Hot density rocks
From CERN article:
"There are many very dense and very hot questions to be addressed with the ion run..."
With the Large Hadron Collider's (LHC's) refit and restart accomplished, the records just keep tumbling. CERN has announced the highest-energy ion collision ever. The data generated by the experiment is going to take time and supercomputers to analyse, but CERN says the two lead ions slammed into each other at more than 1 Peta …
That sounds like a discussion of politics here in the States lately... "dense and hot".
Ok.. seriously question. Since they're generating "temperatures about a quarter of a million times those at the core of the sun.” and they want to go higher on the energy levels, how can they keep the temperature at the collision point from damaging the inside of the collider? I understand there's liquid hydrogen for cooling but even for a micro-second, that's a lot of energy to be dissipated.
We're talking pairs of atoms, not handfuls of the stuff, and probably not even nanoseconds of time.
Localised energy may be incredibly high, but it's localised to a very very tiny volume and lasts a very very short time.
The liquid helium cooling is so the superconducting magnets, well, you know... superconduct.
"how can they keep the temperature at the collision point from damaging the inside of the collider"
Note that 1 electron-volt equals 1.6x10^-19 joules. A single 1 peta-electron-volt (1x10^15 eV) blast amounts to about 1.6/10,000th of a Joule, and they're infrequent. If you manage to achieve 10,000 collisions per second, then the interior of the machine would have to deal with 1.6 Watts of heating. The massive vacuum casing and magnets probably won't notice 1.6 Watts.
However, the peta-volt collisions appear to be counted individually at this point, so you're probably not going to get full Watt-level heating.
From what I've read of the LHC configuration [but please bear in mind, it's 30 years since I studied physics to A-Level], there are a couple of answers to your question...
Firstly, the "ring" that is used to accelerate the particles [well, OK, in fact it is actually 2 rings, one on top of the other, and with the contained particles traveling in opposite directions] is super-cooled in order to allow the magnets that contain the particles to get benefits from super-conductivity [i.e. to maximise field strength]. This means that when the particles are "just circling" they are not, in fact, colliding with anything at all, just zipping along through a vacuum...
Secondly, when the particles are allowed to collide - and the computers that govern the ring control whether or not this happens - the collisions can only occur at the location of the various experiments [ATLAS, CMS] that are positioned around the ring itself.
Now for the tricky part...
If you take two identical cars and set each to travel at 30mph until they meet in a head-on collision, the result of the impact is that both cars should [all things being equal] stop dead on the spot of the collision, because the respective kinetic energy each car brings to the collision would be exactly cancelled out by the other vehicle. The resultant energy is released as heat, [infra-red] light, and sound [and the gasps of insurance under-writers]. Point being that the two cars stop, or, if they do continue to move, it is at a fraction of their original speed and with a fraction of their original energy...
So now lets go back to ATLAS and CMS... Inside the huge chambers that house these experimental sensors, the environment is set up so that the high energy particles travel through the matter of the sensor, leaving a wake of interactions [with the sensor] as they go. Each interaction essentially robs a bit more energy from the particle, until it decays naturally [which is the way these particles behave, given their latent instability].
OK, we got as far as slow-moving particles... Because they are moving much more slowly now, and because their lifespan can be measured in millionths, billionths or even trillions of a second, they literally don't have time to travel beyond the physical confines of the detector before they literally disappear through decay.
So that's why the LHC doesn't melt itself...
I'll say it again: I'm not a physicist and I've only got a basic understanding from reading reports and articles from science journals and tech news sites like this one. Your mileage may vary [YMMV].
“At that temperature, matter becomes a strange thing called a quark-gluon plasma, not seen in nature since the universe's age was measured in microseconds.”
Is that true? I can’t believe that it took a human-made collider on Earth to achieve what was impossible for the last 14 billion years.
Ultra high energy cosmic rays can exceed this energy level. The "Oh-My-God particle" had an energy of approximately 3x10^20 electron volts. However the energy released in a single collision of such a particle with a stationary proton or neutron is much lower at about 7.5x10^14 electron volts. An (exceedingly unlikely) head on collision of 2 such such particles would release more energy than could be produced in any man made accelerator (even one as big as the planet!!).
(For more information on the Oh-My-God particle see https://en.wikipedia.org/wiki/Oh-My-God_particle)
I am a little bit confused about that. The nuclear mass of the common lead isotope is 208, so wouldn't it be 416 nucleons colliding?
At the energies involved, the two nuclei look to one another like thin discs colliding face on, so I imagine it is possible that some of the nucleons just go straight through and out the other side and the figure of 208 is coincidental, but it seems oddly specific to the lead nucleus mass.
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"the Wikipedia article seems to suggest only protons are involved"
It's only the protons that are charged so it's those on which the accelerator works. The neutrons are just along for the ride.
A car analogy - it's only the tyre contact patch that touches the road so it's that that gets accelerated and the rest of the car is just along for the ride.
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Replying to myself, Chris Williams from the Reg has helpfully contacted me and as a result I now have the link to the CERN announcement.
The announcement is a bit badly worded, I think. It explains that the total energy is about a PeV (1045TeV), and that there are 208 nucleons in a lead nucleus. It then suddenly switches to writing about nucleon pair energies, which are roughly 1045/208 or about 5TeV, without explaining that each nucleon of each pair is from each of the colliding nuclei. It's easy to miss that it is 5TeV per pair and not per nucleon. The point is that the total collision energy is the sum of the energies of each nucleus, so they are accelerated to a "mere" 522.5TeV each.
