Atheism and Theism JJ Haldane - Common Sense Atheism
Atheism and Theism JJ Haldane - Common Sense Atheism
Atheism and Theism JJ Haldane - Common Sense Atheism
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>Atheism</strong> <strong>and</strong> <strong>Theism</strong> 67<br />
which go as follows. An irregular bit of a larger molecular cloud broke off in<br />
such a way that it took a special form <strong>and</strong> was rotating about its centre. This<br />
irregularity allows an escape from the problem of the distribution of angular<br />
momentum between planets <strong>and</strong> the sun which beset La Place’s nebular<br />
hypothesis <strong>and</strong> its descendants. The dust grains accreted gravitationally into<br />
planetesimals <strong>and</strong> these into planets, the whole process involving collisions<br />
between the various bodies. Collisions indeed form an important part of the<br />
story, <strong>and</strong> account for many of the varying characteristics (such as differing<br />
inclinations to the ecliptic plane of the various planets). A large planet-sized<br />
object is supposed to have collided with the earth. The resulting splash of<br />
molten material formed the Moon, about 80 per cent of whose mass comes<br />
from material from the impacting body, so that the Moon’s constitution is<br />
dissimilar to that of the earth. The impacting body was destroyed in the<br />
collision <strong>and</strong> the collision stripped away the early atmosphere, which eventually<br />
was replaced (through gas emanating volcanically from the earth) by an<br />
atmosphere suitable for the evolution of life. This collision was a lucky accident<br />
for the prospect of life. Another lucky accident is that of the formation<br />
of the huge planet Jupiter in its position outside the asteroid belt, since it<br />
forms a gravitational barrier to comets. Without Jupiter perhaps a thous<strong>and</strong><br />
times as many would impact on the earth making conditions for life very<br />
difficult.<br />
The main matter of interest is how the formation of the solar system<br />
depended on a lot of accidents, <strong>and</strong> how uniformitarian theories of its origin<br />
are out of place. All the planets are importantly different from one another.<br />
So even if there are many such systems in the galaxy, few might be suitable<br />
for life <strong>and</strong> still fewer would develop intelligent life. Indeed Taylor is of the<br />
opinion that we are alone in the universe. 108 Remember that we need not only<br />
to multiply together all the probabilities of lucky astronomical accidents which<br />
led to our solar system containing a planet suitable for life, but we have to<br />
multiply this very small probability with the probabilities of all the lucky<br />
biological accidents in the biological evolutionary process. We then need to<br />
compare the reciprocal of this very small number with the huge number<br />
of stars like our sun in the galaxy, multiplied again by the huge number of<br />
galaxies. It is obviously very hard to estimate the probabilities <strong>and</strong> the final<br />
answer.<br />
Before I heard a lecture by Ross Taylor <strong>and</strong> read his book I was of the<br />
fairly conventional opinion put forward by astronomers that there are probably<br />
hundreds of millions of planets with planetary systems suitable for the<br />
evolution of life <strong>and</strong> that we are far from being the only intelligent beings in<br />
our galaxy, let alone in the universe, <strong>and</strong> that probably there are vast numbers<br />
of planets with intelligent beings technologically far in advance of ourselves.<br />
At any rate Ross Taylor’s considerations suggest that although planetary