How Black Holes Feed

Black holes not only attract objects with gravity, as all massive objects do, but also seem to "rob" them of their angular momentum. Recent findings support a thirty-year-old hypothesis that this is caused by magnetic fields generated by the black holes themselves, rather than alternative theories.

Without angular momentum, the Earth would fall into the sun rather than revolve around it. The matter within a black hole's "accretion disk" loses angular momentum and, as a result, the matter falls into the black hole, to be "consumed" by it.

While magnetic fields have long been a major hypothesis of how this angular momentum was lost, alternate explanations were also plausible. The two most reasonable alternatives are inconsistent with recent findings from the NASA Chadra X-ray Observatory, while the magnetic field hypothesis is still consistent. Though this does not preclude a new, alternate hypothesis, it lends great support to the magnetic field explanation.

Related Articles:

• Science: "A Good Belch Helps Black Holes Feed"
• New Scientist: "Magnetic fields snare black holes' food"
• Nature: "The magnetic nature of disk accretion onto black holes" (subscription required)

Image: Artistic rendering of a black hole provided by NASA.