So yes, there are 416 nucleons involved and the energy per nucleon is about 2.5GeV as I surmised.
Those of us in PETA NEVER harm animals. We raise them with tender loving care, then we kill them and eat them.
 That's "People Eating Tasty Animals", not the enviro-idiots "People Exterminating To Acquire"
 Seriously, look up PETA's record on euthanizing all the strays that get dumped on them by completely clueless idiots.
 Don't get me wrong ... I'm no fan of "no kill" shelters ... but the PETA folks make a profit off of the concept. Frankly, it's quite disgusting.
... the commentards would do well to understand the difference between "energy" and "heat".
Consider poaching fish in water at a simmer, and the same cut of fish in olive oil at the exact same temperature ... The oil variation takes much longer than the water. Why? Because the water contains more energy than the oil at that temperature.
"The oil variation takes much longer than the water. Why? Because the water contains more energy than the oil at that temperature."
While I'm being pernickety about basic physics, you're wrong. It has almost nothing to do with the specific heat. If olive oil takes longer it is because it is more viscous and so transfers heat from the heat source more slowly.
If you dropped the fish into two small containers at the same temperature with no external heat source the fish in the oil would take longer because there was less stored heat in the oil. But if both containers are kept at the same temperature the fish will cook at the same rate.
Who immerses fish in olive oil to cook it anyway?
"If olive oil takes longer it is because it is more viscous and so transfers heat from the heat source more slowly."
Viscosity has nothing to do with it. It takes more energy to heat a quart of water from room temperature to a simmer (say, roughly, 195F or 90.5C, depending on altitude) than it does to heat the olive oil to the same temperature over the same heat source. The simplest way to verify results is with a stop-watch and a thermometer. This is one of those things you can try at home.
Likewise, the water transmits that energy to the food faster. You can verify this with a stopwatch and a thermometer. Again, it's a simple experiment you can try at home.
You are correct, it's a basic physics thing. But I don't think you quite have a proper handle on it.
"Who immerses fish in olive oil to cook it anyway?"
People who know what food is for. Dazzles the mind, and boggles the senses.
Titles like "...fail to suck Earth into black hole..." are likely to be read by politicians, you know.
Funding Politician: So I see here the LHC failed to... something or other, I can't read that much in a day. Anyway, failure is grounds for cutting budget.
Scientist: Err, I think you'll find that we didn't do a bad thing...
FP: 'Failure' is the only way important word anyway. Now go & succeed at it or else.
Scientist: Damn you, El Reg...!
Dick Cheney, Lord of Darkness, is waiting at the bottom, biding his time and cackling furiously.
An ex-Labour politician, Simon Parkes, has claimed “psychopathic” world leaders, known as the “illuminati”, were planning on using CERN’s Large Hadron Collider (LHC) to open up a vortex allowing them to take control over the human population.
(I don't know how the above site looks w/o NoScript, so beware)
Nearly as hot as the filling of a pop-tart then.
Those bastards are no joke. I had a grade school acquaintance get a blister the size of a business card on the roof of his mouth from a Pop Tart. While I might've needed some hard personal lessons about sticking metallic objects into electrical outlets to learn that's a bad idea, I learned purely by observation not to take hearty bites of Pop Tarts (and Hot Pockets and their ilk) because of that kid's agony.
"I learned purely by observation not to take hearty bites of Pop Tarts (and Hot Pockets and their ilk) because of that kid's agony."
Come come, surely *anything* that resembles molten lava should make even the most numptified numpties dispense with bites and reset to nibble mode ...?
"Come come, surely *anything* that resembles molten lava should make even the most numptified numpties dispense with bites and reset to nibble mode ...?"
I'm not sure how to explain it, other than to note his name wasn't Shirley. He must've just gone in for a huge first bite.
The kid was ten years old at the time and in the gifted class of the school, so that's enough age, experience, and intelligence to be cautious with a freshly baked Pop Tart. I won't forget the dark red patch on the roof of his mouth where the blister had popped, though.
I thought the reason that they weren't going to suck the Earth into a black hole is that the energies of the collisions they bring about are lower than those which sometimes occur naturally because of cosmic rays! (But they need an expensive accelerator to have them happening when a scientist is watching to study and learn from the collisions.)
But now you're saying that it's creating something that hasn't been seen at all - which would include in cosmic ray events - since shortly after the Big Bang!
That's what could get them shut down!
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"Creating a sustained region where collisions are occurring thousands or millions of times a second could create torsional stress which combined with the rotational velocity of the Earth might be enough to tear the fabric of space-time "
Ref. ? ( I mean a proper, authoritative ref. not some loony website)
There has for many years been a debate as to why anything exist at all when during the Big Bang matters twin,'anti-matter' ought to have completely anihilated 'matter' completely.
I think that is absolutely WRONG,in that infinitely small duration of time, 'matter' did NOT exist,all that existed was ENERGY,for however brief an amount of time & because no matter existed neither did GRAVITY.
From that energy, E-MC2 began the process of forming matter beginning with Quark Gluons & onto formation of atoms in humongous quantities,so vast - dense,superhot, that in 300,000 years, a thermal cloud the size of the size of the Andromeda Galaxy had formed.
The thermal heat generated could only attempt to escape through inflationary expansion, that continues today.
As long as there are two-bodies under gravitational influence of each other,there will be heat & the prospects of every bit of matter reaching thermal equilibrium with it's background will take a very long time to be reached.
Even some 13.8 BILLION years after the Big Bang, the very atoms formed then(including the billions in each of us)are still around today & will be for evermore.
That is truly amazing,with no 'tooth fairy' in sight either.
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