This Week’s Hype

New Scientist had the good sense to pass on last week’s hype about string theory testability, but is responsible for this week’s hype on the subject, with an article entitled String theory may predict our universe after all. It’s unclear why the article is appearing now, since it is based on a six-month-old preprint from a group at Oxford entitled Triadophilia: A Special Corner of the Landscape.

The authors basically just point out that there are very few known Calabi-Yau manifolds with small Hodge numbers, which thus have a small enough Euler characteristic to give just three generations. They speculate that some unknown dynamical vacuum selection mechanism favors these particular manifolds. In their paper they look only at the topology of the manifolds, so the only “prediction” about our universe is that the number of generations will be small, and this “prediction” is based on assuming an unknown dynamics that favors small numbers of generations.

There has been a huge industry since the late 1980s devoted to trying to extract physics out of the sorts of Calabi-Yaus studied by the Oxford group. This hasn’t gotten very far, with rather elaborate mathematical constructions being used to try and get the quantum numbers of the standard model particles to come out right. One problem with this is that one is not even sure that this is what one wants, since maybe the LHC will find more particles. The groups pursuing this strategy don’t seem to have taken much interest in the Candelas et. al paper, since SPIRES shows that no one has cited it during the last six months.

It looks like 2008 is not going to show any slackening of the promotion by string theorists of bogus “Despite what the critics say, string theory really is predictive!” stories to the press. This one contains quotes from Polchinski that the paper is “neat” and “Maybe it gives us a clue”, and from Strominger that it is “beautiful”. Strominger also minimizes the fact that the Landscape is a problem for string theory, saying:

I don’t think it is incumbent upon string theory to solve the problem of the landscape… If we can’t make the landscape go away, it doesn’t mean that string theory is wrong. It just means it is not a complete solution to all our problems.

Michael Duff says the paper makes “some mathematically sound and interesting observations”, but does note that it doesn’t explain what selects small Hodge numbers, which is about the only slight amount of non-hype that makes it into the article.

Update: As a commenter here points out, the New Year also brings new progress on the scientific investigation of the landscape/multiverse, with a preprint from Don Page about how God loves all universes, not just ours.

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47 Responses to This Week’s Hype

  1. luny says:

    This: http://arxiv.org/abs/0801.0246
    might count as a prediction with some people 🙂

  2. T says:

    Peter,

    I know this isn’t exactly the topic of the post, but can you expand more on the Templeton foundation. I’m a hep-ex and know very little about this, but it appears to be almost an inside attack on science from religion. Is this too harsh?

  3. cwj says:

    The Templeton Foundation doesn’t seek to overturn accepted science, as do the creationists in their various mutations, but to interpret modern science in such a way as to make it “safe” for non-fundamentalist religion, for example, does QM give us free will? Does the unlikeliness of the universe suggest the existence of God? A bit misguided or silly, I’d say, although not as nefarious as the Discovery Institute (some will disagree here): Templeton doesn’t want to attack science so much as to co-opt it.

  4. Coin says:

    The authors basically just point out that there are very few known Calabi-Yau manifolds with small Hodge numbers, which thus have a small enough Euler characteristic to give just three generations. They speculate that some unknown dynamical vacuum selection mechanism favors these particular manifolds.

    Well… okay, never mind the dynamical vacuum selection problem for a minute. Let’s say we just dictate there are three generations, since that’s what experiment seems to indicate, and say that we’re only interested in those string theories that have the appropriate characteristics to get those three generations (small Hodge numbers etc). It’s certainly not a “prediction”, but does this at least significantly cut down on the size of the “landscape”?

    (Assuming the Hodge thing is valid at all, of course? You say there are very few “known” manifolds with this property. They say the number of manifolds with this property “appears to be” small… nobody sounds very confident here.)

  5. alex says:

    “but does this at least significantly cut down on the size of the “landscape”?”

