Geology Reference
In-Depth Information
which can take many complex forms but basically consist of a silicon-oxygen scaffold-
ing with many other atoms, including ionic calcium, held within it by the ubiquitous
forces of electrical attraction. The continents are made out of granite, and the sea floor
out of basalt, both of which, as we shall see later, are crucially important in regulating
Gaia's surface temperature.
The Origin of the Elements
We have now learnt a few basic things about the personalities of the major elemental be-
ings crucial to Gaia, but where did they come from? This question is relevant because,
by taking us into the realm of cosmology, it helps us to understand not only the origins of
our planet, but also to ponder its existence in relation to the universe as a self-organising,
evolving entity. One answer to the question is: 'out of the Big Bang'. In this mysterious
event, which happened some 15,000 million years ago, energy, matter, space and time
appeared out of nowhere in a primordial instant of creation. The startling thing about
this is that the universe didn't appear suddenly into a pre-existing space because space
was itself created along with the primordial energy, which we can still detect as the 'cos-
mic background radiation'. As the fireball spread it gradually cooled, until after the first
fifteen minutes the energy condensed into first electrons, and then, with further cooling,
into neutrons and protons. The nascent universe spread out as new space came into ex-
istence in between these newly formed elementary particles, and eventually, in the next
fifteen minutes, the cooling was sufficient to allow the coalescing of these particles into
hydrogen, the first elemental being born of the universe, and to this day the most abund-
ant of all the elements.
The Big Bang produced none of the heavier elements, other than some helium and
lithium, hydrogen's immediate neighbours in the periodic table. The heavier elements
were forged much later on, when atoms of hydrogen clumped together through gravit-
ational attraction to form the stars that coalesced as the universe cooled even further.
Eventually some of these clumps became so big that the pressures at their centres were
great enough to fuse hydrogen nuclei together into helium, releasing immense amount
of energy, some of it as visible light. In this way stars were born, and the whole uni-
verse lit up with their brilliance. The astonishing thing is that the conditions that lead to
the birth of stars are very finely balanced. If the gravitational attraction between bits of
matter had been just a little greater or smaller than it actually is, stars as we know them
would not have been possible, and without them the elements, the solar system and the
life our planet bears could not have existed.
