http://groups.csail.mit.edu/mac/users/wisdom/swimming.pdf
There is a good discussion here:
https://physics.stackexchange.com/questions/886/swimming-in-spacetime-apparent-conserved-quantity-violation
My question: Is it possible to design a quasi-rigid body that could be used to escape Earth surface?
Many thanks!
Citation: "For a quasi-rigid body to swim on a curved manifold, it must undergo changes in its shape. For such a change to result in a net rotation or translation of the body on the manifold, the shape changes must go through a nontrivial cycle of deformation.
A simple quasi-rigid body that satisfies these requirements is a body consisting of one mass point with mass m0 connected to two other mass points, each with mass m1, by geodesic struts of given length separated by a given angle. The body can be deformed by changing the length of the struts or the angle between them;
... If the axis of the body is oriented radially away from the central mass, then the symmetry of the Schwarzschild geometry and the threefold symmetry of the swimmer guarantee that any translation due to cyclic deformation will occur only in the radial direction. The problem is, then, to compute the radial component of the deformation field strength.
... The curvature of spacetime is very slight, so the ability to swim in spacetime is unlikely to lead to new propulsion devices. For a meter-sized object performing meter-sized deformations at the surface of the Earth, the displacement is of order 10⁻23 meters."