    Sure it does! It has been known for a while that there are very few vacua that are actually relevant for phenomenology. Unless you care about tuning the cosmological constant, the vast landscape of flux vacua is pretty much irrelevant for model building. Lubos and others including Jacques have been saying this all along and for people who actually do computations of sparticle spectra from string compactifications the whole talk about 10^500 vacua bears little significance.

  6. Peter Woit says:

    The number of generations is given by a difference of Hodge numbers, so you can get 3 in lots of ways, using Calabi-Yaus with large Hodge numbers. These authors are suggesting that one only look at ones with small Hodge numbers, which cuts down the number of Calabi-Yaus to look at. I guess with the small Hodge numbers one will also not have exponentially large numbers of flux vacua.

    As far as I can tell, they just completely ignore the problem of the vacuum energy, so all their suggested vacua will have a CC off by more than 100 orders of magnitude. It’s true that if you want to ignore the CC problem you can ignore the huge numbers of flux vacua, and until recently this is what most model-builders were doing. What Lubos has been “saying all along” is that he thinks one should do what these authors do and just ignore the CC problem, Jacques has been saying something different; he has some argument that even if you do use flux vacua to get the CC right, you will not completely use predictivity.

  7. JV says:

    Hi Peter,

    I read so much on what is wrong with string theory on your blog (which by the way is good criticism, so I like refering to this site often); may I then ask just what is right about string theory?
    (In outline form please… I’m no expert on the subject).

    JV

  8. Peter Woit says:

    JV,

    There’s a lot one could say about this, but it is off-topic…

    Very briefly, the two areas string theory has had the most success in are in algebraic geometry, where the topological string allows computations of invariants that are new, and in the study of strongly coupled gauge-theories via a string dual (AdS/CFT). String theory is a huge subject, and there are certainly other interesting things it has led to that can be pointed out.

    It’s really in one main area that it has completely failed, that of providing unification via a 10/11d theory. Unfortunately, this idea was its main selling point, and people are having trouble acknowledging it doesn’t work.

  9. Roger says:

    If the number of generations were, hypothetically, measured to be 10000000, would this then disprove string theory ?

    Its a prediction Jim, but not as we (experimentalists) know it.

  10. alex says:

    “The number of generations is given by a difference of Hodge numbers, so you can get 3 in lots of ways, using Calabi-Yaus with large Hodge numbers.”

    Sure, but only three CY manifolds with \chi=+/- 6 have been found so far after several decades of search.

    “As far as I can tell, they just completely ignore the problem of the vacuum energy, so all their suggested vacua will have a CC off by more than 100 orders of magnitude.”
    In the Heterotic M-theory the tree-level CC can dynamically relax to zero due to a perfect square structure of the potential. There is a cancellation between the flux and the non-perturbative terms when one takes into account the warp factor. The higher order terms may be tuned away as well but I don’t know the details since I’m not familiar with the Heterotic M-theory flux compactifications well enough.

  11. ? says:

    Actually, one of the main issues to think about in studying the “landscape” is that there are local constructions that can easily given three generations, and fit into the manifolds that give exponentially large numbers of vacua. So regardless of whether this is true of the Candelas examples or not, it is quite false that three generations alone cuts the number of models down to a very small number, at least as far as we know at present. Three generations plus much more stringent phenomenological cuts could still reduce the number of models to 1 (or zero), consistent with present knowledge. Several groups (in Germany, at Rutgers and MIT etc) have actually tried to estimate what fraction of models give 3 generations, and their results are consistent with their being many, many such models.

  12. Savage says:

    Don Page’s paper is not science but metaphysical nonsense. Where is the proof of one God loving one universe, forget about the proof of the existence of a muliverse. String theorist Leonard Susskind has now “created” a megaverse which is those worlds in the multiverse which are actualized. What nonsense. I see Page quoted discussions with Dawkins, which I’m sure, totally disagrees with him.

