Yakk wrote:The claims that there is no way to bound it away from 100% efficiency seem wrong, as there is going to be an entropic cost to aiming at the target (picking that target, and not others, to apply your energy to), no? And that cost increases with the distance of the target (given a fixed size), as your aim has to be more precise?
Typically, the entropy cost of "setting up" a system is counted separately from the energy used within the system. The OP asks whether there is any intrinsic energy inefficiency proportional to distance when moving from the nonfictional realm of pushing on an object and the fictional realm of action at a distance. To be sure, the chosen telekinetic mechanism (whether it involves aiming or some sort of lossy particle beam or whatever) may indeed involve distance-dependent inefficiencies, and we've seen how the concept of moving something in a nonlinear direction will introduce torquing and thus decrease effective strength, but neither of those things are energy inefficiencies intrinsic to physics itself.
Depending on how the telekinesis works, my stick figure in the diagrams above could conceivably use a third object somewhere as a fulcrum or anchor of some kind and thus be able to exert greater sideways force than he otherwise would have been able to.
This cost (on first approximation) doesn't seem high, but it seems to be non-zero.
When the energy costs of an action can be made arbitrarily low by making the action arbitrarily slow, they can be dismissed for the purposes of evaluating the system itself.