A Few Quick Items

I’ve had little time for blogging, and coincidentally, there seems to be little to blog about recently. Here though are a few quick items:

  • Several people had asked me about this paper about the CC, and I had to tell them that this was not something I could evaluate. Luckily, Sabine Hossenfelder has read it and thought about it carefully, and discusses the problems with this sort of thing here. The physics community owes her a great debt.
  • The LHC is back in business, with intensity starting to ramp up. You can follow progress here. This summer should see release of more results based on last year’s run, results from this year’s run likely will not appear until early next year.
  • Inference magazine has a thoughtful piece in the latest issue by Adam Falkowski (AKA Jester) about prospects for the future of HEP physics. The same issue also has a piece by Aurélien Barrau about the implications of the failure to find the “natural” physics some expected SUSY to provide.
  • Hironaka has recently put on his website a document intended to give a proof of resolution of singularities in characteristic p. For some background and links to explanations of what this is about, see mathoverflow. Evidently Hironaka has been working on this proof for quite a few years, this is the first complete version to be made public. Sometime in the next few months it should become clear whether this proof will really work, as experts get a chance to go through it carefully. If it does work, it will be a remarkable story, especially since Hironaka is now 86.
  • Maybe I’m the last one to find this out, but for quite a few years now MIT has been making public detailed course materials including lecture notes from many courses in mathematics and physics.

Update: For the obligatory Multiverse Mania item, see this interview with Lord Martin Rees. Rees is rather proud of himself for leading the field of theoretical physics to embrace Multiverse Mania, quoting Frank Wilczek as claiming at the end of a conference that:

five years ago we were a beleaguered minority, whereas now, he and I and others had led many other people into the wilderness.

Besides his belief in the multiverse, he also believes this is what we have in our future:

I don’t think Elon Musk is realistic when he imagines sending people a hundred at a time for normal life because Mars is going to be far less clement than living at the South Pole, and not many people want to do that. I don’t think there will be many ordinary people who want to go, but there will be some crazy pioneers who will want to go, even if they have one-way tickets.

The reason that’s important is the following: Here on Earth, I suspect that we are going to want to regulate the application of genetic modification and cyborg techniques on grounds of ethics and prudence. This links with another topic I want to come to later about the risks of new technology. If we imagine these people living as pioneers on Mars, they are out of range of any terrestrial regulation. Moreover, they’ve got a far higher incentive to modify themselves or their descendants to adapt to this very alien and hostile environment.

They will use all the techniques of genetic modification, cyborg techniques, maybe even linking or downloading themselves into machines, which, fifty years from now, will be far more powerful than they are today. The posthuman era is probably not going to start here on Earth; it will be spearheaded by these communities on Mars.

: Another black hole merger detection from LIGO announced today, some commentary here and here.

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10 Responses to A Few Quick Items

  1. JohnA says:

    The Falkowski article criticizes the future collider program (100 TeV pp) for:
    -) lack of clear physics target
    -) required monetary/time investment

    He instead advocates for more cheaper, faster indirect searches.

    One major (and obvious) thing his article/argument misses is the intermediate Higgs factory step in the path for a ~100 TeV pp collider.
    This is major piece of the program for both of the proposed next generation ~100 TeV colliders (CERN/China).

    Compared to his 100 TeV straw-man, the Higgs factory is a cheaper, faster indirect search with a clear and obtainable physics goal; order of magnitude, or better, improvement on higgs coupling measurements.
    It also has the advantage of being able to be recycled into a 100 TeV machine if it indirectly sees signs of new physics or we find a convincing argument for 100 TeV in the mean time.

    The decision is not 100 TeV or a bunch of indirect measurements. If there is choice to argued over, the option the future collider program is: Higgs-factor + future option on 100 TeV. Falkowski’s discussion largely irrelevant as it completely neglects this real choice.

  2. Peter Woit says:

    The problem is that a Higgs factory isn’t cheap. The Higgs factory proposals involve the same huge tunnel as for the 100 TeV machine. The cost of the tunnel + ee machine + detectors I would think would be a significant fraction of the cost of the 100 TeV machine. I haven’t seen cost estimates for either the FCC-ee or FCC-pp, but these are going to be very large numbers, and that’s the problem.

    Actually I think one motivation for the FCC-ee is to divide the FCC-pp cost into two pieces and spread it out over a longer time. It’s not at all clear the FCC-ee would be worth it if the plan was just to build it and then stop, rather than go on to the pp machine.

  3. Bee says:

    Thanks for the link. (That paper caused me quite some headache.)

    Isn’t it funny how much the two inference pieces sound like this blogpost I wrote last year?

  4. vmarko says:

    Regarding the latest CC-problem-solving paper — it seems to me that the CC problem is a social problem, rather than a physics problem. Namely, every now and then there appears a new paper proposing yet another resolution of the CC problem, so much that by now almost every hep-th physicist has their own favorite solution (myself included). And while all these papers offer worthwhile insights into the CC problem and interesting ways to resolve it, none of them produces a “Wow!” moment from the whole community, and most of the proposals end up being anticlimactic in one way or another.

