There is, however, also the chance that both possibilities are true — that there are instances
of black holes spinning slowly in the field and instances
of black holes spinning rapidly in a dense environment.
In their latest finds, physicists with the Laser Interferometer Gravitational - Wave Observatory spotted the merger
of black holes spinning in different orientations, as shown in this artist's conception.
The highest - energy light arises from the center of a crescent - shaped region on the side
of the black hole spinning toward us.
Not exact matches
This produced a
spinning black hole 21 times the mass
of the sun.
The Advanced Laser Interferometer Gravitational - Wave Observatory's detection
of spacetime ripples from two merging
black holes on December 26, 2015, indicated that one
black hole was
spinning like a tilted top as it orbited with its companion (SN: 7/9/16, p. 8).
Study co-author Andrew Blain
of the University
of Leicester says that a slow
spin may be how this
black hole has sustained its binge, which he calls the equivalent
of «winning a hot - dog - eating contest lasting hundreds
of millions
of years.»
Study co-author Andrew Blain
of the University
of Leicester says that a slow
spin may be how this
black hole has sustained its binge, which he calls the equivalent
of «winning a hot dog — eating contest lasting hundreds
of millions
of years.»
But a photon with a very tiny «in between» mass can enter into an orbit
of the
spinning black hole and steal some
of its angular momentum.
Computer simulations suggest that when two
black holes spiral towards each other on a collision course, much
of the gas and dust in the
spinning accretion disc surrounding each
of them is ripped away by the gravity
of the other.
Cardoso and colleagues calculated how long photons
of given masses would take to sap a
black hole's
spin.
Physicists concluded that the first detected gravitational waves, in September 2015, were produced during the final fraction
of a second
of the merger
of two
black holes to produce a single, more massive
spinning black hole.
Physicists have described how observations
of gravitational waves limit the possible explanations for the formation
of black holes outside
of our galaxy; either they are
spinning more slowly than
black holes in our own galaxy or they
spin rapidly but are «tumbled around» with
spins randomly oriented to their orbit.
The study was motivated by recent groundbreaking simulations
of mergers between
black holes of different masses or
spin orientations.
The age
of the oldest
spinning black holes effectively puts an upper limit on the photon's mass.
For a rotating
black hole, the
black hole itself is probably a ring
of spinning neutrons, which does not collapse because
of centrifugal forces.
In 1963 Roy Kerr, a mathematician, found that a
spinning black hole collapses into a ring
of compressed matter, not a dot.
These are though to emanate from the
spin axis
of a
black hole.
According to their model, an incoming
black hole with at least 20 %
of the mass
of its partner will knock the main
black hole off kilter, no matter how rapidly it
spins.
Now Enrico Barausse, also at the University
of Maryland in College Park, and his colleagues reckon that such incoming particles needn't strip
spinning black holes.
Its twin detectors and companion supercomputers can pick apart the strength and frequency
of gravitational waves to learn a
black hole's mass,
spin and location.
But in 2009, physicists Ted Jacobson and Thomas Sotiriou at the University
of Maryland at College Park calculated that, under some circumstances, an incoming particle might cause a
spinning black hole to rotate so fast that this horizon is destroyed, allowing light to escape.
But if the
black holes instead find one another in the chaos
of a star cluster, they could
spin any which way.
Most astrophysicists think that gamma ray bursts, fantastically energetic flares from deep space, stream from new
black holes that form when the cores
of massive
spinning stars collapse to trigger supernovas.
They find that a
spinning naked singularity turns out to be a strong gravitational lens, magnifying the light from background stars more than an ordinary
black hole and producing a distinctive pattern
of images.
«Remarkably, we could also infer that at least one
of the two
black holes in the binary was
spinning.»
Merritt calculated the effect
of such a merger on the
spin of the combined
black hole.
The accuracy
of this assertion might become clearer in a few years, as various groups are running computer simulations to calculate the self - force
of particles orbiting
spinning black holes, says Barausse.