  13. m says:

    by the way, the only reason why the compactification space should be a Calabi-Yau (which is a very peculiar choice) is that many theorists believed that we need N=1 supersymmetry to solve the hierarchy problem. But now the hierarchy problem can be solved without supersymmetry, by invoking anthropic arguments. Calabi-Yau are no longer needed.

  14. luny says:

    Regarding Don Page’s paper, it is not the first time that a physicist dabbled in methaphysics or theology (see Schrodinger or Einstein).

    But the fact that this stuff appears on a PHYSICS PREPRINT site is genuinely new. And its not a sign of progress.

  15. wolfgang says:

    luny,

    > But the fact that this stuff appears on a PHYSICS PREPRINT site is genuinely new.

    worse stuff has been posted.

  16. Yatima says:

    “worse stuff”

    A truly Fortean Link! I never thought that Spontaneous Combustion was connected to Poltergeist Phenomena. Then “sexual neurons” are mentioned. I like it 😉

  17. luny says:

    Yes, but not by a leading physicist with lots of great accomplishments.

  18. JV says:

    Hi again Peter,

    [Sorry for the off-topicness of my previous and current posts], but now that you mention string theory’s main ‘achievements’, may I ask which paper/s are the most important – or groundbreaking, or fundamental – in understanding the above-mentioned topics (technical and/or nontechnical)?

    If string theory is, or is not, really up to the task it claims itself of being able to achieve, i.e. theory unification, may I then (with some skepticism as to its actual viability / realizibility) request the following…

    (occasionally, or if possible, more frequently) Request various expert guests – who agree beforehand to attend – from both sides of the debate – in an ‘e-townhall’ meeting-style format – to present their specific pro- or o- points of views and let the global physics blogosphere ask very probing questions on each point / set of points presented by each, respective, guest.

    This – I think – can go a long way to address your, and likely many others’, concern/s of why string theory is arguably not the promised idea it claims itself to be.

    {Of course, the debate should be *moderated* at all times to keep ad hominem and random attacks to a minimum or (ideally) zero level}.

    Seems like a good idea (in theory at least); but I don’t know if that could be realized when many foremost string theorists don’t seem comfortable taking criticism – or at the prospect of having their research endevours publicly criticized – lightly!
    !! This should be a sufficient reason – 🙂 – to present them with a challenge like this. !!

  19. Wow, Page speaks of “christian cosmologists”… The idea that there are cosmologists whose scientific research is confined and biased by their religious beliefs is disturbing! I thought the era of Teilhard de Chardin was long gone… I am obviously suffering from delusions.

    Cheers,
    T.

  20. Hans says:

    In this paper here:
    http://arxiv.org/pdf/0801.0247
    Don Page even “calculates” the probaability” for “pre death experience” at page 9.

    Why is this stuff accepted on a physics preprint server?

    (more disturbing is, whom he thanks in this crap. Some persons he aknowledges are:

    David Deutsch, Bryce DeWitt, Gary Gibbons, Stephen Hawking, George Ellis, Andrei Linde, Lee Smolin, Bill Unruh, Alex Vilenkin, Steven Weinberg, Paul Shellard, Leonard Susskind, Alan Guth, James Hartle

    (If my name would appear on such “work”, i would take some effort, to get it removed)

  21. anon. says:

    (If my name would appear on such “work”, i would take some effort, to get it removed)

    Those people are (with a couple of exceptions like Smolin) string believers and/or believers in uncheckable ‘multiverse’ interpretations of quantum mechanics and other religions crap.
    That’s probably why Page has cited them. Maybe they helped get his papers endorsed and on arxiv in the first place? 😉

  22. Tony Smith says:

    Hans mentions a few of the people acknowledged by Don Page in 0801.0247 but the list is very long. Also acknowledged there were:

    Sean Carroll
    Mark Srednicki
    Richard Dawkins

    They are of course able to speak for themselves as to how they feel about those acknowledgements ( they were also acknowledged in 0801.0146 ).

