculiar situations — for the positive mass you get acceleration in the same direction, owing to the loss of the minus sign, and two negative masses feel an attractive force, but repel each other in terms of acceleration.

[Bob_for_short]

The weird thing with gravity is that it is an acceleration without movement.

Acceleration is a movement feature by definition. Gravity can be felt as a force without motion if it is compensated with an elastic force, for example.

 

Once movement is used, it becomes indistinguishable from force induced by regular acceleration.

If we speak of macroscopic bodies, the forces should be applied to each body piece proportionally to their masses. Normally we apply an external force at some point or on a surface smaller than the body size so there arise deformations inside the body. It never resembles the gravity action.

Edited August 13, 2010 by Bob_for_short

[Magnetic Space Suit]

i believe an individual in an negative world would perceive time exactly like we do as if it was moving forward. the only difference is in a negative world waves would be moving in a negative way thus gravity is a form of wave attraction or re condensation so the wave attraction in a negative massed world should be reversed and thus anti gravity properties should exist.

[icarus2]

For the motion of negative mass, negative gravity and repulsive gravity

I make simulation video of the negative mass.

 

Refers to below the explanation and video,

http://www.bautforum.com/showthread.php/105870

[Mr Skeptic]

Unless you can show that inertial and gravitational mass are not the same, negative mass does not really yield repulsion, at least the analogue to electrostatics that is usually implied. F=-GmM/r^2 is now positive, but for a negative mass a = F/m is negative, so the resulting acceleration vector gives you attraction toward the positive mass. You now have some peculiar situations — for the positive mass you get acceleration in the same direction, owing to the loss of the minus sign, and two negative masses feel an attractive force, but repel each other in terms of acceleration.

 

Would that also result in a violation of conservation of momentum and conservation of energy? It seems if the bolded part could happen you could use it to turn something, and yet technically the negative mass would cancel the energy and momentum. Peculiar indeed.