Likewise, if
black holes act like information mirrors, as Hayden and Preskill suggested, a particle falling into a
black hole would be followed by an antiparticle coming out — a partner with the opposite electric charge — which would carry the information contained in the
spin of the original particle.
This head -
spinning idea is one cosmologist's conclusion based on a modification
of Einstein's equations
of general relativity that changes our picture
of what happens at the core
of a
black hole.
For example,
spin may cause some
black holes to fire off violent jets
of matter.
New research reveals the dynamics
of the
spinning disks
of gas that surround young stars and gargantuan
black holes
Maity was an author
of the article, «
Black hole spin dependence
of general relativistic multi-transonic accretion close to the horizon,» which was published online last December in the journal New Astronomy and in print in the journal's May issue.
One
of the weirdest implications
of Einstein's general relativity theory is that as a
black hole spins, it pulls space - time along.
Observations
of the galaxy MCG -6-30-15 suggest that the
spinning of its central
black hole is producing power just like an electric generator.
Once matter is pulled toward the
black hole, it rotates around the edge and
spins off some
of its angular momentum before it falls in.
Stars also
spin, and when a large one collapses, the resulting
black hole must
spin even faster, since the same amount
of angular momentum is stuffed into a much smaller amount
of space.
Like bald pates,
black holes of similar masses and
spins then have no details — no «hair» — to distinguish them, as American theorist John Archibald Wheeler quipped.
«It's very tricky telling what's the feature and what's the continuum,» says Julian Krolik
of Johns Hopkins University, one
of the theorists now trying to figure out how magnetic fields could convert a
black hole's
spin energy into light.
That configuration would help it pinpoint the sources
of gravitational waves on the sky and allow it to see the longer - wavelength ripples from a wider range
of sources including binary white dwarfs, slower -
spinning pulsars and intermediate - mass
black holes weighing hundreds or thousands
of suns.
So, if Alice measures the
black hole's
spin before and after dropping the qubit, the change in the
spin is analogous to a bit
of classical information transmitted by Bob from within the
black hole to Alice outside.
Just measure the tiny change in the
spin of a
black hole.
By taking the change in the
black hole's
spin, and her half
of the Hawking radiation that is emitted after she drops the qubit, Alice can use the rules
of quantum teleportation to work out the
spin of the qubit she dropped into the
black hole — and hence retrieve information from beyond the
black hole's event horizon.
This time, the subtle tremor
of spacetime that signaled the merger also revealed a key feature
of the
black holes: their
spins, which were out
of kilter.
Around
spinning black holes, however, frame dragging could be hugely important: By whipping magnetic field lines through the electrically charged gas around the
holes, it could convert them into electromagnetic generators, which would explain how they spew jets
of energetic particles millions
of light - years into space.
«If the
black holes were not
spinning in the same direction as the orbit, that would probably be a pretty good indicator
of the dynamical formation channel,» Rodriguez says.
Still, the basic picture — a fierce corkscrew
of magnetized plasma unleashed by a frantically
spinning black hole — is valuable for quasar researchers, says astrophysicist Ramesh Narayan
of the Harvard - Smithsonian Center for Astrophysics in Cambridge.
Gravity distorts both aspects
of space - time, and any dynamic event — the gentle
spinning of a planet or the violent colliding
of two
black holes — sends out ripples
of gravitational waves.
LIGO researchers found that the
black hole spins were not aligned, and that there's an 80 % probability that at least one
of them
spun in generally the opposite sense
of the orbital motion.
The early 1970s were the «heroic age»
of relativity research — theorists had proved that if Einstein was right,
black holes weren't infinitely diverse but standardised objects, characterised just as surely as any elementary particle by mass and
spin.
The concept is a variant
of the Penrose process, first identified in 1969 by British astrophysicist Sir Roger Penrose as a mechanism for extracting energy from a
spinning black hole.