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Thanks for posting this StarkingBarfish, hopefully the sensationalist doomsday crap will finally end. Several of the professors are the university I'm going to are working/ have worked on the LHC, so as a Physics major I'm getting really excited as the test start is drawing closer, even if it's going to take tons more tests and a lot of time processing the data before anything can be really interpreted out of it. One of the professors involved with the LHC send this out in a departmental email for some reason yesterday, figured GBS might find it amusing/ a really overly simplified way to explain the LHC via... RAP: http://www.youtube.com/watch?v=j50ZssEojtM
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# ? Aug 7, 2008 23:45 |
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# ? Mar 28, 2024 22:24 |
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Since people have been working on putting together the LHC since the 80's have they already started designing the next biggest, baddest particle accelerator on Earth or are they waiting to see what the LHC can do before planning LHC2: Electromagnetic Boogaloo?
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# ? Aug 7, 2008 23:46 |
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The Artificial Kid posted:Now I'm not saying the LHC is dangerous. I expect it's safe. But that is a dick argument. Just because nobody will be around to know or sue if it goes wrong, doesn't mean it's an unimportant question. It's like he's being a juvenile solipsist, and taking it upon himself to be that way on behalf of all of us instead of doing his level best to clarify the issue for people who don't have ten years of physics education. You're absolutely right, it would be a dick argument, but he said this after discussing the fact that many, many papers have been published in recent months dismissing the possibility. I agree that it is a very unscientific answer, but many physicists find it hard to respond to these questions because it would be asking a fish if bicycles are an effective form of underwater transport. I guess as scientists we're guilty of not trying harder to educate the public on what is and isn't science, so we tend to come across as condescending when we are dealing with people who have been misled. It is like wondering if someone is trolling or not. As for the Karl Pilkington comment, have you ever seen me and him in the same room? Just sayin', he might have gone ton night school... Fusion- not my area of expertise I'm afraid. I was at a seminar last year that suggested '50 yrs before it reaches commercial reactors' but I suspect more money will be put into it now that oil is truly hosed. Perhaps a speedup is on the cards? Lastly- Well spotted on the LHCb. The reason it is such a different shape is because the particles we are interested in tend to exit from the collision at an angle very close to the direction of the beam. The other experiments are looking around the entire collision point, in a cylinder. We are looking only at stuff spat out in one direction, at a narrow angle. Out 'proton hole' doesn't exist as such, as the collisions actually occur at only one end of our detector. They occur in the center for the other experiments.
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# ? Aug 7, 2008 23:47 |
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one of my favorite daydreams / ponderances is that the Big Bang that created our universe was basically people (scientists) destroying their world with the exact same type of Big Bang-type experiment. I'm not a doomsayer. I just think it's an awesome theory.
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# ? Aug 7, 2008 23:50 |
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ReV VAdAUL posted:Thanks for posting this, I have a semi-serious question, are there any likely everyday applications the results from these experiments will have? I imagine that if so its only very indirectly but I love the idea of something along the lines of "our washing machines are now 30% more effective thanks to LHC research!" Another commonly asked one- There are almost no direct every day applications from the work we do. In your home right now, there are at least 3 pieces of particle physics you use frequently, the smoke detector, the microwave, and the Cathode Ray Tube TV. Those are all old inventions though. The problem is the energies we deal with are just not possible to make on a tabletop yet, and even if you could, you'd not be able to do much practical with them. The cool part however, is that there are many indirect applications. The superconducting cables we use in our magnets save insane amounts of electricity. They're being tested in the US at the moment as underground cable for long-distance transmission of HV. The web is ours as well, invented at CERN by Tim Berners-Lee as a tool to help us shuffle data around universities.
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# ? Aug 7, 2008 23:53 |
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lapse posted:I imagine that the entire machine has to be almost exactly perfectly round for the beam to not smash into the outer wall of the solenoid thingy. (maybe that's wrong?) How do injection points and collision points work so that the beam can be shifted without smashing into the wall of the machine? You're right, in that the beam smashing into the outer wall would not be a good thing. However, the dipoles you see are actually straight instead of being curved. The magnets are tuned at different field strengths and varied extremely precisely to contain the beam. This is all automated and a string of sensors around the beampipe monitor and make adjustments in nanoseconds.
