## Sunday, June 19, 2016 ... /////

### Ambulance chasing is a justifiable strategy to search for the truth

As Ben Allanach, a self-described occasional ambulance chaser, described in his 2014 TRF guest blog, ambulance chasers were originally lawyers with fast cars who were (or are) trying to catch an ambulance (or visit a disaster site) because the sick and injured people in them, potential clients who may have a pretty good reason to sue someone and win the lawsuit. For certain reasons, this practice is illegal in the U.S. and Australia.

Analogously, in particle physics, ambulance chasers are people who write many papers about a topic that is hot, especially one ignited by an excess in the experimental data. This activity is thankfully legal.

The phrase "ambulance chasing" is often used pejoratively. It's partly because the "ambulance chasers" may justifiably look a bit immoral and egotistically ambitious. However, most of the time, it is because the accusers are jealous and lazy losers. Needless to say, it often turns out that there are no patients capable of suing in the ambulance which the critics of ambulance chasing view as a vindication. However, this vindication is not a rule.

The probability to find clients is higher in the ambulances. It's similar as the reason why it's a better investment of money to make Arabs strip at the airport than to ask old white grandmothers to do the same – whether or not some politically correct ideologues want to deny this obvious point.

Is it sensible that we see examples of ambulance chasing such as the 400 or so papers about the $750\GeV$ cernette diphoton resonance?

It just happens that in recent 2 days, there were two places in the physics blogosphere that discussed a similar topic:

An exchange between 4gravitons and Giotis

Game of Thrones: 750 GeV edition (Resonaances)
It seems rather clear that much like your humble correspondent, the first page is much more sympathetic to the ambulance chasing episodes than the latter one.

My conservative background and that of a formal theorist make me a natural opponent of ambulance chasers. If I oversimplify this viewpoint, we're solving primarily long-term tasks and it's a symptom of the absence of anchoring when people chase the ambulances. For example, quantum field theory and string theory will almost certainly be with us regardless of some minor episodes and discoveries and that's why we need to understand it better and we should pay too much attention to some "probably" short-lived fads.

However, the more experiment-oriented parts of particle physics – and even the theoretical ones – are sometimes much more dependent on an exciting breakthrough. Some developments may look like short-lived fads at the beginning but they actually turn out to be important in the long run. A subfield suddenly grows, people write lots of papers about it and they may even switch their fields a little bit. Is that wrong? Is it a pathology?

I don't think so.

As Giotis and Tetragraviton agreed in their discussion, the size of the subfields of string theory (or any other portion of physics research) changes with time. The subfields that recently experienced a perceived "breakthrough" grow bigger. Is that immoral?

Not at all.

It simply means that people appreciate that some methods or ideas or questions have been successful or they have demonstrated that they could be a route to learn lots of new truth quickly. And because scientists want to learn as much of the truth as possible, they naturally tend to pick the methods that make this process more efficient. It's common sense. There seem to low-hanging fruits around the breakthroughs and people try to pick them. As they're being picked, the perceived density of the fruits may go down and the "fad" may fade away.

So string phenomenology was producing a huge amount of papers for a few years after some amazing progress took place in that field. Similarly, the AdS/CFT correspondence opened a whole new industry of papers – the papers that study quantum field theories using "holographic" methods. AdS/CFT came from Maldacena's research of formal string theory and the black hole information puzzle. These two interrelated subfields of string theory have actually produced several other subindustries, although smaller than the holographic ones. The word "subindustry" is a more appropriate term than a "minirevolution" for something that the cynics call a "fad", especially when this "fad" continues to grow for 20 years or so.

The ability of formal string theory to produce similar breakthroughts is arguably still being underestimated.

At any rate, a part of the dynamics of the changing relative importance of subfields of fundamental physics – or string theory – is certainly justifiable. I don't want to claim that people study things exactly as much as they should – I have often made it clear that I believe that such deviations from the optimum exist, most recently in the previous short paragraph ;-) – but most critics generally misunderstand how sensible it is for people to be excited about different things at different times. Many critics seemingly believe that they are able to determine how much effort should be spent with every thing (such as A, B, C) even though they don't understand anything about A, B, C. But that's nonsense. You just can't understand how big percentages of time physicists spend with various ideas if you don't know what all of these ideas are.

At Resonaances, Adam Falkowski is basically making fun out of the people who have written many papers about the $750\GeV$ diphoton resonance. With this seemingly hostile attitude to resonances, you may think it's ironic for the blog to be called Resonaances. But maybe the word means Resona-hahaha-ances, i.e. a blog trying to mock resonances.

The top contestants have a similar output as Alessandro Strumia – some 7 papers on the topic and 500 citations. A paper with 10 authors from December 2015 has over 300 citations now. If they had to divide the citations among the co-authors, it wouldn't be too many per co-author.

Clearly, physicists like Strumia are partially engaging in an activity that could be classified as a sport. But is that wrong? I don't think so. Physics is the process of learning the truth. We often imagine theoretical physicists as monks who despise things like sports and by my fundamental instincts, I am close enough to it. But the "learning of the truth" isn't in any strict way incompatible with "sports". They're just independent entities. And sports sometimes do help to find the truth in science.

