J.C.MacSwell

That is the problem I would have with the example you gave. How can the mass of a system be less than the sum of it's parts?

Possibly. I have always had a problem with what seemed to me an arbitrary (though convenient at times) choice of having gravitational PE as negative. It's something I would like to have a better grasp of.

Keep in mind that the mass of the system is greater than the sum of the masses of it's constituent parts. The system has a different rest frame than M1, which is different again from M2.

I think that would have to be correct. If gravitational radiation is detectable as per recent news, then their has to be associated energy in the detection. No matter what the source of the Earth's movement, "Theia whacking" or whatever, the satellite will be responding to the changes in Earth's position.

Like a satellite going around the Earth as the Earth accelerates toward the Sun?

Essentially Feynman showed that, at the same temperature throughout, the mechanism is as at least as likely to slip as it is to consolidate a gain in potential energy. It can be hard to pick out the flaws, but generally every scheme that tries to beat the second law of thermodynamics to produce useful energy at a macroscopic level can be shown why it won't work...and of course no one has ever built a mechanism of that type that works

Sounds similar in objective to a Maxwell's Demon or Brownian Ratchet, trying to beat the second law of thermodynamics... https://en.wikipedia.org/wiki/Maxwell%27s_demon https://en.wikipedia.org/wiki/Brownian_ratchet

Line 1: Two different circumstances 1)The 1:1 change between PE and KE is with no drag for an elliptical orbit...add a drag component and you change the ratio, generally not to any special 2:1:1 PE:KE:Drag split 2)The 50:50 ratio between KE and drag losses, which split the PE change, is generally approximate for a slowly decaying, substantially circular, orbit Line 2: It does not have to be that way. The ratios depend on the resultant forces at any given point. Quantum considerations are insignificant here Line 3: You can get other ratios Line 4: A decaying long elliptical orbit will have varying ratios. This can be readily seen by comparing the resultant forces and velocities at various points. It's fairly simple Newtonian mechanics at any given point, even if more complex to track over time.

In a slowly decaying almost circular orbit there is a approximate 50:50 split of the PE change(100%), between drag loss(50%) and KE gain(50%). A change in the drag will, at least temporarily, change these ratios, and of course in elliptical orbits they are changing in (almost) any case.

Studiot was just trying to keep up with the "dirtyness" of the thread...

That's right. Same speed but different direction.

Except of course, like a broken clock being right twice per day...for elliptical orbits KE = 1/2 |PE| holds twice per orbit

I assumed an instantaneous slowing with no change in direction...an idealized impulse in the same direction as any would be drag. Once this takes place the body is free in the elliptical orbit, and will follow the path of that orbit.

After impact and forever in an ideal Newtonian case, once per elliptical orbit, until something changes the system. GR is different but that would be off topic.

You suggested only one impact in the post I replied to. My reply was with respect to that.

You will have impulsed it to slow it down, then left it in an eccentric orbit with no further drag. It should come around to that exact same spot and same velocity you left it. (assuming Newton not Relativity)

Do a free body diagram of a body in free circular orbit entering a drag zone. It slows down (temporarily) as their is a aftward component of the net force from the drag, with the gravitational force being normal to the direction of travel. Do a second of a body in almost the same orbit but in a decaying orbit from being in a drag zone for some time. It speeds up as their is a persistent forward component of the net force, since their will be a gravitational forward component that is approximately twice the drag force. Put the two together with a smooth transition in between and you have essentially what Swanaont described earlier:

That's correct. If on that path the drag stops the orbit would revert to an ellipse, speeding up initially. Sorry if I pulled things slightly off topic when quoting Swansont from 2005. If you compare circular orbits at different heights, the PE difference is twice that the KE difference. While slowly decaying it would be approximately that.

I knew we had discussed this before...just hadn't realized it was over 10 years ago! http://www.scienceforums.net/topic/13482-is-the-earth-losing-energy/ From Swansont vintage 2005 (answer might seem opposite but it is opposite of a decaying orbit as it is with regard to the moon getting further away) Is this is exactly right? A slowly decaying orbit speeds up. If you do a free body diagram on the satellite the net force will be ever so slightly forward, not of it's would be no drag path, but of it's new spiral path. Until that change in direction occurs (from,say perfectly circular orbit) the net force is still slightly aft, and a one time slowing would occur as described by Swansont.

I think there is a delay for the light in that sweet spot, equidistance, between identical (and somehow fixed in space?) black holes, but it finally comes out at the same frequency it went in. Similar to MigL's analogy in that there is a delay but momentum is eventually the same.

With regard to whether the machine could work. You also need a changing magnetic field. So even if you expand your isolated system to include the magnetic field, you need a further external source of energy to drive it.

Are you sure that is the right context of the question? Free fall does not take place on an angled plane.

Just a point. That would only be additional if the energy to create the spinning came from outside the system.

Not sure if this is any help, certainly best to discuss with your physician, but lifestyle (diet, exercise, weight management) can help with chronic inflammation. http://www.wholeliving.com/134407/4-steps-reducing-chronic-inflammation

Simplest case…it would wobble off in the opposite direction.