- 4400 - BLACKHOLES -
stretch the mind? - Is there anything stranger in the universe
than black holes? These bizarre, gravitational monstrosities don't only warp
space and time; just thinking about them stretches and bends people's
imaginations .
------------------------- 4400 -
BLACKHOLES - stretch the mind?
-
Along with all the mind-boggling qualities you
might have heard of their prodigious mass, their incredibly small size, black
holes have a ton of even more outlandish properties that are less well known.
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- Black holes might have hair. In the 1960s, physicist John Wheeler
suggested that black holes "have no hair," meaning that each
particular cosmic object could only be distinguished from its brethren by its
spin, angular momentum and mass. Any other differentiating information about a
black hole is considered "hair," and is thought to disappear behind a
black hole's impenetrable event horizon, a boundary around the black hole
beyond which nothing, including light, can escape.
-
- But in 2016 famed physicist Stephen Hawking
proposed that black holes actually sport an opulent hairdo made of ghostly,
zero-energy particles, and that this agglomeration contains information about
material the black hole has consumed. This hypothesis has not been proven, but
could help solve a longstanding paradox about what happens to gas and dust that
has fallen into a black hole.
-
- Nothing is supposed to be able to escape a
black hole's powerful gravitational grip. But that only applies to material
that has gotten extremely close to the hole's edge. Many black holes are, in
fact, surrounded by streams of gas and dust, which circle around the hole, like
water going down a drain.
-
- Friction in this material generates heat,
which creates churning, storm-like structures in the gas and dust. Recent
observations suggest that this motion also produces arching rings that surround
inner columns of matter, which shoots straight into the air, strongly
resembling fountains.
-
- Quantum mechanics provides another way for
particles to escape a black hole. According to theory, pairs of subatomic
particles are constantly blinking in and out of existence around a black hole's
event horizon. Every so often, the configuration is aligned in just the right
way to cause one of the partners to fall into the black hole.
-
- The particle's identical associate is then
propelled away at extremely high speed, robbing the black hole of a tiny bit of
energy. This produces what's known as “Hawking radiation”, after Stephen
Hawking, who discovered the phenomenon. Because energy equals mass, this
process actually can cause a black hole to shrink and eventually evaporate away
over long periods of time.
-
- One of the problems with Hawking radiation
is that it causes conundrums for physicists. The subatomic particles produced
by this radiation are entangled, meaning that what happens to one is
immediately felt by the other. So what does the partner that didn't fall into
the black hole feel as its associate gets crushed into an infinitely dense
point? Nobody knows.
-
- One theory holds that the black hole severs
the particles' entanglement, an outcome that according to the laws of quantum
mechanics would produce an insane amount of energy. That, in turn, would mean
that all black holes are surrounded by roiling walls of fire.
-
- It's hard to square black holes' crushing
mass with the laws of quantum mechanics, which hold that information about
particles can never be destroyed. But material that slips beyond a black hole's
edge should become forever lost to the universe. This conundrum is known as the
“black hole information paradox”; a resolution has eluded scientists to date.-
-
- Shortly after the Big Bang, the universe
should have produced a multitude of tiny black holes. Because these features
would be massive objects that give off no light, some physicists have
conjectured that these primordial black holes could account for dark matter,
that mysterious material that the vast majority of matter in the cosmos is made
of.
-
- But the idea is controversial, given that
data from the Laser Interferometer Gravitational-Wave Observatory (LIGO) has
ruled out a universe filled with many minuscule black holes. Perhaps
medium-size black holes might still be lurking out there, though observations
suggest they would only make up, at most, 1% to 10% of dark matter.
-
- Black holes run into the problem of
infinity. A black hole's mass is
crushed to an infinitely dense point that's infinitely small in size.
Physically, this doesn't make any sense, so researchers have searched for
alternative frameworks to get a handle on black holes.
-
- One proposal is known as “quantum loop
gravity”, which suggests that the fabric of space-time is curved very strongly
near the center of the black hole. This would result in part of the hole
extending into the future, meaning that matter getting sucked into it would
time travel forward. So far, this mind-expanding idea remains theoretical.
-
- One highly-controversial observation
suggests that our universe is a latecomer. Earlier universes might have existed
before ours, and would have contained black holes. Prominent Oxford University
mathematical physicist Roger Penrose has argued that cosmic background
radiation, an energetic relic from the Big Bang, contains imprints of these
black holes from before time.
-
- Physicists are set to release the
first-ever image of a black hole. This supermassive beast lurks at the heart of
our Milky Way galaxy; capturing a photo of it has been the aim of the Event
Horizon Telescope. This instrument is actually a global network of radio
telescopes all over the Earth, which have combined their powers to zoom in
closer to the galactic center than ever before.
-
- The telescope should be able to spot the
black hole's shadow across its material surrounding, and images are expected on
April 10, 2024. Let's hope this news
doesn't fall into a blackhole!
-
-
March 23, 2024 BLACKHOLES -
stretch the mind? 4400
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--------------------- --- Saturday, March 23,
2024
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