http://news.bbc.co.uk/1/hi/sci/tech/4327161.stm
"CERN tunnel machine gets key part
The first of some 5,000 magnets that will bend particles at near light-speed around a huge tunnel under Switzerland and France has been lowered into place. "
"Scientists hope this will enable them to see new physics, and discover the sought-after Higgs boson, or "God particle", which explains why matter has mass.
Researchers may even find new dimensions and generate mini-black holes. "
I forget exactly which energy scales that you need to operate on to generate micro black holes, but it seems unlikely we'd be able to build anything like that any time soon.
And before anyone gets the idea: Micro black holes are not dangerous - black holes evaporate at a rate relative to the inverse fourth power of their radius (don't quote me on that, I may be misremembering), and small black holes will evaporate and disappear long before they have any chance to encounter any matter that they could use to grow.
Not dangerous, not dangerous... Yeah well do not put your arm near the micro black hole while it's not yet evaporated, I'd say. :) It would be hot with a capital H. Plus it's gonna end with a big bang so keep your distances. (This is all theorical, tho.)
http://news.bbc.co.uk/2/hi/science/nature/4357613.stm
> A fireball created in a US particle accelerator has the characteristics of a black hole, a physicist has said.
We may already have made them. I really hope this turns out to be real, because it would no doubt help the search for a theory of quantum gravity immensely.
...or rather, it seems the BBC story is just a little bit misleading, and what they're actually saying is that whatever was created is somehow symmetric to a black hole according to whichever crazy quantum theory they are working under. It's way beyond me.
I'm trying to get the complete article at
www.newscientist.com/article.ns?id=mg18524915.400
but I can't seem to manage to get subscribed...
>This fireball, which lasts just 10 million, billion, billionths of a second
what does that mean in numbers? 10^18?
copypaste using the institutional ip login:
Black hole-like phenomenon created by collider
* 19 March 2005
* From New Scientist Print Edition. Subscribe and get 4 free issues.
* Eugenie Samuel ReichAdvertising
A FIREBALL created in a particle accelerator bears a striking
similarity to a black hole. But don't panic: even if the controversial
claim is true, it is not the sort of black hole that would cause Earth
to disappear in a puff of radiation.
At the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National
Laboratory in Upton, New York, beams of gold nuclei travelling at
close to the speed of light are smashed into each other. The intense
heat of the collision breaks down the nuclei into quarks and gluons,
the most basic building blocks of all normal matter. These particles
form a ball of plasma about 300 million times hotter than the surface
of the sun (New Scientist, 16 October 2004, p 35).
The fireball, which lasts a mere 10-23 seconds, can be detected
because it absorbs jets of particles produced by the collision. But 10
times as many jets were being absorbed by the fireball as were
predicted by calculations using quantum chromodynamics (QCD), the
theory that describes quarks and the forces that hold them together.
But QCD calculations are notoriously hard, so physicist Horatiu
Nastase of Brown University in Providence, Rhode Island used a version
of string theory known as AdS to model events following the
collisions. He says that his calculations show that the core of the
fireball has the characteristics of a black hole. Nastase says that
this could explain why so few jets of matter are seen coming out of
the fireball. He thinks the particles are disappearing into the core
and reappearing as thermal radiation, just as matter falls into a
black hole and comes out as "Hawking" radiation. His calculation of
the temperature of this radiation matches the observed temperature of
the fireball - about 2 trillion kelvin (www.arxiv.org/hep-th/0501068).
However, at these energies and distances gravity is not the dominant
force in a black hole, so even if Nastase is right, it poses no
danger.
"Nastase's calculations using string theory show that the core of the
fireball has the characteristics of a black hole"
Ed Shuryak, a physicist at Stony Brook University in New York is not
convinced by Nastase's work. "It's very useful in the sense that it
will inspire thinking in that direction," he says. "It's going to be
another thing to see if it produces any fruit."
Other physicists say there are flaws in the calculations. For example,
Nastase assumes that the value of a constant that appears in his
equations is exactly 1, rather than calculating the value himself. He
admits that he is guessing and says, "In physics quite often these
dimensionless constants turn out to be 1."
Shuryak also points out that while the fireball cools rapidly to
around half its initial temperature, Nastase's calculations assume its
temperature is fixed. Shuryak is now working on his own AdS
calculations that will take this into account. "Any solution must
explain how the temperature evolves as a function of time," he says.
There is a precedent for the idea that AdS calculations will come up
with the right answer. In 1997 Juan Maldacena of the Institute for
Advanced Study in Princeton, New Jersey, suggested AdS is analogous to
a version of QCD. So if calculations in one theory become intractable,
it is possible to make progress by switching to the other theory. The
conjecture is well respected because it has led to several theoretical
breakthroughs.
String theory is often criticised for not making predictions that are
testable, so it is exciting that Nastase's theoretical work predicts
the outcome of an actual experiment, says Carlos Nunez, a string
theorist at MIT in Cambridge, Massachusetts. But given the assumptions Nastase made, Nunez thinks that the match
between the AdS calculations of the temperature of the fireball and
what is seen at the RHIC could be a coincidence. "I wouldn't say his
model is wrong, but it's clearly under construction," says Nunez.
From issue 2491 of New Scientist magazine, 19 March 2005, page 16
Printable version
Thanks.
Argh they don't say how the fireball ended up. According to theory a mini black hole should explode at the end of the evaporation.
The article doesn't even mention "dual black hole" which is the title of Nastase's paper. http://arxiv.org/abs/hep-th/0501068
Let's see the PDF... "rapidly decays through the emission of
pions= dual gravitons, almost in an explosion."
Almost... lol
> The article doesn't even mention "dual black hole" which is the title of Nastase's paper.
The term "dual" here does not mean "two", but instead means a certain kind of symmetry in the theory being used, or so I've been led to believe. Each particle is symmetric to some other kind of particle, and this referred to as being "dual to" the other particle.
> Nastase's calculations using string theory show that the core of the fireball has the characteristics of a black hole.
That's the layman's translation of saying that the fireball is a "dual black hole" - it is symmetric to, or "dual to", a black hole, just as pions are dual to gravitons.
Note that I know nothing of AdS theory, so I might be talking out of my ass here.
>symmetric to, or "dual to", a black hole, just as pions are dual to gravitons.
I don't get it - what's the definition of symmetry in quantum physics?
answers.com and wiki.com are either of no help, or I'm looking at the wrong places.
>wiki.com
oops I meant wikipedia.org, of course.
Thanks.
I still think that "dual black hole" is a bad name.
"Dual symmetry black hole" or something, would be less misleading.
It's specialist terminology, so it's not really meant to be easily understood in the first place. People tend to shorten things like this when the meaning is obvious from context, since you're talking to other people who understand the same theory. In this case, it's apparently caused quite a bit of confusion when people who don't know the terminology have tried to read the paper and/or abstract.
Learning Physics by reading essays or abstracts on Physics seems to be a bit like trying to learn Japanese by browsing Futaba.
Ah, then it's very easy.
"Nastase is DQN!101!!"