El Reg's LHC visit - Deleted Scenes The Large Hadron Collider - the gigantic underground double-barrelled particle cannon assembled by top boffins deep beneath the Franco-Swiss border - is to start up again "around the 20th" of this month. Not only is the LHC tremendously cool (quite literally) in its own right, it's also the focus of a global hypercomputing grid …
Top stuff, although more pictures and more of the 'unique and fascinating facts' would have been welcome.
It does strike me that, following the previous failure, the whole world knows that the LHC is now gearing up again, but the idea of 'half-power, then see what happens' is rather different to 'it's ready to go' - I can't help thinking they should have publicised this to avoid looking stoopid if it fails again due to an unchecked dead component.
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I'm one of the very lucky people to have worked on this project. I spent something like the last five years making regular visits to the ATLAS experiment installing equipment. I also spent many years before that building delicate detector components working in a clean room.
I have seen ATLAS grow slowly from a pretty much empty cavern to the fully filled massive wall of technology it is now. It's a shame you guys missed out on seeing it, it's a mind blowing sight. It's bigger and more complicated than you can ever imagine. And it just one part of the LHC.
I have even had a chance to walk 300 meters along the LHC tunnel, amazing to consider I covered no distance of the 27 kilometre length. Damn that thing is so big!
Yep, I have my eyeball scanned in, I always find it fun staring into the sensor awaiting for the Thank You message and finally the doors open to let me in.
Yeah, it's up there with the moon landings with regard to the size and complexity of the experiment.
What a privilege it has been for me to have spent so much time and effort and hard work on something as big as this.
What can I say, let's switch that thing on in November...
GO LHC, GO!
"Thought they were colliding at more like twice light speed (from our reference frame of course)"
Err, no. Two objects heading towards each other at the speed of light are still approaching at the speed of light relative to each other. You're kind of missing the whole idea of relativity...
I think you've rather missed the whole point of relativity - the common sense notion of what "relative speed" means cannot be expressed from a third frame of reference. The only meaningful relatlve speed of those two colliding particles is from their own frames of reference.
You can calculate the relative speeds from outside their frames of reference, but you have to use the appropriate relativistic formula. In a very real sense, the relative speed of two objects from a third frame of reference is pretty well a meaningless concept. At normal, everyday speeds in our human world, the difference doesn't matter. Common sense enhanced with a bit of Newtonian mechanics does fine. However, that intuitive sense lets us down completely when understanding relativity.
"doing this experiment is more complicated than sending a man to the moon, and it is not us who says this but those who did send men to the moon."
I've lost count of the number of things about which I've heard that claimed. I think the first time I heard that one it referred to Concorde. Indeed if every instance of this story is to be believed getting a man on the moon is pretty easy.
However in this instance I'm not convinced. In designing and building the LHC they could rely on massive computing power. In getting a man on the moon* they had only rudimnetary computing power and some pencils and paper.
* If they didn't just fake it - happy now conspiracy theorists?
"there are FEWER atoms inside the tubes than there are in outer space"
Fewer is grammatically correct, of course, but it's no big deal that there are fewer atoms inside the LHC than in outer space. I strongly suspect that there are fewer atoms in the Solar System than there are in outer space. Surely it's the density of atoms inside the LHC that is lower than in outer space? That is the LHC houses a harder vacuum than outer space.
My coat's the one with the slide rule in the pocket...
Spotted a few comments about that windows XP screen and though I'd comment. I work for ATLAS.
CERN runs a mixed bag of OSes, XP is used for admin staff, meeting rooms (powerpoint lock-in), public PCs, running software for kit bought from outside (eg. some security stuff, some monitoring stuff) that only has XP software, and for generally being handy if you need a windows PC.
Mac Books are everywhere, I'd say about 40% of physicists use them. About 30% of laptops run windows (various flavours) and about 30% run linux (all flavours under then sun - choice of geek). Pretty much all our desktop PCs have Windows Vista Basic stickers but actually run scientific linux.
