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Frame dragging
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Rotating masses drag spacetime.
A rotating mass drags spacetime around with it (Lense–Thirring effect), measured by Gravity Probe B in Earth orbit at 39 milliarcseconds/year.
Near a Kerr black hole nothing can remain at rest.
Effect is tiny for Earth.
In more detail
Frame dragging is the twisting of spacetime around a rotating mass. A rotating body drags nearby spacetime with it, which can be measured by satellites.
Real-world uses
- The Gravity Probe B mission measured frame dragging around Earth.
- Frame dragging affects the orbits of satellites around rotating bodies.
- Physicists predict that a rotating black hole drags spacetime around it, which is tested by satellites near Earth.
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Frequently asked questions
How big is frame dragging for Earth?
Very small, which is why it took a sensitive mission to measure it.
Where else is it important?
Near rapidly spinning black holes, where its effects are large.
What is frame dragging?
The effect that a rotating mass drags the local spacetime around with it, so nearby objects are pulled into rotation.
Related topics in Relativity
Black hole event horizon · Hawking radiation · Gravitational waves detection · Light bending by the Sun · Cosmological redshift · Wormholes