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# ? Aug 7, 2008 23:56 |
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Thankyou, I do like how its uncertain how quickly we'll see practical applications from the experiment itself (if ever) but the system used to gather the data from the experiment has almost imeadiate applications for the internet. StarkingBarfish posted:Another commonly asked one- There are almost no direct every day applications from the work we do. In your home right now, there are at least 3 pieces of particle physics you use frequently, the smoke detector, the microwave, and the Cathode Ray Tube TV. Those are all old inventions though. The problem is the energies we deal with are just not possible to make on a tabletop yet, and even if you could, you'd not be able to do much practical with them. Ah right so its like NASA, I don't drive to work in a moonbuggy but I do use velcro. Well that is cool then, thanks for your response.
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# ? Aug 7, 2008 23:59 |
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Fantastic thread, very well written, lots of awesome information to read, thanks a lot for this ! Question: Where does the name come from ? Is Hadron the name of a scientist somewhere ? Edit: Is it related to this ? So why is it called Hadron collider if it doesn't collide Hadrons, but only protons and lead ions ? Alex007 fucked around with this message at 00:08 on Aug 8, 2008 |
# ? Aug 8, 2008 00:05 |
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Bonk posted:A few for you: It is a combination of the two- We're deadly serious when it comes to our work, for obvious reasons, but we also see the funny side. I guess it is the same as in any job, but there is quite a bit more geek humor. The general attitude I think is along the lines of 'we are doing this because we love it, seeing as there sure as poo poo isn't much money in it.' and as a result people are generally happy in their work. Bonk posted:Assuming you understand the results of this thing, what do you use it for after that? Does it have any theoretical applications or is it strictly to observe the matter's behavior? There are a number of possible outcomes from this experiment, I'll list them in order of shittyness: - We see the higgs boson, and Nothing else. This would really suck balls, as it pretty much ties up the standard model, and says 'that's all folks'. It puts us experimentalists out of the job, and leaves theorists without much to do either. - We see Noting at all. This isn't as bad as it sounds. It means the theorists are left with a lot of explaining to do, and it means the experimentalists can say 'The theorists hosed up, we need a more powerful machine to find their improved theory' - We see the Higgs, but not quite where we expected it. This is a good sign of 'New Physics' which we capitalise and call NP in our presentations. It is a way of saying 'gently caress yeah, something is going on and we don't understand it yet. There's gold in them hills, lets get digging'. - We see something completely unexpected. See the previous point, but with the added headscratcher that higgs isn't in there. The LHCb is doing exactly what you suggest, in that it probes and constrains the possible theories that exist right now for CP violation, the theory behind why we think the universe is mostly matter.
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# ? Aug 8, 2008 00:06 |
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As a Physics major, I'm waiting anxiously for the flipping of the massive "On" switch on this thing. A few of my professors work/have worked on this thing and ditch out on class every once in a while to head over to CERN.
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# ? Aug 8, 2008 00:08 |
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How many buttons are there to turn it on? Who gets to press them?
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# ? Aug 8, 2008 00:08 |
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What I'm wondering, Starking, is how much (if any) kinetic energy these beams might have. At those speeds, I imagine that even subatomic particles would be pack a bit of a punch.
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# ? Aug 8, 2008 00:09 |
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What's to stop the two colliding beams damaging the equipment that's supposed to detect the results? If you use giant carbon blocks to stop a single beam, what prevents all that energy doing damage? P.S. You kids get off ma fuckin lawn and don't look at me when I'mtalkingtoyou
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# ? Aug 8, 2008 00:11 |
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This is all very "We're waiting for you in the test chamber, Gordon."quote:We can measure how much antimatter exists now, and it is several billion times less than the amount of matter in the universe. The thing is, this shouldn't make sense- if the same amounts of matter and antimatter were made, and they mixed with each other, they'd annihilate again leaving nothing behind. The fact that there was less antimatter than matter is the reason we exist today, but we don't know why. The LHCb will give us a deeper insight into this. Now I have only the vaguest concept of physics, so forgive my naivety, but as far as I was taught the "Law of Conservation of Matter and Energy" says that matter cannot be created nor destroyed, correct? Ergo, wouldn't this test pretty much undermine that founding law if you were able to, say, decipher where - or how - those masses of matter/antimatter came into being? Simple philosophy dictates that something cannot come from nothing, no? ... ... You know, this is why I stuck with genetics...
