Not Ever Wrong

The “SUSY Bet” event in Copenhagen took place today, with video available for a while at this site. It appears to be gone for the moment, will put up a better link if it becomes available. An expensive bottle of cognac was presented by Nima Arkani-Hamed to Poul Damgaard, conceding loss of the bet. On the larger question of the significance of the negative LHC results, a recorded statement by Gerard ‘t Hooft (who had bet against SUSY), and a statement by Stephen Hawking (not in on the bet, but in the audience) claimed that if arguments for SUSY were correct, the LHC should have seen something, so they think nature has spoken and there’s something wrong with the idea.

The losers of the bet who spoke, (Arkani-Hamed, David Gross and David Shih) demonstrated the lesson about science that supersymmetry and superstring theory have taught us: particle theorists backing these ideas won’t give up on them, no matter what. They all took the position that they still weren’t giving up on SUSY, despite losing the bet. In more detail:

  • Arkani-Hamed was not a signatory of the original bet in 2000, but signed on to the later 2011 version. He explained today that at the time he thought chances of SUSY visible early on at the LHC were just 50/50 (with his 2004 work on split SUSY motivated by realizing that pre-LHC the conventional picture of SUSY at the electroweak scale was already ruled out). He attributed his decision to take the pro-SUSY side of a 50/50 bet to “optimism”, implying that this took place at a conference dinner where there may have been too much to drink. In his split-SUSY scenario, SUSY may yet show up at the LHC, or it could even be invisible there, requiring a higher energy accelerator. So, he’s not giving up on SUSY based on LHC results.
  • David Gross also is not giving up, arguing that fine tuning of a factor of 100 or 1000 is not a problem (invoking the large ratios that appear in the fundamental Yukawa couplings). He did say that young people might want to take this as reason to look for new ideas, but, for himself, felt “I’m too old for that”.
  • David Shih isn’t giving up either, arguing that there still was lots of data to come, plenty of room for SUSY to appear at the LHC, still believes we’ll discover SUSY, at the LHC or elsewhere.

One piece of misinformation promoted by several of the speakers was the idea that “everyone” back around 2000 believed in SUSY as the next new physics to be found. In my book (written in 2002-3) I wrote a long section about the evidence against SUSY, and, of course, if you look at the bet under discussion, in 2000 many more people (16 vs. 7) were taking the anti-SUSY vs. pro-SUSY side (at least in Copenhagen, but I think this reflects the general range of opinions).

No one today asked the obvious question “Is there any forseeable experimental data that would cause you to decide that SUSY was an idea that should be abandoned?”. I’m now not seeing any prospect in my lifetime of anything that would cause these or other SUSY proponents to give up (John Ellis has also announced that no matter what the LHC says, he’s not giving up). Unfortunately “Not Ever Wrong” is clearly the slogan of the (minority) segment of the particle theory community that long ago signed up for the vision of fundamental physics in which SUSY plays a critical part.

Update: There’s a blog entry from Natalie Wolchover about this. She has more detail about the final remarks from Gross that I mentioned:

“In the absence of any positive experimental evidence for supersymmetry,” Gross said, “it’s a good time to scare the hell out of the young people in the audience and tell them: ‘Don’t follow your elders. … Go out and look for something new and crazy and powerful and different. Different, especially.’ That’s definitely a good lesson. But I’m too old for that.”

Update: Video of the Copenhagen event is available here.

Update: I happened to be looking at Michael Dine’s 2007 Physics Today article on string theory and the LHC, noticed the side remark that “The Large Hadron Collider will either make a spectacular discovery or rule out supersymmetry entirely.” I wonder if he still thinks this, and whether we’ll ever see Physics Today publishing something updating its readers.

Update: Yet another news story about this, from Science News.

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106 Responses to Not Ever Wrong

  1. Low Math, Meekly Interacting says:

    FWIW, I have many middle-aged colleagues who grew up in mainland China. None of them have a physics background beyond the requirements to get their degrees in other areas, like medicine or biochemistry. They all know who C.N. Yang and T.D. Lee are and can tell you in impressive detail what they shared the Nobel for, K mesons, parity violation, the whole deal. If I ask one of my contemporaneous American colleagues who our most famous physics laureate is, I would likely get an answer like “um…Einstein?” (technically correct, but…) For reasons I don’t claim to fully understand, these Chinese folks had it drilled into their heads during their pre-graduate educations that Lee and Yang were exemplars of Chinese civilization, and are worthy of reverence. If Yang is going around saying SUSY is a waste of time and money, I’d guess it would exert oversized influence, at least on the generation that now is predominantly represented in the Party of the PRC.

  2. GoletaBeach says:

    As I said, in the sentence prior to the one you quote in the Dine article, he points out a good reason to be skeptical of SUSY… “Despite those successes, good reasons exist for skepticism. Some are experimental: Apart from coupling unification, no direct evidence yet argues for supersymmetry.”… yes, his subsequent sentence that LHC will be deterministic for SUSY is simply wrong, and in no way (ever) represented the consensus view of the experimental community. And was not a sufficient portion of the article to warrant a retraction, in my opinion.