    It is interesting that both 0801.0246 and 0801.0247 were among “… a series of lectures sponsored by the Templeton Foundation and given at Shandong University in Jinan, China, autumn 2007 …”.

    I wonder what the Chinese ( who invented gunpowder, the magnetic compass, eyeglasses, etc ) thought of the first sentence of 0801.0247

    “… Modern science developed within a culture of Judeo-Christian theism for several reasons … For example, the idea of a lawgiver for nature (i.e., God) encouraged belief in laws of nature …”.

    Tony Smith

  23. Tony Smith says:

    Sorry about a typo where I put 0801.0146 instead of 0801.0246.

    Also, anon. speculates Don Page getting his “… papers endorsed and on arxiv …”.
    Don Page does not need endorsement of others. The arXiv says:
    “… Don N. Page … Is registered as an author of this paper.
    Can endorse for astro-ph, gr-qc and hep-th. …”.

    Tony Smith

  24. Peter Woit says:

    JV,

    I’m afraid this is off-topic and I’m on vacation, so I’m not going to try and get together references for you. Perhaps someone else here can help. For AdS/CFT, there are lots of review articles, for parts of string theory that have been useful in algebraic geometry, that’s a complicated subject, and what’s worth reading depends both on your background and on what you hope to get out of the material.

    I’d be happy to participate in the sort of debate you describe, but I don’t think you’re going to find many string theorists willing to go along with the idea. Lee Smolin and I both put a lot of effort into carefully putting into words our arguments about string theory, and I think both of us have been discouraged by how little serious response this led to (the two exceptions I can think of are reviews by Aaron Bergman and Joe Polchinski). The lack of this serious response, and a sizable amount of rather appallingly unserious response, has led to the present situation where even string theory partisans write publicly that string theory has lost the public debate.

    The string theorists most likely to want to particpate in an internet-forum debate are those that have blogs, and there are only three active ones that I can think of. Of these, Jacques Distler and Clifford Johnson have explicitly announced that they refuse to read my book or Lee’s. The other one is Lubos Motl.

    I’ve privately talked to many string theorists about these issues, and found that we generally agree on quite a lot, although they’re unwilling to enter into public discussions due to the level of personal hostility they see going on. I’ve heard that many prominent string theorists turned down the opportunity to respond to my book and Lee’s in various publications. My take on all this is that they are well aware that on the central issue here of whether string theory has failed as an idea about unification they know very well that the case for their side is weak, so have decided it is best to keep quiet and hope this blows over, perhaps with the LHC changing the debate in some unknown way.

    By keeping quiet, unfortunately the most sensible string theorists let their field be represented largely by people who are doing a good job of alienating anyone who might be sympathetic to their point of view.

  25. wolfgang says:

    Hans,

    > Don Page even “calculates” the probaability” for “pre death experience” at page 9.

    I wish you and everybody a lot of pre death experience 😎

  26. JV says:

    Hi Peter,

    “Lee Smolin and I both put a lot of effort into carefully putting into words our arguments about string theory…”

    I have a copy of your book – by the way – but to my immediate knowledge it does not contain a list of selected specific references of the sort I was hoping to receive (from you, or otherwise) {… I may be wrong as I don’t have the copy with me while I’m writing this…}.
    [I actually have not completed reading the book in its entireity as yet since many parts are currently beyond my technical understanding; but perhaps as an online Appendix to the work references may prove useful to readers who have the prerequisite background/s.]

    This may help to clear up a great deal of confusion – no doubt much unfavorably brought on by excessive sensationalism from general media sources – regarding the program’s specific and credible merit, and future relevance and prospectives … especially for theory unification.

    If, however, such an attempt fails, I don’t think there is much to be said regarding string theory and the question of its dominance in current hep theory research – it’s here to stay and there’s no point trying to oppose it – whether on scientific or otherwise grounds!