    At best, some part of the hep-th community (slightly larger than just the paper authors) will get excited about any particular proposal, while others will find it unsatisfactory on various grounds (mostly aesthetic), and over time everyone forgets about it until the next proposal comes along.

    I don’t see this paper being any different, except for a big name like Unruh making it more likely to catch some wider attention.

    Everybody is waiting for a paper which will make the whole community say “Oh, look, this is how it should be answered, we were all so dumb, but now it’s so obvious!”. However, such a paper will never appear — not because existing proposals aren’t convincing enough, but because the people in the hep-th community have various (often contradicting) ideologies, and they will never agree on which solution is satisfactory.

    So the CC problem is a social problem, unlikely to ever converge to a consensus solution, no matter how ingenious proposals people offer.

    Best, 🙂

  5. Anon says:

    Adam writes in his article:

    “The possibility that the LHC will only further confirm the Standard Model is often referred to as the nightmare scenario”

    I’ve never understood this pessimism from the physics community. The fact is, a new particle has been discovered in the Higgs, and the LHC will increasingly probe its properties over the next two decades. If nothing is found, theoretical physicists will just need to accept the completion of the periodic table for elementary particles is possibly in the distant future, as was done for the periodic table of elements recently:


  6. Low Math, Meekly Interacting says:

    It’s hard to install your own cybernetic implants and kiss the Singularity when you’re suffering from cosmic-ray-induced dementia. I don’t think even crazy pioneers are going to be interested flying all the way to Mars only to live underground the great majority of the rest of their significantly shortened lives.

    Multiverse mania seems to be a more general syndrome than its name would suggest.

  7. Andre T says:

    A Higgs factory would likely be e+ e- machine. For a a 125 GeV higgs, the production cross section is around root(s) = 250 GeV or so. (To measure Higgs BRs, gauge boson couplings). Quartic coupling is optimally measured at around 450 GeV, IIRC.
    The t-tbar threshold is 350 GeV. Worth spending some luminsity there as well

    This is a very viable 30 year program for a upgradeable linear collider whose cost compared to a 100 TeV machine would allow pushing the precision frontier simultaneously…

  8. Peter Woit says:

    Andre T,
    The problem with a Higgs factory linear collider is the same problem as that of a circular collider in a 80-100km tunnel: estimates of the total ILC cost come to about $20 billion, a very big number (the yearly power costs would also be high).

    The linear collider would have the advantage that you could imagine upgrading it to higher energy, the circular collider would have the advantage that you could reuse the tunnel for a 100TeV pp machine.

    There are good arguments to be made for either possibility, and the ideal thing for physics would be to build both. The basic problem though is that of how to pay for such a thing.

  9. Dave MIller says:

    Peter wrote:
    >Maybe I’m the last one to find this out, but for quite a few years now MIT has been making public detailed course materials including lecture notes from many courses in mathematics and physics.

    Peter, I’ll add that my kids worked through, with my help, Anant Agarwal’s “Circuits and Electronics” (edX 6.002X) and Christ Terman’s “Computation Structures” (6.004X). Both courses are online videos, homework, and exams, not just course notes (Agarwal’s is videos of him lecturing, Terman’s is more of a PowerPoint-like format with audio of Terman speaking).

    Terman is a very good teacher. Agarwarl, who is apparently the moving spirit behind the MIT series of courses (which has now become edX), is a truly brilliant teacher, in my opinion in the same league as Feynman (I took a couple of classes from Feynman as an undergrad).

    Any physicist who expects to end up doing electronics (and many will after going out into the real world) should consider going through these courses. And, we should urge any bright high-schoolers we know also to work through some edX courses.

    MIT, and especially Anant Agarwal, have really made a great educational breakthrough with these online courses.

    Dave Miller in Sacramento

  10. Jakob says:

    The arguments and conclusion by Adam Falkowski immediately reminded me of “Six cautionary tales for scientists” by Freeman Dyson from 1988. Dyson compares 6 situations where people had to decide between a Plan A = several small projects vs. a Plan B = one huge project.

    He discusses the SCC (” an extreme example of Plan B”) and concludes: “My Plan A for the future of particle physics is a program giving roughly equal emphasis to the three frontiers. Plan A should be a program of maximum flexibility, encouraging the exploitation of new tools and new discoveries wherever they may occur. To encourage work on the accuracy frontier means continuing to put major effort into new detectors to be used with existing accelerators. To encourage work on the rarity frontier means building some new accelerators which give high intensity of particles with moderate energy. After these needs are taken care of, Plan A will still include big efforts to move ahead on the energy frontier. But the guiding principle should be: more money for experiments and less for construction. Let us find out how to explore the energy frontier cheaply before we get ourselves locked into a huge construction project.”

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