I would agree with some "much softer and more careful" criticisms of ambulance chasing. For example, in most such situations, the law of diminishing returns applies. The value of many papers usually grows sublinearly with their number which is why most "fads" usually fade away. The value of 7 papers about the resonance is probably smaller than 7 times the value of a single paper about the resonance. First, there is probably some overlap among the papers. Second, even if there is no overlap, many of the "added" papers are probably less interesting because the author knows which of the ideas are the most promising ones, and by writing many papers, he or she probably has to publish the less promising ones, too.

So this activity may inflate the "total number of citations" more quickly than the underlying value of the physical insights. At the end, the number of citations that people like Alessandro Strumia have accumulated may overstate their overall contributions. But they don't really hysterically fight for the opinion that it doesn't. They just do science – and a lot of it. It's up to others who need the number to quantify the contributions.

At the end, I still find it obvious that in average, it's better when a physicist writes 7 papers about a topic than if he writes 2. The results vary and 1 paper is often more valuable than 10,000 other papers. But if one sort of imagines that they're papers at the same level, 7 is better than 2. So it's not reasonable for Falkowski to mock Strumia et al. Needless to say, if the resonance goes away, Falkowski will feel vindicated. If it is confirmed, Falkowski will look sort of stupid.

But even if the resonance (or whatever it is) goes away, we can't be sure about it now. The only way to feel "sure" about it is to assume that no important new physics will ever be found. But if you really believe such a thing, you just shouldn't work in this portion of physics, Dr Falkowski, because by your assumption, your work is worthless.

It is absolutely healthy when the experimental deviations energize the research into some models. You know, a similar research into models takes place even in the absence of excesses. But by Bayes' theorem, the excesses increase the odds that certain models of new physics are right. You can calculate how big this increase is: it is a simple function of the formal $p$-value. If there is just a 0.01% formal probability that the cernette excess is a false positive, it is even justifiable to increase the activity on the models compatible with it by four orders of magnitude. In practice, a much smaller increase takes place. But some increase is undoubtedly justified.

Physicists often say that they're doing the research purely out of their curiosity and passion for the truth. In practice, it's almost never the case. People have personal ambitions and they also want jobs, salaries, grants, and maybe also fame. But that's true in other occupations, too. I don't think it's right to demonize the athletes among particle physicists. They're pretty amazing.

In particle physics, you can have counterparts of ATP and WTA rankings in tennis. Strumia is probably below veterans such as John Ellis. At the end, physics isn't just like tennis so the most important and famous physicists may be – and often are – non-athletes such as physics incarnations of monks. They're rather essential. But the physics athletes do a nontrivial part of the progress, anyway. Attempts to erase one of these whole groups amount to cultural revolutions of Mao's type. You just shouldn't think about such plans. Everyone who is dreaming about a similar cultural revolution surely misunderstands something important about the processes that make science – and the human society or the economy – work.

Whether or not the diphoton resonance is going to be confirmed, it was utterly reasonable and should be appreciated that some people did a lot of work on models that could explain such a deviation. At least, they worked on an exercise that had great chances to be relevant in Nature. But even if it weren't relevant, some of the lessons of this research may be applied in a world without the cernette, too. The experimental deviation has also been a natural source of the excitement and energy for the phenomenologists because many of them clearly do believe in their hearts that this excess could be real.

Incidentally, we may learn whether it's real very soon. In 2016, more than 5 inverse femtobarns have already been recorded by each major LHC detector. So before the end of June, 2016 has already beaten all of 2015. The data needed to decide about the fate of the theory that the cernette exists with the cross section indicated in 2015 have almost certainly been collected. Someone may already know the answer but it hasn't gotten out yet. It may change within days.

Bonus
An example of an activity much less justified than ambulance chasing, from Resonaances
Jason Stanidge said...

It doesn't look good IMO that none of the physicists listed come from leading institutions such as Harvard, Cambridge UK etc. Ah well: when the bump fades as will be soon rumoured by Jester, at least there is the possibility of other bumps in the data to look forward to.

Anonymous said...

Hi Jason Stanidge
are you runouring that the bump is fading away?
Now, this is an example of "trabant chasing with the hope that the trabant will turn into an ambulance". Anonymous has no rational reason to think that Jason Stanidge knows anything about the most recent LHC data. He is trying to push Jason to admit that he is an insider who knows something. And Jason has some probability to reply in a way that suggests that he may know something. But everyone has a nonzero probability to reply in this way. This "signal" would be artificially constructed by the "experimenter", Anonymous, which makes it much less tangible than the actual diphoton excess that was produced by the unique 2015 LHC dataset.

By the way, the comment about the leading institutions is illogical, too. The diphoton resonance has surely been worked on by numerous researchers from Harvard and all other top places, too. Moreover, I find it somewhat bizarre not to count Strumia's affiliation, CERN theory group, among the top places in particle physics. The winners of the ambulance chasing contests may be from other places than the Ivy League but that doesn't show that there's something "not good" about the intense work on currently intriguing experimental signs. You simply can't define the best character of work as whatever is being done at Harvard.