LHC: Collisions!

miles01110

macrumors Core
Original poster
Jul 24, 2006
19,264
30
The Ivory Tower (I'm not coming down)
http://www.nytimes.com/2010/03/31/science/31collider.html?hp (among others)

After 16 years and $10 billion — and a long morning of electrical groaning and sweating — there was joy in the meadows and tunnels of the Swiss-French countryside Tuesday: the world’s biggest physics machine, the Large Hadron Collider, finally began to collide subatomic particles.

Following two false starts due to electrical failures, protons whipped to more than 99 percent of the speed of light and to energy levels of 3.5 trillion electron volts apiece around a 17-mile underground magnetic racetrack outside of Geneva a little after 1 p.m. local time. They crashed together inside apartment-building sized detectors designed to capture every evanescent flash and fragment from microscopic fireballs thought to hold insights into the beginning of the world.
...and yet we're all still here and not at the center of a black hole. Great job maintaining your grip on reality, science!
 

SpookTheHamster

macrumors 65816
Nov 7, 2004
1,489
0
London
He's good when he talks about more complicated things. The BBC programme looks very pretty but is massively dumbed down.

I can't imagine how much data there must be to look through now.
 

iBlue

macrumors Core
Mar 17, 2005
19,174
15
London, England
He's good when he talks about more complicated things. The BBC programme looks very pretty but is massively dumbed down.
Definitely but I think that's the point. To make it all less daunting and scary for the average person out there but still keep it interesting enough. It's like a gateway drug to proper astrophysics!

(for anyone not sure what we're on about, here's a link but if you're outside the UK, the video won't work)
 

bartelby

macrumors Core
Jun 16, 2004
19,794
4
:D Aww, I love him! He explains vastly complicated topics in the most eloquent, bite-sized and understandable way. I like that he tries to make science less intimidating.
Yeah, just not so sure about him having to travel around the world to do it...
 

pooky

macrumors 6502
Jun 2, 2003
356
1
Incredible. I wonder how many other civilizations across the universe have done this before.
That should be easy to figure out. Just count the number of black holes that are approximately Earth-sized. :)
 

Submerged

macrumors newbie
Sep 30, 2003
7
0
ONtario
That should be easy to figure out. Just count the number of black holes that are approximately Earth-sized. :)
ha!!! But you mean, would have been earth sized :p since the event horizon of the hole would be approx. 9mm...try finding that in space. Reassuring, isn't it..
 

obeygiant

macrumors 601
Jan 14, 2002
4,003
3,776
totally cool
Particle physicists had been waiting for this day for more than two decades. 26 years after the LHC program began, conducted its first successful particle collisions . “It’s a great day to be a particle physicist,” said CERN Director General Rolf Heuer in a stement. “A lot of people have waited a long time for this moment, but their patience and dedication is starting to pay dividends.”
“With these record-shattering collision energies, the LHC experiments are propelled into a vast region to explore, and the hunt begins for dark matter, new forces, new dimensions and the Higgs boson,” said Fabiola Gianotti, spokesman for the LHC leading Atlas experiment. “The fact that the experiments have published papers already on the basis of last year’s data bodes very well for this first physics run.”
So, how much is 7 TeV, which is calculated by the combined energy of 3.5 TeV for the proton and anti-proton beam? 1 eV is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt. In plain numbers, 1 eV equals 1.602176487(40)×10−19 Joules. In comparison, a single molecule floating in air has the energy of 0.04 eV.
Apply these energy levels to particle beams, however, and you see the enormous dimensions of the LHC. To get the LHC to its maximum collision energy of 14 TeV, particle beams are travelling in bunches of 3000 or about 1 billion particles at a speed of 670,616,429 mph – or about 99.9% of the speed of light. The beam will travel through the 27 km (17 mile) LHC ring structure consisting of a pipe that runs through 1746 magnets (1232 dipoles and 514 quadrupoles, located 150 – 450 ft below the surface) 11,745 times per second. The energy level of each beam at 7 TeV is comparable to an average car that is travelling at 1000 mph. If you intended to build your own LHC, you would need 2.3 trillion flat 3 volt batteries to achieve the same particle beam energy level.
In fact, the energy created is difficult to understand and to control. When I visited the Tevatron in August 2007, which has been conducting particle collisions outside Batavia, IL at energy levels of close to 1.8 TeV, the system had just recovered from a beam loss, which saw a 0.98 TeV particle beam burn through 5 ft of solid steel within 16 ns. In the LHC, collisions are believed to create conditions that are more than 100,000 times hotter than the heart of the Sun.
Physicists hope that this will be enough to melt protons and neutrons to freeing the quarks from their bonds with gluons. In theory, the result would be a state of matter called quark-gluon plasma, which is believed to have existed just after the Big Bang when the Universe. Ultimately, scientists hope that the experiments will shake out the Higgs Boson, which is the only standard model particle that has not been observed yet. An experimental detection of the Higgs boson is likely to lead to the explanation of the origin of mass in the universe.
The LHC runs six detector experiments, including ATLAS, which chases the Higgs Boson; ALICE plans to study the quark-gluon plasma; CMS creates a magnetic field of 4 teslas, about 100 000 times that of the Earth; LHCb aims to explain why we live in a Universe that appears to be composed almost entirely of matter, but no antimatter by investigating the slight differences between matter and antimatter by studying a type of particle called the ‘beauty quark’, or ‘b quark’.
In the past, the LHC has fueled fears on uncontrollable chain reactions that turn the collider into a ticking time bomb and threaten the existence of earth. For example, some speculated that the collider could produce dangerous cosmic rays, black holes, strangelets, vacuum bubbles and magnetic monopoles.
However, the LHC team dismissed all concerns, stating that nature is consistently creating cosmic rays on earth without any visible effects, microscopic black holes at the LHC refer to particles produced in the collisions of pairs of protons, each of which has an energy comparable to that of a mosquito in flight and astronomic black holes are much heavier than those that could be produced at the LHC. Also, the creation of strangelets and vacuum bubbles is dismissed as purely hypothetical at this point and speculation about the creation of magnetic monopoles indicates that such monopoles would be too heavy to be produced at the LHC.
link
 