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# ? Aug 8, 2008 00:13 |
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Phy posted:This is why one pays ten bucks to post on an internet forum. The difference between a PPE and a PPT (particle physics Experimentalist/Theorist) is that PPE's work for a living Actually, the PPE's tend to be jack-of-all-trades, masters of none. To do my job I need a good knowledge of electronics, statistics, power engineering, programming, design, theoretical physics, applied physics, chemistry, engineering... The list goes on. We have to design and build these experiments, as well as running them, and deciphering the physics from the results. The theorists are in general far more specialised, and tend to work in an office stacked with papers to read, their tools a pen and paper, or chalkboard or computer. The PPE has a much more diverse career ahead of himself, but tends to be pretty thin on the ground. As for the higgs mass question, LEP set the lower limit, and the mass of the top quark constrains the upper limit, if I recall. If it is above the proposed upper limit, it'd be difficult for the higgs to couple to anything in the standard model. There are a number of theories though, depending on the type of Higgs (there's more than one). To go any further is beyond my knowledge though and you'd need a theorist.
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# ? Aug 8, 2008 00:14 |
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Novian Trek posted:This is all very "We're waiting for you in the test chamber, Gordon." From what I understand matter can become energy in different forms. You can't destroy matter but it can turn into heat or light for example.
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# ? Aug 8, 2008 00:14 |
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What language is widely spoken over there? English?
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# ? Aug 8, 2008 00:16 |
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Do you know the girl who made the CERN rap? Because that poo poo is dope as gently caress. I'm listening to it right now and I might or might not know all the words to it. StarkingBarfish posted:As for resonance cascades- someone put up a big red 'black hole abort' button in the CMS cavern.... Also a picture of this would be awesome. Any photos of the behind-the-scenes rooms and stuff would be pretty neat, or is that not allowed? Do you have your own little office or something?
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# ? Aug 8, 2008 00:16 |
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BklynBruzer posted:What I'm wondering, Starking, is how much (if any) kinetic energy these beams might have. At those speeds, I imagine that even subatomic particles would be pack a bit of a punch. Yes, that's quite an understatement. As for the KE, relativistic KE is given by KE = mc^2 - (restmass)c^2. I'm not exactly sure what that ends up being, but it's definately going to be a crap load of energy. As previously mentioned, it heats up large blocks of carbon by several hundred degrees in a matter of seconds.
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# ? Aug 8, 2008 00:16 |
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If all the matter in the universe was in such a tiny space at the beginning why wasn't it a black hole? Because space hadn't yet expanded? Or maybe it still is a black hole? But then compression of the matter wouldn't mean the same thing.
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# ? Aug 8, 2008 00:18 |
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Novian Trek posted:This is all very "We're waiting for you in the test chamber, Gordon." Really, the law is more that energy is not created or destroyed. When a particle and an antiparticle come together and annihilate, energy is given off in the form of photons, thus preserving energy.
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# ? Aug 8, 2008 00:18 |
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Kaiho posted:Excellent, well-written and thoughtful thread. Thanks for starting it. I'm glad you write with a clarity of expression suitable for us not versed in physics, and am equally glad you told the neckbearding theoretical physicists to stay the gently caress away. Sure thing- http://arxiv.org/abs/0807.1938 The arxiv hep-ph preprints are an awesome place, often they are far too theoretical for me, but there are often a few gems in there. For a more friendly and often entertaining look at what we do one of the better reads is cosmic variance.
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# ? Aug 8, 2008 00:19 |
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GoatSeeGuy posted:Since people have been working on putting together the LHC since the 80's have they already started designing the next biggest, baddest particle accelerator on Earth or are they waiting to see what the LHC can do before planning LHC2: Electromagnetic Boogaloo? First off, "LHC2: Electromagnetic Boogaloo?" is easily the best name for the upgrade I've ever heard. I am putting that up for nomination. The LHC2 is called the 'Super LHC' at the moment, and is planned to come into effect in 5-10 years assuming we have the cash. It isn't a complete rebuild, but it'll be a lot more powerful than it is right now. The detectors will be beefed up too. The idea is that the longer you run an experiment for, the less improvement you get. Eg: running for one year nets you a result, running for two nets you a really accurate result. Running for 4 doesn't get you much more than you got running for 2. By beefing it up and doubling the rate, you keep on top of the particle physics equivalent of Moore's law. The SLHC is well into the planning stage, and my experiment is already looking into new designs and components before it has even started. In addition, the ILC was planned to take up the gauntlet, but because the US and UK pretty much dropped it, us PPE guys are scratching our nuts as soon as the LHC ceases to be useful. We need to find something juicy to keep ourselves in business.
