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Symptoms of the Crisis

First of all, yes, there is a crisis. The standard model is decades old and no significant deeper understanding of nature at the fundamental level has been achieved.

Even worse, most students and many researchers work on projects they don' t believe in. For too many people, physics has become “just another job”.

The Current Situation According to H. Georgi

“The progress of the field is determined, in the long run, by the progress of experimental particle physics. Theorists are, after all, parasites. Without our experimental friends to do the real work, we might as well be mathematicians or philosophers.

When the science is healthy, theoretical and experimental particle physics track along together, each reinforcing the other. These are the exciting times. But there are often short periods during which one or the other aspect of the field gets way ahead. Then theorists tend to lose contact with reality. This can happen either because there are no really surprising or convincing experimental results being produced (in which case I would say that theory is ahead – this was the situation in the late 1970s and early 1980, before the discovery of the W and Z) or because the experimental results, while convincing, are completely mysterious (in which case I would say that experiment is ahead – this was the situation during much of the 1960s).

During such periods, without experiment to excite them, theorists tend to relax back into their ground states, each doing, whatever comes most naturally. As a result, since different theorists have different skills, the field tends to fragment into little subfields. Finally, when the crucial ideas or the crucial experiments come along and the field regains its vitality, most theorists find that they have been doing irrelevant things.

But the wonderful thing about physics is that good theorists don’t keep doing irrelevant things after experiment has spoken. The useless subfields are pruned away and everyone does more or less the same thing for a while, until the next boring period. […]

As I suggested at the beginning of this chapter, I am somewhat concerned about the present state of particle theory. The problem is, as I mentioned before, that we are in a period during which experiment is not pushing us in any particular direction. As such times, particle physicists must be especially careful.

We now understand the strong, weak and electromagnetic interactions pretty well. Of course, that doesn’t mean that there isn’t anything left to do in these fields any more than the fact that we understand quantum electrodynamics means that there is nothing left to do in atomic physics. The strong interactions, quantum chromodynamics, in particular will rightly continue to absorb the energies of lots of theorists for many decades to come. But it is no longer frontier particle physics in the sense that it was fifteen years ago.”Howard Georgi in “Effective quantum field theories”, which was published in the book “The New Physics” edited by P. Davies (1989)

In a similar spirit are the “two laws” of T. D. Lee:

1. Without experimentalists, theorists tend to drift. 2. Without theorists, experimentalists tend to falter.

Is there a crisis?

There can be no doubt that after almost a century of impressive success fundamental physics is in the midst of a deep crisis. Its epicenter is located in particle theory, but its repercussions may influence the direction of experimental particle physics and affect adjacent areas of fundamental research.

String theory and the crisis in particle physics by Bert Schroer

Theoretical physics is at a crossroads right now…In a sense we’ve entered a very deep crisis. Neil Turok

There are many indications that, following the recursive pattern of scientific revolutions, we are now witnessing the beginning of the phase of crisis. The lack of new physics in the initial stages of the LHC project is putting into question the logic of naturalness when applied to the Higgs; the absence of a positive detection in dark matter experiments is casting doubts about nature taking advantage of the WIMP miracle. We are not simply confronted with experimental data excluding a model or a class of models. We are confronted with the need to reconsider the guiding principles that have been used for decades to address the most fundamental questions about the physical world. These are symptoms of a phase of crisis.


There is a widespread sensation that the organising principles based on symmetry and separation of scales, which follow from an effective quantum field theory approach, in spite of their triumphs, must be superseded by new organising principles. Physicists are in search for new conceptual paradigms, which is another symptom of a phase of crisis.

The Dawn of the Post-Naturalness Era by Gian Francesco Giudice

It is always worth remembering why we do physics. While we can make a long list of how society benefits from physics research in general, the

“primary goal of fundamental physics is to discover profound concepts that illuminate our understanding of nature.” F. Wilczek

In physics we want to find out what makes nature tick at the most fundamental level. How much progress have we made in the last, say, 40 years towards this goal? Well, on the experimental side there was the discovery of the Higgs boson… Anything else? How many profound theoretical discoveries have been made?

While there certainly were some ideas, they all turned out to be wrong. As mentioned above, we do not want to dive into the details here, because there are already good books that critically discuss the theoretical ideas of the last decades.

There have never been so many physicists as today. Thousands of people around the globe spent all their time “doing physics”. Still there is little to no progress. This paradox is nicely summarized by the following famous joke:

“The Physical Review is now so voluminous that stacking up successive issues would generate a surface traveling faster than the speed of light - although without violating relativity because the Physical Review contains no information.” R. B. Laughlin

You don't need to take our word for it. Most physicist have noticed that something is wrong.

For example, Steven Weinberg recently remarked that he has noticed “that the smart guys such as Witten seem to have turned their attention to solid-state physics lately” and “maybe ”that’s a sign that they are giving up“.

In a similar spirit, Nima Arkani-Hamed remarked after presenting ”the only picture of the world that I know where everything that we learned experimentally and theoretically for the last 30 years has some role to play in it“ that ”my confidence in it is not so super high, and I definitely think its worth thinking about completely radically different things.

How can this be? Maybe we simply have already discovered everything? Maybe discoveries nowadays are particularly hard?

Firstly, no! We certainly have not discovered everything. There are hundreds of open questions and unsolved puzzles. No one actually believes that our current theory is the end of the story.

Secondly, discoveries are always hard. To quote Nelson Mandela: “It always seems impossible until it’s done.

Here we discuss different reasons for the current crisis in physics. The problem is complex and there is certainly no simple solution. The deep roots of the current crisis lie in how physics is taught and in how the physics research community works nowadays.

“We are drowning in information and starving for knowledge.”

Rutherford D. Roger

Further Reading

symptoms.txt · Last modified: 2018/02/25 09:21 by jakobadmin