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Oral Ideas

by bayan
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bayan
#1
Mar22-05, 05:54 AM
P: 202
Hello. I will be doing an oral presentation for my English SAC. I origionaly wanted to talk about space-time then I changed it to Singularity because I only have about 10 mins to talk and I dont belive that I can scratch the surface in 10 mins.

About singularity I know only a little bit(and that is how it is formed and some of its typical behavours) but I still have to do some research.

I was woundering if you could sugest some tpics that I could talk about.

I have to do this oral presentation on 30th of March 2005 So I still have abit of time.

Any sugestion is apriciated:)
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Mean-Hippy
#2
Mar22-05, 06:00 PM
P: 24
I heard ( or read sumwhere ) that the RHIC at Brookhaven attained (somewhat anyway) that long saught-after goal of creating micro-black holes in a particle accelarator . Prophets of doom around the world are sadened to realise that, he! the world did not go down the drain after all. That can be interesting I guess for a conclusion.
Ha.. theres a link

http://www.bnl.gov/rhic/black_holes.htm
marcus
#3
Mar22-05, 08:19 PM
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hello Meanhippy, and bayan,

I want to stash some links from this page that meanhippy flagged
I am not sure what to think about this but it seems potentially interesting.

http://www.bnl.gov/rhic/black_holes_kharzeev.htm

here is Meanhippy original link:
http://www.bnl.gov/rhic/black_holes.htm

"Horatiu Nastase, a member of the high-energy physics theory group at Brown University, has written a paper, posted on the preprint website arxiv.org, in which he claims that collisions at Brookhaven’s Relativistic Heavy Ion Collider (RHIC) produce the analog of a black hole..."

the way I read it they are not talking about a black hole at all! they are talking about Unruh radiation which is ANALOGOUS to hawking radiation.
It is just as interesting and Bill Unruh at UBC Vancouver discovered it right around the same time as Hawking discovered the theoretical production of blackhole radiation.

Unruh radiation comes from acceleration and the temperature formula is VERY SIMILAR to the hawking temperature formula

but lets not jump to conclusions, lets look at Horatiu Nastase paper itself and see what he really said

http://arxiv.org/abs/hep-th/0501068
The RHIC fireball as a dual black hole
Horatiu Nastase
10 pages, latex, references added, typos corrected, comments on RHIC experimental observations added

"We argue that the fireball observed at RHIC is (the analog of) a dual black hole. In previous works, we have argued that the large $s$ behaviour of the total QCD cross section is due to production of dual black holes, and that in the QCD effective field theory it corresponds to a nonlinear soliton of the pion field. Now we argue that the RHIC fireball is this soliton. We calculate the soliton (black hole) temperature, and get $T=4a <m_{\pi}>/\pi$, with $a$ a nonperturbative constant. For $a=1$, we get $175.76 MeV$, compared to the experimental value of the fireball ``freeze-out'' of about $176 MeV$. The observed $\eta/ s$ for the fireball is close to the dual value of $1/4\pi$. The "Color Glass Condensate'' (CGC) state at the core of the fireball is the pion field soliton, dual to the interior of the black hole. The main interaction between particles in the CGC is a Coulomb potential, due to short range pion exchange, dual to gravitational interaction inside the black hole, deconfining quarks and gluons. Thus RHIC is in a certain sense a string theory testing machine, analyzing the formation and decay of dual black holes, and giving information about the black hole interior."

I see he posted it at arxiv in january and then did a lot of revision and reposted it on 16 February 2005.

From some of the comment I take it that the acceleration we are talking about is going from the speed of light down to zero speed in about E-23 seconds.

in natural units this would be an acceleration of about E-19
have to go, back later to continue

marcus
#4
Mar22-05, 08:33 PM
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Oral Ideas

I may have to revise these numbers
but from what Kharzeev said about stopping from the speed of light in E-23 second that translates to E-19 accleration units (natural) and
the Unruh temperature formula is simply

[tex]T_\text{Unruh} = \frac{a}{2\pi}[/tex]

since LaTex sometimes doesnt work I will rewrite that as

Unruh temperature = acceleration/2pi

OK and the acceleration is E-19, so divide by 2pi and you get roughly E-20

jeez that is hot, I cant believe this, the temperature of the sunsurface is 2E-28
(a 100watt lightbulb tungsten filament is E-28, the sun is twice as hot as that)

so we are talking something that is 100 million times hotter than the surface of the sun

or as rough order of magnitude, 100 million electron volts.
there could be a mistake. lets look back at Khazreev comment
=========
No I have not made a mistake, I get essentially the same estimate as Khazreev
He says 200 million electron volts but i was being conservative and only looking for order of magnitude, so 100 million eevee is OK

"quarks and gluons is decelerated from the velocity of light down to zero velocity in a very short distance, about 0.2 femtometers. This deceleration thus must be accompanied by a burst of a hot thermal radiation with a temperature about 200 million electron-volts (MeV)..."
bayan
#5
Mar23-05, 04:12 AM
P: 202
What exactly is RHIC? I tried reading the pages and I didn't quiet understand:(


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