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# ? Aug 8, 2008 00:26 |
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Just how many PhDs do you think will be earned from all this?
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# ? Aug 8, 2008 00:27 |
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Alex007 posted:Fantastic thread, very well written, lots of awesome information to read, thanks a lot for this ! Protons are in fact Hadrons. The wikipedia article is pretty badly written, so here is a better idea of it. Hadrons are made up of quarks. That is pretty much the definition. The thing is that there are two types of Hadrons: Mesons and Baryons. The proton is a Baryon, so it goes: proton = a baryon = a hadron.
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# ? Aug 8, 2008 00:31 |
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err posted:How many buttons are there to turn it on? Who gets to press them? This is the 'button' http://www.youtube.com/watch?v=Jy2179DcNT8&feature=related The CCC or Cern Control Center. each of the 4 'islands' deals with a different stage of the LHC. The injectors, the initial accelerator called the SPS, the LHC cooling system, and the LHC itself. It requires on average about 40 staff to monitor, control and diagnose just the beam. The detectors will have a similar number of staff themselves in each of their own control rooms monitoring their experiments, and all are interconnected so that if a detector sees a problem with the beam, so does the CCC. To actually inject the beam, accelerate and collide will be pretty much automated as the timing is much too fast for human error, so it will probably be achieved with a couple of mouse-clicks.
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# ? Aug 8, 2008 00:36 |
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Hey StarkingBarfish, a few questions if you don't mind. 1. What is with the multiple proton tubes in the LHC? Is this so you can fire in succession several proton collisions without many delays? I always figured the LHC to be just 1 tube. 2. How do you ensure containment? I know that even with decades of work into the tokamak they still have issues with energetic particles escaping confinement, so much that they are working on using liquid Lithium walls with a kind of filter to pass the fuel back in. Even then, tokamaks usually operate in the 100 keV range, and you have to be at least in the 10's of MeVs, right? Especially since your beam is self-repelling, or at least I'd imagine it to be, confinement must have been an issue in the design. 3. Along that line, how are you generating such an energetic beam of pure protons? I'd imagine taking some hydrogen gas, ionize it, and have some anode or something collect all the electrons. However, I'm not sure how you guys come up with a means to generate those kinds of temperatures. Is it electrostatic, electromagnetic, wave based? I guess with a low quantity of protons you can just try to use a massive voltage drop with a power supply, but that seems difficult to make it work. 4. The last one is more of a theory question, so I apologize in advance, but even if they find the Higg's boson, how will that explain how gravity works? I once read that in general, each force has a "working" particle so to speak. For electromagnetics, its the photon, for gravity it is supposed to be the Higg's boson, and for the weak and strong forces I can't remember. Then these "working" particles cycle between the two bodies interacting, or something like that. Either I was misunderstanding or that just came off as a giant hand waving argument. Does anyone actually have an idea why a force derived from a field is obtained by particles? A bit wordy, but these were some of the things that I find curious about the LHC. Thanks for filling us in with the behind the scenes scoop, I wish the US would get off its rear end and get back into high science.
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# ? Aug 8, 2008 00:37 |
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So what will you be doing as this is ran? Will you just sit in an office above ground watching your computer fill up with data or will you actually be underground doing something, and if so what?
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# ? Aug 8, 2008 00:38 |
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StarkingBarfish posted:so it will probably be achieved with a couple of mouse-clicks. They should run a lottery for every country involved in funding/contributing scientists/money, and find the lucky person to turn it on. Sell tickets at $1, then use the profit to fund a bigger and better machine.
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# ? Aug 8, 2008 00:38 |
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Excellent thread, thanks for the time and effort you've put into it. You have a great way of explaining this stuff so that even a non-scientific dude like myself can grasp it. You touched on the Higgs boson, and I've seen it mentioned in other LHC threads. Any chance you could give an explanation of what it is, and why we want/need to find it. I've looked in Wiki and a few other places, but none of them are as accessible as your posts.