Deep underground, in the control rooms and on the grid, the OS that runs the show is scientific linux. It's a home brew based on red hat enterprise linux with a bucket load of custom software.
I know a lot of el reg readers like to see plots of computer usage, check out what the LCG (LHC Computing Grid) is doing:
http://gridview.cern.ch/GRIDVIEW/job_index.php
Have a click around, this is what can be done with "cloud computing" and red hat
"I am sure the meant "less atoms per unit of volume", not as an absolute number..."
The correct form would stil be "fewer atoms per unit of volume" as atoms are, in principle, countable.
It is, of course, an oddity in English that we have the comparative adjectives "fewer" and "less" for discrete and non-discrete quantities, whilst the opposite adjective is "more" in both cases. It is also worth noting that "less" is commonly used for some countable items, such as "less than four weeks", although perhaps those are justified by the actual underlying quality (time in this case) being effectively continuous in nature.
Beer alert ... don't drink the water.
I never got a response to the question of what do they do to all the damaged particles. Trillions of shock treated particles dumped twice a day next to one of the largest fresh water sources in Europe. The stuff in the tube still numbers enough to be part of the water content of every person on earth within the first days of running. Statistically speaking of course.
Does the nation with the greatest number of accelerators have fertility problems. Perhaps long ago someone said we should not paint ships with anti foul because it would poison the oceans. My guess is that they were called an idiot. Back then there was one dead sea and now there are fifteen of them, some as big as continents.
Yeppers, the guys at CERN use Scientific Linux for the most of the machines. Have a look on the web for it everyone.
Windows is used on machines used for simple non-LHC tasks.
But as zenkaon says it's amazing to note how many people own Apple laptops at CERN, the Physics guys really love them. There has been lots of people there also saying that iMac are becoming popular as desktop machines, can't remember which control room it was but one of them is apparently fitted out with Apples.
Down in the ATLAS pit in one of the side equipment rooms (USA15) there have appeared lots of aluminium iMacs.
I'm not a fanboi, but all those people who keep calling Apple computers "Toys" should be aware of how many people use them at the place that invented the WWW...
One assumes that you are either making a joke, or had imbined rather a lot of intoxicating liquid before you wrote that lot. On just one minor point, it's a bit difficult to imagine a dead sea larger than a continent as they only ones that I know of that are in such a state are inland.
The ATLAS satellite control room (normal one isn't big enough for all of us!) is full of iMacs - but they mostly run scientific linux, only your crippled with one mouse button. I wouldn't recommend scientific linux to most people, it's not so good with a monitor, keyboard and mouse. Much better to use fedora or ubuntu. However, when you get several hundred racks of pizza boxes distributed worldwide....red hat (or derivatives) all the way! No other credible option really.
The reason physics guys love macs is because when you open a terminal you have unix.
Steven Jones wrote:
It is also worth noting that "less" is commonly used for some countable items, such as "less than four weeks", although perhaps those are justified by the actual underlying quality (time in this case) being effectively continuous in nature.
"Less" is the right word in that case because you are measuring a continuous quantity, viz. time. "Fewer" would be correct in a context where the time period referred to was quantized in one-week periods, but you'd probably have to be pretty specific in that case if you wanted to avoid being charged with "failure to pedanticize".¹ "Getting the LHC up and running should take fewer than 1000 one-week time slots."
I drank less than six gallons of beer.
I drank fewer than six one-gallon bottles of beer.
¹ Though given NuLabour's chronic distrust of anything with a whiff of elitism about it (e.g. talent, experience, education, intelligence, smarts, gumption, having the chops, consistency, subtlety, etc), pedantry may be on the list of thought crimes to be outlawed.
Been a part of the extra screensavers in (Open)SuSE for years, so I assume other distros have it too, SuSE was never snappy with adoption.
There's even a nice 3D one which I like. Anyone any idea where I can get this for Ubuntu? And is it part of Mandriva (or is it Mandrake, just pulled in the new DVD over bit torrent)?
(note: it simply means I haven't made up my mind about new distro yet - getting bored with OpenSuSE)..
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