    (I hope that doesn’t occur; my hunch is that many people will only actually take a greater note of your points on string theory’s unviability if you provide a more ‘scholarly-like’ setting to your blog -> book section, even if the general string theory community feels uncomfortable reading / responding to your work directly).

    Hope, anyway, you get the time to reflect upon my proposition once you return to academic duties. Let me know.

    Regards,
    JV

  27. Michael Bacon says:

    “David Deutsch, Bryce DeWitt, Gary Gibbons, Stephen Hawking, George Ellis, Andrei Linde, Lee Smolin, Bill Unruh, Alex Vilenkin, Steven Weinberg, Paul Shellard, Leonard Susskind, Alan Guth, James Hartle”

    “Those people are (with a couple of exceptions like Smolin) string believers and/or believers in uncheckable ‘multiverse’ interpretations of quantum mechanics and other religions crap.”

    Hans and Anon. You guys have to be kidding, no? When you guys contribute half of the “crap” these folks have, then maybe you’ll be secure enough of your status in the scientific community not to worry about whether you are revealed to have had conversations with other (albeit goofy) researches, even if you don’t agree with much of what they have to say.

    Peter, I agree with you generally regarding the failure of the string theory project to acheive its stated objectives, but please don’t encourage this type of know-nothing behavior by ignoring it. Thanks.

  28. Hans says:

    Michael Bacon wrote: Hans and Anon. You guys have to be kidding, no?

    Well,
    The persons whom Don Page thanks must indeed not worry about their status. But that is not the problem.

    With his long list, to whom Page thanks to, he wants to create the impression that he has discussed such topics among the leading figures of the physics community and therefore, this stuff is acceptable to a physics preprint server.

    So, the people who are listed there are, in some sense, a support for this crap. Don Page might have put them in their paper without even asking them.

    The problem is not, that Steven Weinberg and others would have to fear about their status. Thats certainly not the case.

    The problem is, that in a true world, leading figures should take pains, not to appear in such pseudoreligious crap. They should distance themselves from this paper forcefully.
    They should make clear, that the opinions of Don Page are minority opinions, having nothing to do with physics or science at all and should ask arxiv to remove this crap.

    I hope there is nobody out there, who wants more papers like this on arxiv org (maybe with more “supporters” listed to).

  29. Chris W. says:

    While the appropriateness of Don Page’s preprint on arXiv.org might well be questioned, given its theological content, I think it should be acknowledged that it is not bad as these things go. Page is a committed Christian, but he is also a first-rate physicist. His arguments are hardly comparable with the kinds of evasions typically indulged in by ID advocates (never mind creationists). The paper’s preface specifically addresses the question of appropriateness to the arXiv.

    By the way, Page’s undergraduate alma mater, William Jewell College, is an interesting place. (Donald Marolf is another of its graduates.) Four years ago the college lost the financial support of the Missouri Baptist Convention, with which it had a longstanding connection, because it stood up to a challenge by the MBC of the College’s teaching of evolutionary biology.

    Leaving aside the theology, the paper does not offer much reassurance to those who regard the putative existence of the multiverse as a horrendous epistemological can of worms for scientific cosmology and physics itself.

  30. Peter Woit says:

    About the Page paper and its acknowledgements.

    Perhaps the hep-th moderator had the good sense to at least insist that it couldn’t be posted there if that’s where it was originally submitted.

    I don’t think you can make people responsible for the content of papers in which they are thanked, but in this case, many of those thanked are among those promoting anthropic pseudo-science. It continues to surprise me how few prominent people in this subject are willing to publicly criticize this kind of nonsense in any way. David Gross is one of the few examples I can think of. The problem is not so much a few serious theorists posting obviously silly preprints on the arXiv, arguably anyone who has done serious work in the past should be allowed to make a fool of themselves at least a couple times. The problem is the increasing infiltration of the field by pseudo-science, as almost everyone tolerates an ever-increasing level of it without comment.

