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The largest jellyfish ever caught measured 2,3 m (7'6") across the bell with a tentacle of 36 m (120 ft) long. |
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Could black holes be portals to other universes?
Posted on Sunday, April 29, 2007 (CDT) by Thoth
 The objects scientists think are black holes could instead be wormholes leading to other universes, a new study says. If so, it would help resolve a quantum conundrum known as the black hole information paradox, but critics say it would also raise new problems, such as how the wormholes would form in the first place.
A black hole is an object with such a powerful gravitational field that nothing, not even light, can escape it if it strays within a boundary known as the event horizon. Einstein's theory of general relativity says black holes should form whenever matter is squeezed into a small enough space.
Though black holes are not seen directly, astronomers have identified many objects that appear to be black holes based on observations of how matter swirls around them.
But
physicists Thibault Damour of the Institut des Hautes Etudes
Scientifiques in Bures-sur-Yvette, France, and Sergey Solodukhin of
International University Bremen in Germany now say that these objects
could be structures called wormholes instead.
Wormholes are warps in the
fabric of space-time that connect one place to another. If you imagine
the universe as a two-dimensional sheet, you can picture a wormhole as
a "throat" connecting our sheet to another one. In this scenario, the
other sheet could be a universe of its own, with its own stars,
galaxies and planets.
Damour and Solodukhin
studied what such a wormhole might look like, and were surprised to
discover that it would mimic a black hole so well that it would be
virtually impossible to tell the difference.
Hawking radiation
Matter would swirl around a
wormhole in the same way as for a black hole, since both objects
distort the space around them in the same way.
One might hope to
distinguish the two by something called Hawking radiation, an emission
of particles and light which should only come from black holes and
would have a characteristic energy spectrum. But this radiation is so
weak that it would be completely swamped by other sources, such as the
background glow of microwaves left over from the big bang, making it
unobservable in practice.
Another difference one
might hope to exploit is that unlike black holes, wormholes have no
event horizon. This means that things could go in a wormhole and come
back out again. In fact, theorists say one variety of wormhole wraps
back onto itself, so that it leads not to another universe, but back to
its own entrance.
Daring plunge
But this does not provide a
foolproof test either. Depending on the detailed shape of the wormhole,
it could take billions of years or more for things to pop back out
after falling in. With the right shape, even the oldest wormholes in
our universe would not have had time to spit anything back out yet.
It seems the only way to
decide the issue for sure with astronomical black holes is to make a
daring plunge inside. That would be a dangerous gamble, because if it
is a black hole, the incredibly strong gravitational field inside would
tear apart every atom in your body. Even if it turns out to be a
wormhole, the forces inside could still be deadly.
Assuming you could survive,
and the wormhole was not symmetric, you might find yourself in another
universe on the other side. Without further intervention, the wormhole
would tend to suck you back in and carry you back to the opening in
your universe.
Yo-yo motion
"The spaceship would do
this yo-yo motion," Damour told New Scientist. "[But] if you use your
fuel, then you can escape from the attracting power of the wormhole and
explore" the space on the other side, he says.
But a friend in either
universe might have to wait billions of years to hear back from you,
since the transit time could be excruciatingly long.
Such a delay would make
meaningful communication with anyone on the other side impossible. But
the delay gets smaller with smaller wormholes. If a microscopic
wormhole could be found or constructed, the delay across it could be as
short as a few seconds, Solodukhin says, potentially making two-way
communication possible.
Stephen Hsu of the
University of Oregon in Eugene, US, who has studied the formation of
black holes and the properties of wormholes, says he agrees that
distinguishing between the two types of object with observations is
practically impossible, at least with current technology.
Exotic matter
"The most important
property of a black hole – that there is a 'point of no return' for an
object falling in – is not something we can test at the moment," he
told New Scientist.
Still, he says the objects
out there suspected to be black holes probably really are black holes
rather than wormholes. There are plausible scenarios for forming black
holes, he says, such as the collapse of a massive star, but it is not
clear how you would form a wormhole.
"Wormholes that might be
confused with a macroscopic black hole require some kind of exotic
matter to stabilise them, and it is not known whether such exotic
matter exists," he says.
Solodukhin says that a
wormhole might form in much the same way that black holes form, such as
from a collapsing star. Physicists normally expect in these situations
that a black hole would be produced, but Solodukhin says that quantum
effects may stop the collapse just short of producing a black hole,
leading to a wormhole instead.
Microscopic black holes
He says this mechanism
might be inevitable in a more complete picture of physics that unites
gravity and quantum mechanics – a longstanding goal of physics. If he
is right, then wherever we used to expect black holes to form,
wormholes would form instead.
And there might be a way to
test the conjecture. Some physicists say that future particle
accelerator experiments could produce microscopic black holes.
Such tiny black holes would
emit measurable amounts of Hawking radiation, proving that they are
black holes rather than wormholes. But if Solodukhin is right, and
microscopic wormholes are formed instead, no such radiation would be
expected. "In that case, you would actually see if it is a black hole
or a wormhole," he says.
An added benefit of
wormholes is that they could resolve the so-called black hole
information paradox. The only way anything can exit a black hole is in
the form of Hawking radiation, but it is not clear how the radiation
carries information about the original object that was swallowed. This
scrambling effect conflicts with quantum mechanics, which forbids such
erasing of information.
"Theoretically, wormholes
are much better than black holes because all these problems with
information loss don't exist in this case," Solodukhin says. Since
wormholes have no event horizons, things are free to leave without
first being converted into Hawking radiation, so there is no problem
with lost information.
Copyright: New Scientist
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Re: Could black holes be portals to other universes?
by zoarian on Monday, April 30, 2007 (CDT)
(User Info | Send a Message) http://fairiejewelry.com | | One night while meditating i was given, or say downloaded, a beautiful revelation in regards to the multiverse and included in this revelation was that the black holes are in fact entrances/portals to other universes. |
Re: Could black holes be portals to other universes? (Score: 1)
by on Thursday, May 03, 2007 (CDT)
(User Info | Send a Message) | Amazing how little there is to learn for a lay person who has read Carl Sagan's Cosmos. Then Hawking's Brief History of Time. Between black holes and worm holes - the difference seem to be the same as what Carl Sagan's book postulated. Unknown. He had postulated the possibility of Black holes being the passage as worm holes to another or another side of the universe. Quasars were then postulated as the possible outcome or the other end of a black hole.
As postulations, not much seems to have improved ever since Sagan's book in the 1970's!
The problem being of the law that matter can neither be created nor destroyed, at least as far as human efforts are concerned...
(Something that the Indian Left and religious fanatics seem to have taken to their heart, in their own twisted logic, and turned that into a philosophy of nihilism, minus the contemplation, however flawed, that leads to what would be nihilism! )
But the thought is exciting - after having survived the event horizon of the two categories mentioned - of actually jumping straight into a black hole and jumping back...to tell the story to an earthling! |
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