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New Theories / Want to know a little about black holes... Here is an essay on the subject
« on: 13/12/2009 07:09:50 »
Sorry... I made a new one... I'll get a new link
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Farsight.. enough. You have seen my reply - your archiac science has no place when considering these things. Obviously if gravity is a physical force, it must have a work associated to it.
I don't think so. Mr S, I presume you are sitting on a chair. Gravity is exerting a force on you and the chair is reacting to that force to support your mass. While the chair continues to support that mass, no work is done. If the chair collapses and you fall to the ground, work has been done. Just because there is a force it does not mean work is being done.
Is the balancing you do to stay in an upright position constitute force still happening or does it become different from side to side why I ask this is that when I have passed out in my chair my body has slumped down and out of the chair to the ground where I find myself when I have come too, so is there not a constant work happening in just trying to sit upright in a chair to begin with?
I am not trying to be difficult but to understand as I am horrible with gravity and it is a difficult subject even with basic understandings...
Gravity is related to mass and acceleration. As soon as you stop accelerating you become 'weightless' if in space. So to get to a state without gravity I think you would need to be as far away from any mass and acceleration as possible.
Does anyone have any ideas how the earth or any other planet could lose its gravity?? either over a long or short amount of time..
any ideas would be appreciated, cheers.
As you can see I like to sit in the shower. Unfortunately I keep breaking the chairs.
Can you suggest a way I could support myself? As I am broke from lack of work. LOL
This is an interesting one, Joe. When we look at something as simple as a waterwheel, we say that gravity does do work. We get hydroelectric power from this, so it looks cut and dried.
But when we look deeper, we see there's something of a problem. Work is the transfer of energy, and if we examine two masses falling towards one another, we know from conservation of energy that no energy is added to the "system" that is those two masses. That's because energy causes gravity, and if energy was really being added, the gravity of the two combined masses would exceed the gravity of the two separate masses.
If the two masses spiralled around one another in a closing orbit and then fused gently and stayed cold, we wouldn't have extracted any work. If however we extracted work from the two masses falling together, the energy we extracted will be dissipated as heat. Then we know from E=mc² that the two masses will then weigh a little less. So the answer is: no, gravity doesn't do any work, but it does allow us to do work.