Having complained at some length about how the Philosophia Naturalis blog carnival seemed to have died, I am pleased to report that another installment has arisen. Volunteers are needed to host the next edition (sign up before Christmas).
Before you a…

In simpler terms, the math behind Lisi’s theory doesn’t have enough room to hold all the particles we know about. There exist three “generations” of particles which make up the ordinary matter of the Universe (we don’t know what “dark matter” and “dark energy” are made of, just yet). Everything familiar — all the elements of the Periodic Table — are made of protons, neutrons and electrons, as we all learned in nursery school. Protons and neutrons are made of up and down quarks, but there are two other pairs of quarks: charm/strange and top/bottom. Quarks in these second and third “generations” have higher masses and are harder to find (you may recall the hullaballoo a while back about finally locating the top quark). The electron family also has its generations: the electron comes with an uncharged, very-low-mass partner called the electron neutrino, and two kinds of “heavy electron” also exist, called the muon and the tau, each one of which gets its own neutrino.

Why does Nature do everything three times over? Nobody knows. If you were in the Universe business, you could probably make a Cosmos full of stars and planets and life using only one generation, but we’ve got two extra. Maybe it’s a freak accident, or maybe it’s connected to some other aspect of natural law: perhaps we have three generations of particles because we live in three dimensions of space, or something like that. Speculations abound.

Any “theory of everything” (by which we mean a theory of all the basic building blocks) must incorporate this tripled structure of the fundamental particles. Lisi’s hypothesis doesn’t. You can pick one generation and incorporate it into your math, but you can’t get all three at the same time.

Sam