Yesterday a new web-site was launched by the DOE and NSF, called US/LHC, which will be devoted to the role of the US in the LHC project. Besides news and descriptions of the science and the experiments, it will also include blogs by several physicists involved in experiments at the LHC. This new web-site joins several other similar ones, most notably one devoted to the ILC, and an umbrella one for US particle physics called Interactions.

I’ve sometimes wondered whether this huge publicity onslaught for the LHC is a good idea. Just as this new web-site is coming on-line, I’m starting to hear unconfirmed reports of possible very serious delays in the LHC startup, ones which may push back the beginning of experiments by a year or more. The current schedule includes no extra time for cooling down sectors of the machine which have to be warmed up to deal with one problem or another, and this cooling is a tricky months-long process. If these rumors turn out to be true, this will be good news for the Tevatron, which will have the energy frontier to itself for longer than expected. But it will definitely be very bad news for CERN and for particle physics in general, both of which have just about all of their eggs in this heavily publicized basket.

Update: From the comments here and e-mail I’m getting, it appears that others are hearing these same rumors: the first physics runs are likely to be in 2009, not 2008, due to problems that have shown up as they have started cooling down some sectors of the machine.

Update: Peter Steinberg at the US/LHC site blogs about the conundrum of whether he should be dealing with “gossip from unverified or anonymous sources”, and decides he’d better not. I suspect one consideration is that his blogging role puts him in a sort of unofficial spokesman capacity, which is rather incompatible with rumor-mongering. On the other hand, I don’t have this problem…

An informed commenter reports in the comment section about details of some of the problems that have cropped up in the last month, and that the “best guess” for the delay that these will cause is about two months. This would move the start of a physics run from next July to next September.

Update: Via the Resonaances blog, here’s the video of a September 13 colloquium talk by Lyn Evans about the LHC commissioning. Evans describes in detail two of the problems that have shown up that motivated some of the rumors: leaks that have appeared during the first cool-down of certain sectors of the machine, and problems with some of the plug-in modules that interconnect the magnets. It remains unclear if these problems will cause slippage in the schedule, and if so, how much. News about what is going on with these problems is posted here.

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26 Responses to US/LHC

  1. My story in this month’s Physics Today magazine Multiple problems push LHC start to next spring might answer some of your questions.

  2. Peter Woit says:

    Thanks Paul,

    I did see your article, and what I’ve been hearing recently involves some of the same problems you describe there. But what I’ve heard is that the problems are more serious than originally thought, and that the startup date of next July will have to be pushed back. Maybe this is wrong, so I’d be curious to know if your sources for that article are still saying that things are on track for next July.

  3. Hi Peter,

    I also am hearing of about one year of delay of startup (pilot run end 2008, first data end 2009), due to some structures that may have broken during cooldown and need replacement. Yours is the fourth source of more or less the same information, so I would say it may well be not confirmed, but it is a pretty solid piece of bad news.


  4. Thomas Larsson says:

    This is sad news. However, Tevatron II also had a lot of initial problems, not to mention the SSC debacle. The CERN people have spoiled us with a track record of completing their projects on budget and ahead of time.

  5. Coin says:

    So these USLHC blogs. Should we expect them to be more or less independent? Or will the DOE or somebody be looking over their shoulders every moment monitoring the content?

    I really like this idea of scientists on big projects like this blogging, because it seems like potentially a great way for the public (i.e. me) to get interesting and unusual information about the experiment as it progresses. Unfortunately, this potential seems to be in direct conflict with the NSF/DOE’s likely goal in setting up this web page in the first place– that is, as a vehicle for generating publicity for the experiment, probably positive publicity.

    Let’s say the most pessimistic comments on this page turn out to be right, and the LHC has some delays coming. Will we see candid posts from the USLHC scientists about the delays and what they mean as they happen? Or will these blogs be only for reporting good news?

  6. Coin,

    I can’t answer your question, but what I can say is that I am blogging, I work in CDF and CMS, and I am rather erring on the side of dispersing more news than I should, according to many of my colleagues. That is because I believe outreach is more important than obsessing about what the funding agent could read in distorted press reports.

    So the bottomline is, read it in my blog!


  7. Peter Woit says:


    An interesting question. If these reports turn out to be accurate and serious delays are ahead, it will be interesting to see how the bloggers and the website handle it. It looks like the website itself will be maintained by people hired specifically to do outreach for the project, and their job depends on putting out whatever those responsible for running the project want to be made public. On the other hand, the bloggers are scientists. I doubt they are being paid much if anything to do this, so they have freedom to write about what they want to, although also presumably will feel some obligation not to embarrass the sponsors of the web-site.

