Thursday, January 8, 2015

Anthropic and supranthropic properties

In a previous post I wrote about the fine tuning problem, based on the verification that many of the properties of the universe seem designed to make our existence possible. In other words: those properties verify the anthropic principle, another way of saying that the universe must fulfill all the conditions needed for our existence, since we are here. On the other hand, the mediocrity principle states that the anthropic conditions of the universe should be the necessary minimum to make our existence possible.
Robin James Spivey has lately published a book titled Aqueous solution, where he asserts that certain properties of the cosmos are supranthropic (they go beyond the anthropic principle) because they are not required for our existence, but their presence guarantees our long-range survival. According to Spivey, those properties are an inkling of design stronger than the anthropic properties, as the mediocrity principle opposes their presence.

Let us consider as an example the anthropic properties of iron and nickel. Two isotopes of these elements, 62Ni and 56Fe, have the highest possible nuclear binding energy. In the reactions taking place in certain stars, 56Ni is the heaviest element that can be built by means of fusion, but being radioactive, it decays spontaneously into 56Fe, the most stable isotope of them all. When those stars become supernovae (they explode) most of the matter they spread in space is made of iron and nickel with a spattering of silicates. It so happens that iron and nickel (with cobalt) are the only ferromagnetic elements. Their ferromagnetism helps keeping lumps of matter together, that finally become Earth-like planets. As the two metals are denser, iron and nickel end-up in the core of the planet, while the lighter silicates build the mantle and the crust. If the planet spins with enough speed, their ferromagnetic core generates a magnetic field that deflects the noxious particles of the solar wind that would sweep along the planet atmosphere and destroy the budging life. Therefore, without the peculiar properties of iron and nickel and the fact that a mixture of those two elements is most abundant in supernovae explosions, perhaps life would not be possible.
Let us look now at the supranthropic properties of iron, according to Spivey. It so happens that iron, at pressure and temperature conditions similar to those in the core of Earth-like planets, can be in two different phases: hcp and fcc. Just before the transition between those two phases, the energy of orbital 3d in the iron atom (usually empty) gets lower, until it becomes less than the energy of the 4s orbital (which usually contains one electron). Just before the intersection of both energies, in a zone corresponding to the pressure and temperature at the core of Earth-like planets, the transition energy between both orbitals could be equal to the disintegration energy of a neutrino and its corresponding anti-neutrino. The core of a planet could therefore absorb that energy. If the number of neutrinos were sufficient, that energy would be enough to assure the persistence of life in that planet, even in the absence of a nearby star. Therefore, the supranthropic properties of iron could assure our long-lasting existence beyond the end of stars in the universe.
Can this theory be tested? Spivey proposes several ways. On the one hand, the neutrino and the anti-neutrino should be the same particle, which has been proposed but not proved. On the other hand, to optimize the indicated effect, the mass of the neutrino should be about 0.05 electron-Volt (we just know that it must be lower than 2 eV). Finally Spivey launches the hypothesis of the existence of a new particle (a sterile neutrino with a mass around 1.5 eV) which should be the main component of dark matter and would help keep together all the ordinary neutrinos in galaxies. All these predictions should be testable (or falsifiable) in a not too far future.
Spivey then offers an original solution to the Fermi paradox (if there are any extra-terrestrial intelligences, why aren’t they here?). He says that the Milky Way has not enough neutrinos to assure our long-range existence. To find them, we should travel to the nearest galactic cumulus, Virgo, 60 million light-years from us. Spivey’s answer to the paradox is this: they are not here because they have all migrated to Virgo cumulus, as we will do when our scientific progress will make it possible to test this theory, and our technological progress will make it possible to travel to another galaxy.

Is this science-fiction? Just now, it is, just the same as the multiverse theories presented by many physicists as serious science. This one, at least, can be falsified.

Manuel Alfonseca

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