Exchemist quote “I defy you to invent any scenario in which the block and sphere can spontaneously alter such that you have a block at rest and a sphere moving at 20m/sec.”
I do it all the time; I have dozen of such devices. The 20 m/sec would be a 20 to 1 cylinder to spheres mass ratio. That mass ratio would be in the cart wheel class. I use a 2.6 kilogram cart wheel to throw two 66 gram spheres. But these are not scenarios; they are real working devices.
I argue that heat can not be produced because you get 100% back.
You argue that you can not get 100% back because heat is produced.
The following is a real experiment.
I have a cylinder and spheres experiment where it takes 4 frames (from a camera taking 240 frames per second) for the cylinder surface to cross 20 mm at the beginning of the experiment. And then the spheres completely stop the cylinder: the cylinder surface is stopped.
The spheres then restart the cylinder and: it takes four frames for the cylinder surface to cross 20 mm in the middle of the experiment. And then the spheres completely stop the cylinder.
The spheres then restart the cylinder and: it takes four frames for the cylinder surface to cross 20 mm at the end of the experiment.
This is a real experiment not a scenario. There are two complete restorations of motion after two complete stops. This is exactly the experiment you are requesting. I can mail you a video of the experiment on a flash drive.
This is another experiment that might help;
Take a 2 kg PVC pipe (3 in. I.D.) and drill a hole through its diameter about an inch down from the top. Place a 60 pound test fluorocarbon string through the hole and place 50 gram spheres on the ends of the string. Affix the string so that the tethered spheres have equal lengths of about 1.5 times the pipe diameter . Wrap the tethers around the cylinder and hold the spheres up against the cylinder. Spin the cylinder and spheres at a rotational rate of .952 m/sec. And then release the spheres.
Now: We have 2.1 kilogram moving .952 meter per sec. This is .9524 joules of energy: and NASA predicts that when the 100 grams are at full extension (and the cylinder is stopped) the 100 grams will have .952 joules of energy. So; ½ * .100 kg *v * v = .9524 J; v = 4.3643 m/sec ; NASA predicts that the spheres will be moving 4.36 m/sec.
From a multitude of collision experiments we know that: When a small mass of .100 kilograms moving 4.36 m/sec collides with a larger mass of 2 kilogram the final velocity will be (.100 kg * 4.36 m/sec = 2.1 kg * v) v = .2076 m/sec. Therefore the origin velocity of .952 m/sec can not be obtained from the velocity NASA predicts.
Newton would predict that the .100 kilograms would be moving: 2.1 kg * .952 m/sec = .1 kg * v; v = 20 m/sec. This 20 m/sec would allow for a complete restoration of motion at the end of the experiment; and that is exactly what happens.
I think I could set up this experiment in about 20 minutes: but I would have to change the 100 grams into 132 grams because a tapped steel spheres have a mass of 66 grams each. And that would make me change the 2 kilograms pipe into a 132/100 * 2 = 2.64 kg pipe. Then I would have to mount the high speed camera: and of course the outcome would be the same as I have done dozens of times already. The data collected would show that Newton is correct and linear momentum is conserved.