pooky

macrumors 6502
Jun 2, 2003
356
1
ha!!! But you mean, would have been earth sized :p since the event horizon of the hole would be approx. 9mm...try finding that in space. Reassuring, isn't it..
Well of course I meant mass when I said size. And you're right, there's a bit of a needle-in-haystack problem. But that's for the physicists to solve, I'm just here to provide the ideas.
 

iBlue

macrumors Core
Mar 17, 2005
19,174
15
London, England
More findings...

High energy collisions reveal a paleoparticle

Physicists working on the LHC results have announced their first discovery: a hideous particle from the prehistory of the Universe

The news is historic, or rather "prehistoric" to be more precise! It has taken two physicists studying the collisions at 7 TeV in the centre of mass on 30 March only two days to make an astonishing discovery. From their precise analysis of four events, Alain Grand and Ricarda Owen have found evidence of a new, massive neutral particle thought to have existed in the very early Universe. "It's awful", explains Alain Grand, still shocked by the discovery. "It left horrible tracks inside the detector that made the physicists on duty at the time feel quite sick". No wonder. The particle consists of two strange quarks and one top quark but no beauty or charm quark. The physicists have nicknamed it the "neutrinosaurus" because of its repulsive appearance and prehistoric origins.

Hints of the new particle had already been glimpsed in two events at Fermilab but the statistics were too low to be published. The four events observed at the LHC generated an exponential increase (22=4) in the statistics, allowing the physicists to announce the discovery unequivocally.

The discovery of the particle, which had hitherto been postulated only by an impassioned physicist doing a bit of theory in his spare time, has the potential to turn current theory on its head and to send the entire theory community back to the drawing board. "One important consequence is that all the particles we know today must have had a prehistoric twin", says Ricarda Owen. There will have been a protonosaurus ancestor for the proton (not to be confused with the many-protoned brontosaurus), the electron will have descended from the electronosaurus, and so on. It remains to be seen whether these paleoparticles had antimatter doubles, such as antineutrinosauruses and other antiparticulosauruses. "That's what we're going to be concentrating our efforts on finding now", says Alain Grand. "If they existed, we expect them tobe the exact opposite of the paleoparticles we've found so far, in other words extremely elegant". Whatever happens, the discovery has opened up paleoparticle physics as a unique and exciting new field of research!
 

AdamA9

macrumors 65816
Feb 2, 2010
1,209
336
...and yet we're all still here and not at the center of a black hole. Great job maintaining your grip on reality, science!
We're a while away yet from getting this thing up to speed. Just you wait :rolleyes: LOL
 

RawBert

macrumors 68000
Jan 19, 2010
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62
North Hollywood, CA