    The Fabiola Gianotti and Chris Quigg article that same year is much closer to the consensus view of the community.

    I don’t think any of the LHC technical documents (yellow books, technical design reports, etc) say anything like ““SUSY will either be discovered at the LHC or is wrong”. If you know of anyplace those documents support your assertion, I’m all ears.

    Everyone serious knows that even the simplest implementations of SUSY, like the CMSSM, are not close to eliminated by LHC data. See for example, Leszek Roszkowski’s talk at IDM 2016: https://idm2016.shef.ac.uk/indico/event/0/timetable/#20160719.

    Any claim that “SUSY is wrong” is not currently supported by data or phenomenology. Pointing to a few people who said that is sort of like pointing to a few glaciers that are expanding and claiming that global warming is wrong.

    Do any theorists, whether Gordon Kane or Frank Yang, have any significant credibility with their predictions? Einstein himself was wrong about a lot, from the cosmological constant to quantum mechanics, and he was even childish and petulant in his errors about gravity waves, as Barry Barish has been pointing out in his recent talks.

    The mistake is ever to attribute credibility *for sweeping predictions* to theorists. If they can bat 0.001 that actually an amazing record on the “big questions”. Batting 0.300 has never been realistic.

    I think the mistake is to get snide and dark over the 0.999 of the time theorists are wrong about big stuff. Because… first of all, it is too easy, it is like shooting fish in a barrel. Second of all, being snide and dark only suppresses the speculation that is necessary for the occasional right theoretical idea to pop up.

  3. Peter Woit says:

    GoletaBeach,

    The Frank Yang problem I was pointing was not bad predictions from him, but he’s a good example of the danger you face when you choose to overhype an idea about physics (and lots of people did this with SUSY and the LHC, not just Dine and Kane). Serious physicists like Yang will notice you’re doing this, and after your “predictions” don’t work out, and you try and pull the same thing again, they’ll call you on it. And some of them may be extremely influential with the government officials you need funding from.

    By the way, there’s yet another news story about this

    https://www.sciencenews.org/article/supersymmetry%E2%80%99s-absence-lhc-puzzles-physicists

    I’ll add an update to the posting.

  4. GoletaBeach says:

    Nice Science News article… actually the Frank Yang comment has harmed his reputation with me, now that I look carefully at it. I am getting repetitive, but if you choose a subset of the community (say, Kane, Dine, some others you bring up) and then color everyone with their comments, *and*, if you ignore the measured consensus documents like all the technical design reports, yellow reports, Snowmass process, etc…. well… you are doing the same thing climate deniers do.

    Maybe climate deniers are in the end correct, but their application of the scientific method is unconvincing.

    Building the highest energy machine is always a good scientific idea. In fact we have learned that the SSC had more discovery potential than the LHC, ex post facto (I know you didn’t want any more collider discussion, but you reintroduced with Frank Yang’s comment about the Great Collider).

    The only issue is cost. If we could do 100 TeV for the cost of the LHC, we should do so, independent of SUSY or technicolor or multiverses or any theoretical fashion.

    Because discovery is an empirical science in the end. But the LHC cost has been a kind of wall that governments cannot get beyond, maybe fairly.

    If Frank Yang is anti-discovery, well, his reputation suffers with me.

  5. Peter Woit says:

    GoletaBeach,

    I agree that a new energy frontier machine is desirable. My only point is that if you try and make the case for it with the argument “a 100 TeV collider will tell whether or not there is SUSY” (I’ve already seen this argument made publicly, in this form, will see if I can remember the source), you’re handing over to those who disagree with you excellent evidence that you lack credibility.

  6. GoletaBeach says:

    Sure, there are always people who overstate the case for anything… most politicians, most fitness gurus, some scientists.

    For the LHC, the serious case was made in DOE technical design reports, CERN yellow reports, etc. I don’t think you’ll find a statement like “the LHC will either confirm or refute SUSY” in any of those reports, but if you can point to an example, I’m interested in knowing. Quigg and Gianotti in their 2007 Physics Today seem to me to have respected the foundational LHC reports, and Dine did not.

    Similarly for any serious 100 TeV proposal… there will be lots of careful scientific projection and effort that will be documented very responsibly, and that is the corpus of work that will form the foundation of the proposal.

    I’m not comfortable with replacing all that good science with the overenthusiastic or exaggerated claims of some theorists, or some promoters, or whoever. Maybe in the superficial media world things like that happen all the time… the glib talking heads get to drive the bus.

    At least within the world of science, the real science should matter. However, there is freedom of speech and opinion… if Nima Arkani-Hamed or David Gross or Gordon Kane or Michael Dine wants to try to give their personal spin, I see no way to stop them.

    Well, maybe if China chooses to build the collider they could imprison anyone saying something not consistent with all the design reports…. China certainly does that on other political issues. I’m not being serious, of course.

    Even if China did that, any talking head with an opinion could always just hide out in the Ecuadoran embassy and Skype their opinion to the world (not serious about that either).

    In the end Hollywood rules are probably about as practical as anything: 1)if your name gets publicized, your first concern should be if they spelled it right, not what the nature of the publicity is; 2)the only bad publicity is your obituary.

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