    In any case, it you want relentlessly upbeat blogging about how wonderful everything is in this area of science, there are some very prominent blogs you can go to for this, and they aren’t even sponsored by the DOE or NSF.

  8. anonymous says:

    I don’t know of any rumours about a delay in starting LHC. What I do know is that CERN is presently in the process of choosing a new director general who will take over in Jan 2009.

  9. peter says:

    we’ve known for a long time now that the LHC will come on line on April 21,

    Day One: Tuesday, April 21, 2009

    A slice through spacetime . . .

    The control building for CERN’s Large Hadron Collider was new: it had been authorized in A.D. 2004 and completed in 2006. The building enclosed a central courtyard, inevitably named “the nucleus.” Every office had a window either facing in toward the nucleus or out toward the rest of CERN’s sprawling campus. The quadrangle surrounding the nucleus was two stories tall, but the main elevators had four stops: the two above-ground levels; the basement, which housed boiler rooms and storage; and the minus-one-hundred-meter level, which exited onto a staging area for the monorail used to travel along the twenty-seven-kilometer circumference of the collider tunnel. The tunnel itself ran under farmers’ fields, the outskirts of the Geneva airport, and the foothills of the Jura mountains. …

  10. Yatima says:

    > choosing a new director general

    But that is not correlated with the rumors about delay, right? Delay may be a good thing. Hearing about the compressed schedule to go live next year with no preliminary testing made me cringe. These tricks never work out, except – maybe maybe – if you know exactly what you are doing (i.e. you are doing it for the fifth time or so).

    Now… will politicians head for the door upon hearing this or is LHC funding still assured? On the other hand, I probably don’t understand the funding thing. Paul writes: “Construction of a new $150 million injector will start in 2012 when CERN finishes paying off the loans it took out to build the LHC”.

    They took out loans? With what collateral?

  11. Coin says:

    Dorigo, I do read your blog and it’s a great example of what I would say we can hope for from blogging experimentalists, off the top of my head it would be that or the kind of thing that John Conway (but not that John Conway, apparently?) occasionally posts at Cosmic Variance. If the USLHC blogs manage to occasionally give us that level of insight into the project I’ll be ecstatic. Of course, I’m not picky, I guess anything’s better than trying to get one’s science news from the popular press?

    [CERN] took out loans? With what collateral?

    Perhaps if the loans are not paid, the banks will repossess the rights to the Z Boson. I mean consider how many Z Bosons there are in active use, the licensing revenue from those things must be enormous.

  12. JoAnne says:

    By international treaty, CERN recieves a fixed stipend each year from each member country. These stipends form their budget for current operations as well as R&D and construction of future facilities. In order to build the LHC in a timely manner (rather than having the constuction stretched out for more years), CERN took out loans against their future stipends. Each year after the LHC construction is finished, CERN will repay part of the loans with the fraction of these fixed stipends that is not used for current operations. Given the fixed amount of these stipends, it is known (and set by agreement) that the full amount of the loans will be repaid in 2011. Thus in 2012, there will be money available from the fixed stipends for new projects. This is a fantastic and stable funding model. Sure wish we could fund science in the US this way!

    I haven’t heard any rumors about further delays yet, but would not be surprised. In fact, I think we should anticipate a certain amount of small issues to arise as they commence operations. It is much better than they turn on the machine carefully and correctly!

  13. “It is much better than they turn on the machine carefully and correctly!”

    –> I hope the previous commenter does not imply that there are other ways to start running a 14 TeV proton accelerator, whose beams carry the energy of an aircraft.

    Unfortunately, it is not because of care and attention to detail that the thing will probably be delayed. Rather, there are things that need servicing along the tunnel – many of them – and even figuring out where they are isn’t easy! Imagine being in the situation when it does not seem that silly the plan of running tennis balls through the beam pipe to figure out where a few hundred among 4000 pieces blocking the path are, and having to dream of teams of grad students cycling around the tunnel to find out. It’s just that bad.

    No, I would not give the picture those soft rosy tones JoAnne likes to paint. The further delay, if confirmed, is a disaster to a large number of people who were counting on real data first at the end of 2007, then in 2008, then “a little in 2008 – 1 or 10/pb, and then 2-3/fb in 2009 – but we’ll publish W and Z cross sections end 2008!”, and now apparently not more than minimum bias until late 2009. For a theorist and assistant professor, sure, no hurry. But for a grad student who spent the last few years building things in the hope to finish his PhD in glory, it is a hammer blow. And it is not much less so for a fresh post-doc who has been hired to do data analysis and will instead spend three years doing Monte Carlo studies, not publishing anything meaningful.

