Physics behind the “force push”

When a gifted character uses "push" on something/someone, he/she doesnt get involved in action-reaction force pairs.

Here is some force on human body as an action. Where is the reaction? On the grount/ceiling? In some other dimension? Or just the air molecules at the same force-application spot(I dont see any wind there though)?

If there is no reaction force then it is just "free energy/momentum" income to the universe(not including extra dimensions). Is that why Palpatine exploded in his death, a release/implosion of all the energy he borrowed/lent through many years?

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Why the VTC as 'off topic'? Question 'relates directly to a cited work of fiction' which is permitted (and even mentioned) in the closure statement. – Stan Dec 10 '13 at 14:53

In general, the laws of conservation of energy/momentum in the Jedi universe aren't really laws... more like gentle suggestions. They either don't matter, or the situation (because of the Force) is never a closed system which is a prerequisite for such laws to apply.

Case in point: Yoda didn't move when lifting Luke's X-wing. A Jedi once moved an entire Star Destroyer. Yoda/Sidious were throwing heavy stuff around during their duels.

As best as I can tell from EU, the Jedi merely coaxes the Force to move things, instead of moving them himself. Think of it as pushing the gas pedal - you apply a miniscule amount of force, and a multi-ton car accelerates 0 to 60 miles and hour in seconds. YOU don't push the car. Or touching a button on a remote, and an enormous explosion from bomb whose detonator was wired to the remote results. Or you remove a small control rod from a nuclear pile and get fission reaction going.

Where the Force gets or puts the energy that is consumed/released is never actually spelled out in canon. It's The Force. (so your answer about Palpatine is "we don't have any idea").

In more physics terms analogy, imagine a heavy sphere standing on a very very small indentation on a gentle incline. The indentation causes the sphere to remain at rest for now. That sphere has a ton of potential energy. If the indentation is small enough, the sphere can be pushed out of it with minimal amount of energy/effort on your part - yet that gentle push will start the sphere rolling, and transforming its enormous potential energy into a great amount of kinetic energy.

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Star Wars in general makes physics want to go cry in a corner. The number of things the Death Star alone violates boggles the mind. – Jeff Dec 10 '13 at 13:53
This is a great explanation for something George Lucas likely wasn't thinking about when he wrote the original script. – Will F Dec 10 '13 at 14:33
@WillF, This is why (or rather, among the reasons why) Star Wars is sometimes described as "science fantasy" or "space fantasy" rather than "science fiction." – Brian S Dec 10 '13 at 17:07
Or space opera. – Meat Trademark Dec 10 '13 at 17:27

In your example you could imagine that the boots are pushing on the floor and the floor is rigid enough to absorb the momentum, and Dooko is trained enough to balance on his legs without apparent effort. When the difference in mass and momentum is much larger, it's a different matter of course, but I suspect that midichlorians are involved. That would, at least, give them a purpose :-)

Having said that, this is a typical issue in many action movies, where a bullet is able to push away the person hit, without a comparable recoil on the shooter. So SW is not much worse, in the department of the willing suspension of disbelief, than many other non SF movies.

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There's no reason to suggest that the force comes form a Jedi themselves, rather than being directed by them. If I push the pedal in my car to make it go forward, I don't need to actually exert enough effort to move the automobile. – DougM Dec 11 '13 at 3:00
When you push the pedal you are actually allowing for the inflow of fuel which will be burned and the resulting pressure on the piston will move forward the wheels while the exhaust gases are thrown away: that is you see conservation of momentum, without violation of locality. In the movie you don't see the "exhaust gases", as the OP put it "you don't see any wind". So you have to admit that the Force is pushing away Obi Wan while dissipating "somewhere" the momentum not in any place to be seen (so how is this vibration transmitted? My answer: oscillating midichlorians). :-) – Francesco Dec 11 '13 at 9:05
I have to add for completeness that we know for "sure" that the Force oscillates, transmitting "disturbances". – Francesco Dec 11 '13 at 9:07