beecee Posted May 25, 2018 Share Posted May 25, 2018 https://phys.org/news/2018-05-particle-rotating-spacetime.html How a particle may stand still in rotating spacetime When a massive astrophysical object, such as a boson star or black hole, rotates, it can cause the surrounding spacetime to rotate along with it due to the effect of frame dragging. In a new paper, physicists have shown that a particle with just the right properties may stand perfectly still in a rotating spacetime if it occupies a "static orbit"—a ring of points located a critical distance from the center of the rotating spacetime. The physicists, Lucas G. Collodel, Burkhard Kleihaus, and Jutta Kunz, at the University of Oldenburg in Germany, have published a paper in which they propose the existence of static orbits in rotating spacetimes in a recent issue of Physical Review Letters. "Our work presents with extreme simplicity a long-ignored feature of certain spacetimes that is quite counterintuitive," Collodel told Phys.org. "General relativity has been around for a bit more than a hundred years now and it never ceases to amaze, and exploring the ways that different distributions of energy can warp the geometry of spacetime in a non-trivial way is key to a deeper understanding." Read more at: https://phys.org/news/2018-05-particle-rotating-spacetime.html#jCp:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: the paper: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.201103 Static Orbits in Rotating Spacetimes: ABSTRACT: We show that under certain conditions an axisymmetric rotating spacetime contains a ring of points in the equatorial plane, where a particle at rest with respect to an asymptotic static observer remains at rest in a static orbit. We illustrate the emergence of such orbits for boson stars. Further examples are wormholes, hairy black holes, and Kerr-Newman solutions. Link to comment Share on other sites More sharing options...
studiot Posted May 26, 2018 Share Posted May 26, 2018 The idea sounds like a development of the 'stationary' nature of the contact point of a bicycle wheel with the ground. Link to comment Share on other sites More sharing options...
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