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# ? Aug 8, 2008 00:39 |
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BklynBruzer posted:What I'm wondering, Starking, is how much (if any) kinetic energy these beams might have. At those speeds, I imagine that even subatomic particles would be pack a bit of a punch. Another good one- the 'energy' of the LHC beams is measured in TeV, or Tera electron Volts This is the kinetic energy of a proton in the beam. If you type into google "14TeV in joules" their calculator will do the conversion for you. It is a very small number, but then you must also consider that the proton is extremely small. It is roughly equivalent to the energy of a mosquito in flight if my memory serves me, but compressed into a space 10^26 smaller than the mosquito. It is enough energy to heat up a few tonnes of carbon beam dump to a couple of hundred degrees, so I'd say a punch is an underestimate!
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# ? Aug 8, 2008 00:41 |
Will there be a lever that a researcher can pull when they find the Higgs Boson that unleashes a crapload of confetti and balloons?
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# ? Aug 8, 2008 00:41 |
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quote:So what will you be doing as this is ran? Will you just sit in an office above ground watching your computer fill up with data or will you actually be underground doing something, and if so what? If its anything like what I do or what most other labs are, I'd guess he has his work station (maybe not even in his office but in some control room/station) watching a particular diagnostic and crossing his fingers that nothing breaks. Despite how cool this stuff is, a lot of it is digging through the collected data for days afterward to find what you are looking for.
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# ? Aug 8, 2008 00:42 |
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I heard that CERN asked the band Spiritualized to play at the opening/start-up ceremony but were unable to do so, is another band going to be playing instead? This is important.
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# ? Aug 8, 2008 00:46 |
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Are there any tours available of the place? Open days etc? It would be fascinating to see the thing up close
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# ? Aug 8, 2008 00:54 |
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my2k posted:Do you know the girl who made the CERN rap? Because that poo poo is dope as gently caress. I'm listening to it right now and I might or might not know all the words to it. The behind the scenes photos are best found by googling, to be honest. The nice thing about CERN is that it is an international, publicly funded organisation. The work we do is in essence free for the good of humanity. There are copyrights, but the information itself is available to all. If you check out CERN's document server, CDS, it has all the photos ever taken at CERN.
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# ? Aug 8, 2008 00:55 |
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Happy-Fun-Ball posted:If all the matter in the universe was in such a tiny space at the beginning why wasn't it a black hole? The density was enormous, but so was the energy. Essentially it would be like the first few nanoseconds of a nuclear explosion. Vast amounts of matter/energy confined in a minute space, but itching to release itself into the infinite void of its surroundings.
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# ? Aug 8, 2008 00:57 |
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narby posted:What's to stop the two colliding beams damaging the equipment that's supposed to detect the results? If you use giant carbon blocks to stop a single beam, what prevents all that energy doing damage? The beam is only doing damage as long as it is hitting something. The rest of the time it is contained in vacuum, guided by strong magnetic fields that keep it off the walls. The detectors don't go near the beam, they detect the things thrown off at the interaction point. The closest thing to the beam in the entire LHC is part of my experiment, called the VELO, short for VErtex LOcator. It sits 8mm away from the beam, and we are worried it can be damaged, so we have it sitting on a retractable shelf that slides out until the beam is stable.
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# ? Aug 8, 2008 01:01 |
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narby posted:Are there any tours available of the place? Open days etc? It would be fascinating to see the thing up close I went on a tour (several days' worth of tours actually) round CERN in June 2007 (it was a school physics trip), but I don't know whether they are still doing them as it's getting closer to starting up. Either way, you'd have to be part of a group... I guess they have more info on the CERN website. Anyways on my tour I got to see a whole load of awsome stuff, the most memorable to me being the Atlas detector (being put together), basically because it was so goddamn massive. Truly jaw-dropping stuff. I didn't get to see inside the tunnel as they were still working on it at the time I guess, and it's not very interesting anyway, as the OP says, compared to stuff like Atlas. I also got to meet (I think, my memory's pretty poor) the guy who was in the office next to Tim Berners-lee as he was creating the Web, plus a ton of smaller particle accelerators, and other physics-y stuff. It was a pretty cool week.
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# ? Aug 8, 2008 01:05 |
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# ? Mar 28, 2024 22:24 |
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Gordon_The_Fish posted:Just how many PhDs do you think will be earned from all this? Very many indeed. There are some 7000 researchers involved, a good chunk at the postgrad level. In Edinburgh our group is pretty small, but already at least 6 students have gotten PhDs from it, and another 3 are due to submit this year. I'd say by the time it is done and dusted, there'll be a thousand or so PhDs from it. That excludes the upgrades.
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# ? Aug 8, 2008 01:06 |