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What Are Must-Sees For Open Day At the LHC?
ribasushi writes "The last open day at the Large Hadron Collider is one week away. While I have a solid chance to go, I am dumbstruck by the insane amount of things to see during the 10 hours of the event. Since I do not know all that much about physics, I am turning to the knowledgeable crowd here at Slashdot — what do you think are the most awesome 5 must-see things on the agenda next Sunday?"
xkcd
You have *got* to see the flux capacitors! I realize that you're a bit new to physics, but please press hard to see the flux capacitors. Your guide may laugh uneasily - just keep pressing and don't take "No" for an answer. You won't be sorry.
Make sure you know where to get one in case of an emergency.
3.243F6A8885A308D313
Please, don't move carts with odd-looking crystals in teleporting devices.
Nah, black holes suck!
-Lasse
The LHC is just a tourist trap. It's like Times Square. You go thinking it's gonna be all fun, then you realize it's just a bunch of bright colors and earth eating black holes, and there's nothing to do there but shop for overpriced bosons you could've picked up for half price at a more nondescript collider.
The laws of probability forbid it!
You are right that five physicists who actually know enough about the subject would be an awesome find. But since the poster is asking for guidance on what to see I suspect what would be even more awesome for them is a technically very able physicist who can translate their knowledge into plain english. If there is one thing that would spread the influence of science more than today, it is that rare ability to make it understandable to the general populace.
Asking is no substitute for experimentation.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Since I work here.... I might give a few clues:
:-)
- before you do anything, check the Microcosm museum in the reception building. This one will explain a lot what's happening.
- this one is a must: be sure to make a trip to either the ATLAS or CMS cavern (those are the two bigger detectors attached to the LHC)
- the ATLAS control room
- the LHC control room
- the computing centre in the IT building
- and if you have time, stop by for a tea in building 40
Well, OK. I can claim to be one... But I will out of own for the Open Day... unfortunately.
The thing is that at CERN almost everyone is clueful but about "one thing" mostly. It is hard to find someone who has the "large picture"... The ones who do are generally people who have not been working on the LHC for the past 15 years but those who have been working on it since 2-3 years and before that was working at Fermilab or somewhere else like that. Then they can tell you what's new or revolutionary and put things in better perspective.
Honestly, it looks like the OpenDay will be a mad house. We are expecting at least 40,000 people. The queues are going to be awfully long! I feel like we should have a couple more of these OpenDays to accommodate this huge interest but hey, I am not in the management!! I am just a post-doc!
That said, I have given lots of tours at CERN already. I have taken at least 400 people underground just this past year. (Only 12 people are allowed to go at a time with one guide... ) I think the well-known things like ATLAS and CMS will be completely and utterly packed. So I would like to point out a rare gem... It's the LHC-b cavern where you can actually see the insides of the experiment which installed before LHC-b was installed and is now decommissioned and sitting nearby. The problem with ATLAS and CMS is that they are "done" -- meaning, the experiments are assembled wholly and therefore, it is hard to see it's guts. But you can see the guts of this decommissioned detector, which is kind of neat. I work for ATLAS and I love ATLAS to pieces but I think to try to see it on Open Day, one would need to be at CERN and queueing at 8am... or earlier.
If you have never seen a tape reader with robots running around before, the tour to the Computing Center is really cool -- but then again, since there will be no radiation there, you can visit that even after the 1st of May. (1st of May is the date set by the LHC management board to be the last day of public tours to the LHC and experiments. The rest of CERN will still be "visitable" after that.)
If you can not see ATLAS or CMS on the OpenDay or cant be here on the OpenDay but want to see them, there is a cheat... Most of everyone's requests goes through CERN Visitors Service. And they have a pool of guides but the experiments also have a pool of guides. The visitors service is no longer offering tours as they are completely booked until the 1st of May with their guides. But the experiments might still allow for visitors. The way to increase your chances of getting a private tour to one of the experiments is as follows: Find 11 other people who are interested in seeing the experiment with you and then e-mail the ATLAS or CMS secretariat asking for a tour for 12 people on a April xxth at xx:xx. Then they will forward this request to their pool of guides and someone (like me) might actually give you a tour. We like 12 people tours as this is the maximum we can take down and it is a much better "waste" of our time if the tour group is at maximum number... The e-mails for the secretariats are as follows: atlas.secretariat@cern.ch and cms.secretariat@cern.ch
Good luck!
I am a theoretical physicist and 1) is entirely correct while 2 is misleading at least.
First what is a black hole? Let's say we mean the event horizon. That does not reflect light at all. However, the gravitational field surrounding the BH will of course deflect light the same way the gravitational field around a massive star for example would. Therefore the OP was entirely correct, we can only see the effect of the gravitational field but not light emanating from the BH itself. (At least for astronomical BHs that are very massive and have correspondingly low Hawking temperature). Even taking Hawking temperature into account a BH never reflects light, it has a temperature and gives off perfect black body radiation (in the semi-classical approximation which is the only thing we really know about). That is the black hole information paradox, the outgoing radiation seems to have no information about the ingoing one.
A super-massive blackhole in empty space would be one of the darkest objects you could think of (arbitrarily cold, negative specific heat, yadda yadda). Put some infalling matter around it and you get very bright and energetic processes so BHs can power very bright objects in their vincinity. Put some galaxies and stars behind it and it can lense the light coming from these, put some stars in front it and it can deflect a small amount of light so strongly that it comes straight back at you. That is really due to the space time structure induced by its mass, you don't need a BH for either of these effects. Furthermore you wouldn't say a lense is very bright would you? Nor that it reflects light.