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Inertia forms the basis of Newtonian physics,but nothing really explains it.I know that it is generally accepted in classical physics,but can it's origin be explained?Maybe be relativity or quantum mechanics?


marked as duplicate by stafusa, John Rennie, Qmechanic Sep 26 '17 at 5:51

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I am not sure about explanation but It can be understood via GR. "Mass curves space".

When the mass curves space, it creates a dip in space around it. And that dip makes a force necessary to move the body.

Changing speed, or direction works the same way, you need a force to act against that state of the dip to change it.

There does not have to be any other mass around. Mass of any body, itself creates that dip of inertia and that is why more the mass, bigger the dip, harder to change the state of the dip, whether moving, or at rest.

  • $\begingroup$ does the state of the dip change for an object in motion? $\endgroup$ – michael Nov 28 '17 at 11:38
  • $\begingroup$ @m.r.: Obviously, it changes. At relativistic speeds the dip would become deeper and deeper requiring more and more energy for change in state. Note that this answer is an attempt to understand inertia, and likely is not a mainstream answer. $\endgroup$ – kpv Nov 29 '17 at 1:20
  • $\begingroup$ is this a theory or has it been proven by experiments? $\endgroup$ – michael Nov 29 '17 at 6:00
  • $\begingroup$ @m.r.: The part "requiring more and more energy for change in state at relativistic speeds" is experimentally proven in particle accelerators all the time. However, no one is able to see the dip itself, same way as no one has been able to see the curving of space. $\endgroup$ – kpv Nov 29 '17 at 7:06
  • $\begingroup$ isn't the part "requiring more and more energy for change in state.." just the definition of inertia? thnx $\endgroup$ – michael Nov 29 '17 at 11:23

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