Peter Higgs |
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
Manuel Alfonseca
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