To start the new decade there’s an article very much worth reading by Misha Shifman, entitled Musings on the Current State of HEP. It’s somewhat of an update of something he wrote back in 2012, which I wrote about here. He starts off with:
Now, seven years later, I will risk to offer my musings on the same subject.The seven years that have elapsed since [1] brought new perspectives: the tendencies which were rather foggy at that time became pronounced. My humble musings do not pretend to be more than they are: just a personal opinion of a theoretical physicist… For obvious reasons I will focus mostly on HEP, making a few marginal remarks on related areas. I would say that the most important message we have received is the absence of dramatic or surprising new results. In HEP no significant experimental findings were reported, old ideas concerning Beyond the Standard Model (BSM) physics hit dead-ends one after another and were not replaced by novel ideas. Hopes for key discoveries at the LHC (such as superpartners) which I mentioned in 2012 are fading away. Some may even say that these hopes are already dead. Low energy supersymmetry is ruled out, and gone with it is the concept of naturalness, a basic principle which theorists cherished and followed for decades. Nothing has replaced it so far…
HEP, “my” branch of theoretical physics since the beginning of my career, seems to be shrinking. A change of priorities in HEP in the near future is likely as business as usual is not sustainable. The current time is formative.
I encourage you to take a look at the rest, there’s a lot more detailed discussion of the state of HEP and allied fields, especially about the central role of quantum field theory.
Shifman also includes a section very critical of Richard Dawid, the “non-empirical confirmation” business and talks given at the “Why Trust a Theory?” conference (discussed here):
With all due respect I strongly disagree with Richard Dawid and all supporting speakers at the conference and beyond… I object against applying the term “non-empirically confirmed” to science (the more so, the term “postempiric science”). Of course, we live in liberal times and everybody is entitled to study and discuss whatever he or she wants. But the word science is already taken. Sorry, colleagues. For “postempiric science,” please, use another word, for instance, iScience, xScience, or something else.
As for David Gross’s attempt to claim that string theory is, like quantum mechanics and quantum field theory, not testable just because it is a framework, not a theory, Shifman is having none of it:
David Gross is a great theoretical physicist, whose discovery of asymptotic freedom made him immortal, but I respectfully disagree with him. Framework or not, both QM and QFT have absolutely solid confirmations in all their aspects in thousands of experiments.
As for the once popular idea that string theory could provide a “theory of everything”, he writes:
Well… it never happened and – I will risk to say – never will.
Hi Peter,
happy new year to you and your readers.
At last, at last one well known theoretical physicist comes out openly and says loud and clear what many already think, but are afraid of saying or writing due to repercussions in their professional lives.
Yes, string theory is NOT the so much sought after “theory of everything”. Susskind has already said it half a dozen times. Arkani-Hamed has semi-implied it. I wonder, and have written on this blog post before, when will all the big guns come out and acknowledge it publicly.
I guess money and egos are running high there…
Your web site http://www.math.columbia.edu/~woit/wordpress/ gives a warning which you may want to to eliminate. Using Firefox, Chrome or MS Edge the padlock icon may have a red line through it. It’s a security notice which may scare off people from going to your site.
Jack
Jack Harvey (and anyone interested in why the browsers are giving warnings),
What’s happening is that while the main connection to the blog is SSL encrypted (https), there are lots of scripts and code in WordPress and the plugins being used that use http, not https. Eliminating all of these occurrences would be a lot of effort and not actually solve any significant security problem, so not a high priority right now.
sort of OT: The Economist surveys collider proposals in “Assembling the future” in its 4 Jan edition.
In fig. 1 Shifman plots particle physics as a dead trunk. Other authors one day earlier wrote that we must “communicate much more convincingly the prospective economical, societal, environmental and cultural impacts of HEP” (arxiv.org/pdf/1912.13466.pdf). Who is right?
Art,
Thanks. For others, that story is at
https://www.economist.com/science-and-technology/2020/01/02/finding-new-physics-will-require-a-new-particle-collider
Mostly well-done, but gets a few things wrong:
1. The problem with electron beams is not that less mass means less kinetic energy, but less mass means the synchrotron radiation problem described later is much worse.
2. Introducing superpartners doesn’t reduce the number of free parameters of the Standard Model, quite the opposite: it adds many more.
I hadn’t heard of opposition by the US to a Chinese collider since US scientists wouldn’t be allowed to work on it. As far as I can tell, a US physicist (Arkani-Hamed) is still director of the Chinese institute planning such a machine, see
http://cfhep.ihep.ac.cn/
Alessandro Strumia,
Thanks. The Shifman article is about HEP theory, and there’s a good argument that it has now been dead for a while. The other article you link to is about the experimental HEP side, and provides a good update and summary of the problem of a next generation European collider. There the problem I think is not that energy frontier experimental HEP is dead, but that it has a serious medical issue: major organ failure projected for 2035 or so, and a replacement organ will be extremely expensive, unclear how to pay for it. Close family members are saying “not worth keeping it alive, it’s a goner anyway, so why should we go into hock to save it, money will be better spent on something else”. Thus the line you quote.
The article gives a good summary of the problem:
“major changes will be needed with respect to the present CERN way of programme realisation: exceptional and quite substantial contributions from the host states, significant contributions from non-member states participating in this programme and preferential loans with long-term reimbursement profiles. We assume that this should be possible.”
Depicting Post Empirical Science as a tiny toxic mushroom next to a great tree of Physics is very accurate. In my view a polypore on a tree would represent the situation slightly more faithfully.
Speaking of CERN funding, did we ever find out which nations didn’t pony up the €100 million and why?
Ironically enough, just a few hours after this post, Icecube ruled out the last Standard Model explanation of ANITA’s anomalous neutrino events:
https://icecube.wisc.edu/news/view/709
Parravicini 2036,
Unfortunately I don’t think ANITA seeing just two hard to understand signals and ICECUBE seeing nothing adds up to bringing down the Standard Model. About ANITA, Sabine Hossenfelder had some comments here
https://backreaction.blogspot.com/2019/07/science-shrugs.html
The usual “extraordinary claims require extraordinary evidence” principle applies.
Hi Peter,
I just read this article regarding the DoE’s approval (this past Thursday) of Brookhaven’s proposed Electron-Ion Collider (EIC), and thought that I would share:
https://www.energy.gov/articles/us-department-energy-selects-brookhaven-national-laboratory-host-major-new-nuclear-physics
Also at Science magazine here:
https://www.sciencemag.org/news/2020/01/department-energy-picks-new-york-over-virginia-site-new-particle-collider
Nick M.,
Thanks. I note that the Science article explains something that is not known to most people:
“The decision on a machine still 10 years away reflects the relative good times for DOE science funding, Dabbar says. “We’ve been able to start on every major project that’s been on the books for years.” DOE’s science budget is up 31% since 2016—in spite of the fact that under President Donald Trump, the White House has tried to slash it every year.”
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