CERN produces marketing video for new collider and it’s full of lies

The Large Hadron Collider (LHC) just completed its second run. Besides a few anomalies, there’s nothing new in the data. After the discovery of the Higgs-boson, there is also no good reason for why there should be something else to find, neither at the LHC nor at higher energies, not up until 15 orders of magnitude higher than what we can reach now.

But of course there may be something, whether there’s a good reason or not. You never know before you look. And so, particle physicists are lobbying for the next larger collider.

Illustration of FCC tunnel. Screenshot from this video.

Proposals have been floating around for some while.

The Japanese, for example, like the idea of a linear collider of 20-30 miles length that would collide electrons and positrons, tentatively dubbed the International Linear Collider (ILC). The committee tasked with formulating the proposal seems to expect that the Japanese Ministry of Science and Technology will “take a pessimistic view of the project.”

Some years ago, the Chinese expressed interest in building a circular electron-positron collider (CEPC) of 50 miles circumference. Nima Arkani-Hamed was so supportive of this option that I heard it being nicknamed the Nimatron. The Chinese work in 5-year plans, but CEPC evidently did not make it on the 2016 plan.

CERN meanwhile has its own plan, which is a machine called the Future Circular Collider (FCC). Three different variants are presently under discussion, depending on whether the collisions are between hadrons (FCC-hh), electron-positions (FCC-ee), or a mixture of both (FCC-he). The plan for the FCC-hh is now subject of a study carried out in a €4 million EU-project.

This project comes with a promotional video:



The video advertises the FCC as “the world’s biggest scientific instrument” that will address the following questions:

What is 96% of the universe made of?

This presumably refers to the 96% that are dark matter and dark energy combined. While it is conceivably possible that dark matter is made of heavy particles that the FCC can produce, this is not the case for dark energy. Particle colliders don’t probe dark energy. Dark energy is a low-energy, long-distance phenomenon, the entire opposite from high-energy physics. What the FCC will reliably probe are the other 4%, the same 4% that we have probed for the past 50 years.

What is dark matter?

We have done dozens of experiments that search for dark matter particles, and none has seen anything. It is not impossible that we get lucky and the FCC will produce a particle that fits the bill, but there is no knowing it will be the case.

Why is there no more antimatter?

Because if there was, you wouldn’t be here to ask the question. Presumably this item refers to the baryon asymmetry. This is a fine-tuning problem which simply may not have an answer. And even if it has, the FCC may not answer it.

How did the universe begin?

The FCC would not tell us how the universe began. Collisions of large ions produce little blobs of quark gluon plasma, and this plasma almost certainly was also present in the early universe. But what the FCC can produce has a density some 70 orders of magnitude below the density at the beginning of the universe. And even that blob of plasma finds itself in a very different situation at the FCC than it would encounter in the early universe, because in a collider it expands into empty space, whereas in the early universe the plasma filled the whole universe while space expanded.

On the accompanying website, I further learned that the FCC “is a bold leap into completely uncharted territory that would probe… the puzzling masses of neutrinos.”

The neutrino-masses are a problem in the Standard Model because either you need right-handed neutrinos which have never been seen, or because the neutrinos are different from the other fermions, by being “Majorana-particles” (I explained this here).

In the latter case, you’re not going to find out with a particle collider; there are other experiments for that (quick summary here). In the former case, the simplest model has the masses of the right-handed neutrinos at the Planck scale, so the FCC would never see them. You can of course formulate models in which the masses are at lower energies and happen to fall into the FCC range. I am sure you can. That particle physicists can fumble together models that predict all and everything is why I no longer trust their predictions. Again, it’s not impossible the FCC would find something, but there is no good reason for why that should happen.

I am not opposed to building a larger collider. Particle colliders that reach higher energies than we probed before are the cleanest and most reliable way to search for new physics. But I am strongly opposed to misleading the public about the prospects of such costly experiments. We presently have no reliable prediction for new physics at any energy below the Planck energy. A next larger collider may find nothing new. That may be depressing, but it’s true.

Correction: The video in question was produced by the FCC study group at CERN and is hosted on the CERN website, but was not produced by CERN.