    Let’s just hope that the rumors coming from CERN have been amplified through the echo of the caverns.

  14. Ellipsis says:

    Here is what I hear (gosh, why is there no better public source for these things than a blog by a mathematical physicist which is supposed to be about the problems with string theory?):

    There are two problems which have cropped up in the past month:

    1) Vacuum leak in arc 8-1

    2) Problems with the “plug-in modules,” which are the interconnects between dipoles. About 1% of them (in sector 7-8) failed and were damaged during the cooldown recently.

    It is not clear how much time fixing these will add to the schedule, although apparently a year would be extremely pessimistic. Unless other problems crop up (not unlikely), the best guess (and it is a guess at this point — that is why you’re not hearing any official statements) for the amount of time this will add to the schedule is approximately 2 months or so. That’s a guess. Apparently the CDF spokespeople have announced they thought the delay would be longer, but remember that CDF is looking for an extension on Tevatron running time (and its spokepeople are not the most knowledgeable about this situation). Relax and wait until the people who know, know better.

    As for the US LHC blogs, personally I certainly wouldn’t worry about any active censorship or anything like that. I might be a little more concerned about them just becoming boring “corpora-blogs” because of their restricted mission and focus. Wait and see.

  15. JoAnne says:

    Dear Less of a dreaming optimist than JoAnne:

    I have been waiting for data at the TeV scale since the summer of 1983. That was my first summer of doing research and was when it was announced that the US was going forward with the SSC. Fast forward, past all the super-collider calculations I did, to the Fall of 1993 when the SSC was cancelled and my paycheck was being paid by an SSC Fellowship.

    You have no idea what it means to wait. I have most likely been waiting longer for data at the TeV scale than you have lived. Believe me, you and your career will survive the waiting. Life (and physics) as we know it will not end.

    Yes, the LHC is already delayed and likely will be delayed more. But, after waiting 25 years, the very large numbers of people that have worked so hard and have waited so long already will find that it is OK to wait another year or so. And yes, the waiting will be because the people in charge of starting operations are careful. They will only test one segment at a time, carefully, so that a catastrophic event does not occur. And a safe startup will happen, precisely because of attention and care to detail.

  16. JoAnne,

    sorry, but I am older than you figured, I have a job, and it does not depend too much on LHC turning on or being canceled. I do, however, feel concerned for the tens, maybe even O(hundred), people that do not have the luxury option of waiting, and have to drop out of the field because they have to go on with their lives rather than living through 10-year PhDs. Seeing physics at the TeV scale is sure nice, but I do not shed a tear if our children will do it rather than us. There are sociological implications that to me are more important.

  17. Ellipsis says:

    I don’t think anything related to these current issues has the remotest chance of turning a 5-year PhD into a 10-year one. Agreed that it is clearly somewhat of a concern when startup has been “a year from today” for a year now, but there haven’t been any true disasters … yet. This is life, and funding agencies, employers, and just about everyone working on the projects have anticipated this level of issues. I think you should save the major complaints for when the beampipe gets a vacuum leak inside the CMS silicon, or when joule heating breaks the rest of the PIMs, or something like that. There are plenty of things that could go majorly wrong, and might — you’re early (if ever). And that will be life too if it happens. How else do you suggest science progress?

  18. Ellipsis says:

    Furthermore, even if a disaster does occur, in that case it is likely that the Tevatron would be kept running until things improve. Most people working on the LHC also work on another project, partly because of the possibility of these kind of issues. It is fundamentally different than the SSC. I think very few will have to leave the field, even if a disaster occurs. Students can be shifted to a different project if necessary. People are more careful this time around.

  19. observer says:


    whining about a (possibly inexistent) one-year delay is ridiculous. Such delays are to be expected, with a certain probability, so anybody working on this should know what their chances are and take appropriate precautions. If someone is betting their phd on a certain date and time for the start of operations, they’re making the wrong bet.

    To extend JoAnne’s description of the consequences of the SSC cancellation, I know many people who went into finance and computing in those days, who didn’t even work in SSC physics. At least one who didn’t even work in particle physics proper, but in astroparticle physics. There was a big crunch in the job market and everybody paid a price.

  20. I confirm what I said above: it is not this -not yet confirmed- delay by itself what makes things bad. It is the addition of a small series of them.

