The Quest for Beauty
- Physics has so far discovered four fundamental forces. The gravitation
force (a simplification of Einstein's interaction between spacetime and mass)
makes "masses" move. Masses are made of atoms. Atoms are held together
by the electromagnetic force. The electromagnetic force binds electrons
and nuclei to form atoms (and it binds excess particles and antiparticles
to simply destroy each other).
The strong force attracts the constituents of atomic nuclei, that are built
out of quarks.
Thus the electromagnetic and strong forces basically create and maintain matter.
The weak force releases energy that would otherwise be trapped forever inside atoms. That energy eventually yields stars and living organisms.
- The formulas that describe the behavior of these forces are wildly different,
except for the gravitational and electromagnetic forces that are described by similar formulas (in a flat spacetime).
The distances at which they operate are also wildly different.
The strong force gets stronger at larger distances, while the others get
stronger at shorter distances.
- Each force is "mediated" by one or more "virtual" particles. Not surprisingly,
the type and number of virtual particles varies wildly from force to force.
Physics has so far discovered 60 particles:
the world is made of six leptons (the family of the electron) and 18 quarks,
with their antiparticles (a total of 48 "material" particles) plus
the photon for the electromagnetic force, three "bosons" for the weak force and eight gluons for the strong force (a total of 12 "virtual" particles).
- These elementary particles have masses that vary wildly. It turns out that the masses of these particles measure their interaction with an all-pervasive Higgs field.
- There is nothing that a sensible person would call "symmetry" in this picture
of the world.
Gravitation is quite anomalous, in that there should be a
virtual particle to mediate it (the "graviton") but nobody has found it. If
found, it would bring to 61 the number of elementary particles.
Physicists are also looking for the Higgs boson that bestows mass on particles.
If found, it would be particle number 62. And several more particles are needed to satisfy this or that theory.
- There are many arbitrary "constants" in Physics, from the speed of light to
the Planck constant to the gravitational constant to the mass of the electron; but everything pales
compared with the chaos of elementary particles.
- I believe that most of the chaos is due to the transition from an old
universe to the one in which we live. The "big bang" (or whatever started the
new universe) did not completely annihilate the previous universe. Remnants
of the old universe are still around. Physicists are trying to piece together
fragments that actually belong to different puzzles,
the same way that some genes in the human genome are remnants
from previous stages of evolution.
- Physicist look for a unified theory of all forces and puzzle why particles are all different. Biologists are more tolerant of diversity. Physics abhors evolution, otherwise it would simply accept that what we observe today is the result of the evolution of previous universes (each with its own laws of Nature, most of which did not disappear but merged with others).
Physics has been forced to accept the Big Bang but it fundamentally still
believes in the static and perfectly symmetric universe of the ancients.
- Perfection does not exist. Physicists are looking for a perfect
symmetry, for some beautiful array of forces and particles. However, this would
be in stark contrast with the Nature that we observe: no two rivers are alike,
no two lakes are alike, no two mountains are alike. Each has a shape that is
very hard to represent geometrically. The genome of any animal is hardly
an example of elegant mathematics, and its result (the body of an animal)
is hardly a perfect geometrical shape (especially the internal organs).
Nature is uglier than we make it to be.
What is "beautiful" for us is the fact that this Nature brought us to life.
But Nature itself has never displayed the mathematical beauty that scientists
are searching for.
- The human mind invented perfection, i.e. Mathematics and the sciences that
are based on it. However, the history of Science is largely an attempt by the
human mind to prove that Nature cannot be inferior to an artifact of the human
mind, that Nature beats the human mind at the game of imagining perfection.
- Humans will eventually have to accept that abstractions do not exist in
nature: we invented them, and they only live in our minds. The first large
geometric artifacts to appear in the universe were created by human minds
(whether furniture or buildings or vehicles).
- It is surprising that something as un-geometric as the human brain
is capable of perfectly geometrical abstractions. It is, however, a
mistake to assume that this is also what Nature does. Elementary particles and
elementary forces are an ugly mess for the simple fact that Nature mostly is
an ugly mess.
Beauty is not in the eye of the beholder but in the mind of the thinker.