  31. Michael Bacon says:

    “The problem is, that in a true world, leading figures should take pains, not to appear in such pseudoreligious crap. They should distance themselves from this paper forcefully. They should make clear, that the opinions of Don Page are minority opinions, having nothing to do with physics or science at all and should ask arxiv to remove this crap.”

    Hans, I guess these folks, notwithstanding their other accomplishments, just don’t have your keen sense of intelligence when it comes to how they should behave when asked to discuss certain limited scientific issues by a fellow scientist (even one that’s a little nuts). Hopefully your clear sighted comments on how to treat these types of situations will become more widespread. What a much better place the scientific world will be when we can finally be rid of the misbehavior of Hawking, Deutsch and their ilk. 🙂

  32. Coin says:

    The number of generations is given by a difference of Hodge numbers, so you can get 3 in lots of ways, using Calabi-Yaus with large Hodge numbers. These authors are suggesting that one only look at ones with small Hodge numbers

    Hm, okay, that answers at least one of my other questions. Do you mind if I poke at this a bit more? (I’ll admit upfront that I’m only asking because I think their diagram on page 4 of the PDF is real pretty, and I’m curious what it means.)

    What exactly is a Hodge “number”? I am having trouble finding a clear definition on that. The closest I can find are the dual explanations of this:

    The Hodge number is the analog of the Betti number on real manifolds for complex manifolds.

    and this:

    the Betti number of a topological space is, in intuitive terms, a way of counting the maximum number of cuts that can be made without dividing the space into two pieces.

    This defines, in fact, what is called the first Betti number. There is a sequence of Betti numbers defined… the k-th Betti number… of the space X is defined as the rank of the… k-th homology group of X

    Hm, okay, but why do you need two indices to identify a Hodge number, and why are the only indices the Triadophilia people are interested in h^11 and h^21?

    Is there some kind of “intuitive” explanation of the Hodge numbers, or h^11 and h^21 in specific, analogous to the “cuts” explanation for the first Betti number?

  33. Peter Woit says:

    Coin,

    Calabi-Yau manifolds are complex (Kahler) manifolds, and in such a situation the cohomology, instead of being graded by a single number is graded by a pair of numbers. The easiest way to see this is using the deRham model of cohomology, where the n-th Betti number is the dimension of the space of differential forms of degree n that are harmonic (Laplacian on them gives zero). If you have a complex manifold that is Kahler, such differential forms break up according to the number of dz’s and dz-bar’s in the differential form of total degree n. For the details of this stuff, you really need to consult a book on complex manifolds, Chern’s short one is relatively readable.

  34. Peter Woit says:

    King Ray,

    Yup, that’s it.

  35. Coin says:

    Thanks Peter/Ray, that helps a lot.

  36. King Ray says:

    Peter, thanks. I don’t think I have that one, so I may pick up a copy.

    Kind of an odd title, “Complex Manifolds WITHOUT Potential Theory.”

    Maybe some string theorist should write a book titled “String Theory WITHOUT Testable Predictions.”

  37. King Ray says:

    Coin, you’re welcome. I was curious to see the book recommended by Peter so I looked it up on Amazon.

    The formulas for the connection and curvature tensors are so much prettier and simpler on complex manifolds.

  38. Xerxes says:

    Three is small now? I’ve been talking to large-Nc people, and they tell me that three is approximately equal to infinity. I guess three is a small number of generations, but a large number of colors. Is it a large or small number of spatial dimensions?

  39. Matteo Martini says:

    If I can, I would like to ask a question to Peter Woit and all the people who maybe interested to reply to me.

    I admit this question is a small derail from the topic, but I would like to have the question written here, rather then ask the question by Email to any of the posters.
    I ask pardon to Peter for that.

    I would like to know if you think there is any future for particle phyisics after the current state of knowledge.
    As far as I have understood, after the LHC will go online in the summer of this year, there will be no other plans of building more powerful accelerators (as the ILC simply adds luminosity, but not more electron volts).

