Geology Reference
In-Depth Information
extraordinary fact—that 'positive' and 'negative' exist at all. What a mystery it is that
like charges repel, and unlike attract. The fact that these two polarities must always try to
be close to one another, to 'cancel' each other out, or to 'complement' each other— we
know not which—gives us all of biology and chemistry, and quite a lot of physics. The
French say that '
le contraire se touche
', and Aristotle said that two mysterious forces
run the universe—attraction and repulsion. He saw in this the action of
anima mundi
,
the ineluctable interiority that lies at the heart of matter-energy. We really can't do much
better than Aristotle when trying to get to the bottom of this, as it leads us nowhere to
reduce positive and negative charges to something more 'fundamental'; if one attempts
this kind of futile reductionism, one ends up with a highly unsatisfactory situation of in-
finite regress. Attraction and repulsion have something to do with the intelligence, with
the 'soul' of the universe itself—they are the manifestation at the level of matter/energy
of the participatory nature of electrons and protons, perhaps no different in principle to
the attractions and repulsions that we humans feel towards each other.
Thus, atoms, like humans, are constantly trying to find fulfilment. We find it in all
sorts of complex and various ways. For me, there is nothing better than walking out in a
wild, free, wildlife-rich, sun-soaked landscape, far from roads and the hubbub of modern
culture. For others, it might be standing for hours in a crowded stadium in the English
winter screaming encouragement to eleven men in shorts trying to kick a ball into a net
more frequently than an opposing gaggle of eleven men. For an atom, things seem to be
much simpler and more consistent—they
all
find fulfilment by arranging things so that
they have the right number of electrons orbiting their nucleus.
Bohr suggested that an atom's electrons are arranged in a set of concentric orbits.
The innermost orbit can hold a maximum of two electrons, the next one out, eight, the
one beyond that another eight, the next 18, then 32, and so on for the outer orbits which
needn't concern us here. Electrons in orbits closer to the nucleus have less energy than
those further out. The whole of chemistry, and the whole of life, depend on the simple
fact that every atom is utterly compelled to do whatever it can to end up with a full outer
orbit. Atoms aren't satisfied until they achieve this, and of course atoms can't do this
alone; they have to interact with each other to share or exchange outer electrons, and in
so doing they create the bewildering variety of
molecules,
or communities of atoms, that
we see in the worlds of chemistry, physics and biology. Each molecule is in an emergent
domain with properties not reducible to those of its constituent atoms. Water is a good
example. Two parts hydrogen and one part oxygen, its melting point, fluid dynamics,
expansion on freezing and so on cannot be fully predicted from a knowledge of oxygen
and hydrogen separately.
Gaia's Elements