    Imagine you are a grad student who started in 2003 with the idea of finishing in 2008 with a thesis including enough data to see low-mass SUSY. As the delays pile up, you find your planning fall to pieces, and you are now looking at a thesis plan that will only be concluded in 2010-2011 -if everything else goes well-, when you originally thought you would be a post-doc, with a decent salary, and maybe a life. You are forced to consider bailing out.

    And there are countries where PhD cannot be extended: they last three or four years, period. You started two years ago, and now you know your work will not make a dent, because you will only include Monte Carlo studies in it.

    Further, there are problems with opening new positions for data analysis at LHC: in some countries the delays may end up causing a hole in the time profile of openings.

    I am not a catastrophist: I first of all hope things will not turn out to be as bad as I heard claimed. Second, I think solutions can be found – especially to funding issues, which as far as CERN is concerned JoAnne has well explained aren’t real troublesome. But I insist that the concern is sociological first of all. JoAnne has waited for 20 years, with a salary ? She can wait three more, and we with her. Younger people might be in more trouble.

  21. Peter Woit says:


    Many thanks for the helpful informed comment about the LHC status.

    I agree that the problem with blogs sponsored by the labs or funding agencies is not likely to be censorship, but that the writers may try and avoid anything controversial to avoid embarrassing their sponsors. And, due to their official connection, rumor-mongering is problematic since what the bloggers write will be seen as having some semi-official status.

    On the other hand, with no such connections myself, I’m more than happy to engage in (responsible) rumor-mongering, and encourage informed sources who want to let the rest of the world know what is going on to take advantage of this. Either with their names attached, or not, depending on which is more appropriate…

    And this applies not just to depressing news about delays, etc. If you have information about a new Higgs signal or some-such, that would be even more welcome.

  22. Ellipsis says:

    Hi Peter,

    Thanks. Note that all LHC hardware status info is in principle completely public — you can get all the dirty details at (see especially the nonconformities section). Understanding what is really a big problem and what is more easily fixed requires some detailed knowledge, the vast majority of which I need explained to me as well (and was, thanks to a chain of people). You can bet that I will not be releasing any rumors about the Higgs or any other premature info that is not supposed to be public before release (for good reason). Physics results are fundamentally different than hardware status. When physics results are released they are meant to be definitive statements about nature and the universe. Leaking physics results which may or may not be correct confuses the ultimate goal of teaching the public the workings of the universe. I think that’s something to be avoided. I definitely think Steinberg’s statement (which I saw too) is overly restrictive if he means that they won’t even talk about the most recent hardware status, which is public info. Hopefully his/their self-imposed restrictions will not reduce them to just posting what they had for lunch.

  23. Peter Woit says:


    I had poked around the site you mentioned, surprised to see how much detailed information is available about how the project is going. But I’d also quickly realized that you need an expert to tell you which problems are serious and which aren’t.

    I understand the distinction between the LHC status info and physics results, which are a different question. But even there, I personally don’t see a problem with discussion of rumors of in-progress experimental analyses, as long as this is a discussion aimed at physicists and makes clear that this is work in progress and no claims are yet being made. The tricky part of this of course is the public nature of blogs, which, even when they are aimed at other scientists, are monitored by science journalists who are likely to try and report preliminary results to a wide audience, with the caveats getting sometimes lost in the process.

    Theorists don’t seem to suffer from this problem, with many of them seemingly happy to have highly misleading versions of their work reported, perhaps since the general misfortune of the theorist is to almost never have anyone pay attention to what they are doing. I agree that it wouldn’t be a good thing to have the typical level of New Scientist reporting on theoretical work spread to reporting of experimental results.

  24. Ellipsis – I will never report on my lunch on the US-LHC site (you can check my non-LHC blog for that here)! Of course, I will pass along any substantiated information I come across, but I remain reluctant to pass along non-trivial interpretations of information from anonymous bloggers who heard things from insiders, which was the issue in my Conundrum post.

  25. woit says:


    Just to insist on precision of terminology: if a blogger is someone with a blog, there aren’t any anonymous bloggers involved here. There are anonymous blog commenters, one of whom (Ellipsis, whose identity is not known to me) gives good evidence of knowing what he or she is talking about.

    Other than that correction though, I don’t think there’s anything wrong with your decision not to discuss these rumors on your blog, since it is part of the official LHC outreach effort, and information confirmed by those responsible at the LHC is not yet available. As for the rest of us though, I see no reason not to blog about information coming in either from reliable sources I know the identity of, or credible information from anonymous sources.

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