    Since most part of the human progress in the last 50-100 years has been done in fields such as electronics, semiconductor industry, biochemistry and related (informatics, pharma ), etc, which are more or less related to advancement in basic physics done in the last 50 years or more, I do not think it is baseless to say that, once we will hit the wall in the current progress in quantum physics (have we already hit that wall?) we will also (sooner or later) hit the wall in finding new ways to progress our knowledge in many fields, with this potentially ending human progress forever.
    Without new and more powerful accelerators coming online after the LHC, it may be that new theories after the standard model could not be written as there will be no accelerator powerful enough to provide the necessary data/testing conditions.

    Am I the only one to think this?
    Again, sorry for the derail and for lowering the average technical level of the comments of this thread.

  40. chris says:

    hi matteo,

    if we knew what the lhc would show us, we would not even need to switch it on. maybe there is no future for large collider rings. but there is also some natural limit to refractor lense sizes, which was reached about 100 years ago. still this was not astronomys death. we’ll just have to wait and see.

  41. DB says:

    Matteo,
    It’s quite a big derail from the topic, but if Peter will undulge me I’ll give you some pointers.
    Be sure of one thing, the LHC will fundamentally alter our picture of particle physics. It will give us a much clearer idea of the merits of the Higgs mechanism and supersymmetry and this will be crucial for future theoretical and experimental progress.

    The ILC is dead, flavor physics has been dealt a serious blow with the axing of BaBar, and the US is not interested in building a successor to the LHC on its territory. It will continue to participate heavily in particle astrophysics but even here NASA is under great budget pressure. If NASA pulls the plug on particle astrophysics, the European Space Agency will help plug the gap.

    Future particle accelerators will not be planned until the LHC delivers its results, and if they are built the effort will be led by CERN, and, for cost reasons, will have to be a globally funded project, as with ITER. The US may well decide to participate financially. It’s a long way off, but we have waited 30 years between LEP and the LHC (pace the excellent work done at the Tevatron) and we have learned to be patient. Remember also that there is more to HEP than the LHC and its successor. The most significant advances in HEP in recent years (neutrino mass/oscillation and the solution of the solar neutrino problem) have come from modest neutrino experiments in Canada (Sudbury) and Japan (Kamiokande).

    We have not hit the wall in quantum physics, far from it. If you check the LCLS project at SLAC and its equivalent XFEL at DESY you will discover how rich are the prospects for useful advances in this area in return for comparatively modest expenditures, although the fact that two machines are being built tells me that HEP still hasn’t learned its lessons with regard to needless duplication of effort.

    As the ISS has shown, the only viable model in the future for big science is a global one and I have no doubt that we will see plenty of exciting developments along these lines in the years to come.

    Be of good cheer, we are nowhere near the end of this game.

  42. Matteo Martini says:

    DB,
    thanks for your explanation.
    Again, sorry for the derail.

    Matteo

  43. J.F. Moore says:

    Just a note on DB’s comment: LCLS and XFEL are not HEP projects. In fact, SLAC is now administered as a BES lab, in recognition of where the bulk of their funding is coming from. These two machines are also being created as user facilities, so even if they had identical photon beam properties (they don’t), having one on the same continent is a big plus for a ‘user’, which in practice can be a small academic group with travel funds.

    My side-advice to Matteo is to get out there and talk to people, read their papers and see what moves you. Eventually it becomes clear what you must do.

  44. chris says:

    DB,

    as j.f. moore remarked, lcls and xfel are no hep projects. xfl once was a sideline of the ilc-predicessor tesla. tesla is dead now, and its hosting lab, desy, is also transforming from a hep into a material science lab. so this particular game was lost by hep.

  45. WiCoB says:

    What I found interesting in the NewScientist was a subtle manipulation of figure captions and suggestions of something mysterious in the triangular shape of the plot of known C-Y manifolds. I am not sure if it is still within reasonable scientific journalism, or if the hunt for news item has gone too far this time?

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