>So if you could extract useful energy from the earth's rotation it would mean >it is possible to violate the conservation of angular momentum.<
Harry, are you trying to set a sneaky word trap? Closed system is the key phrase here. You can borrow angular momentum from one portion of the closed system to give to another portion but the overall angular momentum of the system is conserved. Therefore, you can not take angular momentum from a closed system and turn it into heat. You can take angular energy that is typically available in a rotating closed system and convert that into heat such as with a braking device. That is different. The RAR device might somehow borrow angular momentum from the Earth for a period of time, but the complete system momentum will be conserved. Dave -----Original Message----- From: H Veeder <hveeder...@gmail.com> To: vortex-l <vortex-l@eskimo.com> Sent: Sun, Feb 9, 2014 9:02 pm Subject: Re: [Vo]:: RAR gravity engine So if you could extract useful energy from the earth's rotation it would mean it is possible to violate the conservation of angular momentum. Harry On Sun, Feb 9, 2014 at 8:48 PM, David Roberson <dlrober...@aol.com> wrote: As you say, the rotation rate of the Earth can be modified by devices located on the earth. The issue is that whatever you use to modify that rotation must not change the overall angular momentum of the system which includes the Earth and that device. For example the bullet fired by the gun below could change that rotation rate until it comes to rest again on the Earth. Of course, the rate could be changed if the bullet does not return to the exact same location as it began if you really want to get technical. Remember, it is angular momentum that is conserved, not rotation rate alone. The location of the bullet at rest might lead to a different moment of inertia for the system. Dave -----Original Message----- From: H Veeder <hveeder...@gmail.com> To: vortex-l <vortex-l@eskimo.com> Sent: Sun, Feb 9, 2014 8:09 pm Subject: Re: [Vo]:: RAR gravity engine Yes, but those laws do not prohibit the Earth's rotation from being slowed (or quickened) by means located only on the Earth. (e.g. on a smaller scale a satellite's spin can be slowed by using the built in control thrusters.) Those laws only say it is impossible to generate useful energy from the Earth's rotation by means only located on the Earth. Harry On Sun, Feb 9, 2014 at 6:46 PM, David Roberson <dlrober...@aol.com> wrote: Strange as it may seem, any activation force or torque is going to result in a reaction that keeps the total momentum in balance. When a bullet is fired from a gun momentum is conserved since the gun is driven backwards with an amount of momentum equal to that carried away by the bullet. The gun is much heavier than the bullet so it recoils at a far lower velocity. In this case the energy imparted upon the bullet is much greater than that delivered to the gun since energy is proportional to velocity squared. That is a good reason to have a heavy weapon. :-) Angular momentum works in a similar manner. The key thing to remember is that both linear and angular momentums are conserved. Any force you generate is matched by a reaction force of equal and opposite magnitude. Dave -----Original Message----- From: H Veeder <hveeder...@gmail.com> To: vortex-l <vortex-l@eskimo.com> Sent: Sun, Feb 9, 2014 5:37 pm Subject: Re: [Vo]:: RAR gravity engine The initial momentum of the pendulum does not have to come from the rotation of the earth. It could come from some chemical energy such as a muscle or a bomb. Harry
