With the discovery of Higgs boson, two years ago, the media and a few scientists have presented the discovery as the final completion of the standard theory of particle physics, in such a way that we now know everything and do not need God. Hence the nickname given to Higgs boson, the God particle, a name, by the way, that Higgs does not like.
The discovery of a particle whose existence was predicted nearly a half century ago is a spectacular success of the standard theory, comparable to the success achieved in 1846 by Newton’s theory of universal gravitation with the discovery of Neptune, whose existence had been predicted by Le Verrier and Adams. Then it was also said that we now know everything.
|Urbain Le Verrier|
True, there was still a loose end, a very small discrepancy of just 43 seconds of arc per century in the precession of the orbit of Mercury. Le Verrier tried to repeat his success and predicted that this discrepancy was due to an unknown planet between Mercury and the Sun. He even gave it a name: Vulcan. For 60 years, many astronomers tried to find the mysterious planet in vain, for the problem in this case was in Newton’s theory, which eventually came to be just a first approximation of a new better theory that explained the discrepancy: Einstein's general relativity.
Could something similar happen to the standard theory of particle physics? Will its great success be followed by its first failure? Are there any loose ends still remaining in the theory?
The answer to the last question must be affirmative. The standard theory of particle physics has the following outstanding issues:
|Standard model of particle physics|
1. We don’t know why the two families of quarks have charges equal to -1/3 and 2/3, or why the two families of leptons have charges equal to -1 (electrons) and 0 (neutrinos).
2. The strong interaction has not been satisfactorily integrated with the electro-weak interaction.
3. The gravitational interaction is not covered by the model. Consequently, the standard theory of particle physics and Einstein's general relativity are incompatible.
4. This theory depends on 19 independent constants. Many physicists think they are too many.
5. It does not explain why the universe is made of matter, rather than antimatter.
6. It predicts that the energy of vacuum is infinite. To resolve this anomaly, physicists apply renormalization, which essentially consists of dividing by infinity, something that mathematics forbid.
7. The Higgs field does not explain why neutrinos have mass (as they seem to have, although very small).
8. If dark matter exists, as many cosmologists believe, it must be made of yet unknown particles not integrated in the model.
9. We do not know what the cosmologic dark energy may be.
10. Finally, it has not been proven that the standard theory of particle physics is consistent (i.e. it contains no contradictions).
In this situation, announcing that we already know everything seems an act of inconceivable arrogance (ὕβρις). The ancient Greeks knew very well where this usually ends.
Spanish version of this post
Thematic Thread on Particle Physics: Next