Authors: Unknown
The
truly adult view, by contrast, is that our life is as meaningful, as
full and as wonderful as we choose to make it. And we can make it very
wonderful indeed. If science gives consolation of a non-material kind,
it merges into my final topic, inspiration.
This
is a matter of taste or private judgement, which has the slightly
unfortunate effect that the method of argument I must employ is
rhetoric
rather than logic. I've done it before, and so have many others
including, to name only recent examples, Carl Sagan in
Pale
Blue Dot,
E. O. Wilson in
Biophilia,
Michael
Shermer in
The Soul of Science
and Paul Kurtz in
Affirmations.
In
Unweaving the Rainbow
I tried to
convey how lucky we are to be alive, given that the vast majority of
people who could potentially be thrown up by the combinatorial lottery
of DNA will in fact never be born. For those of us lucky enough to be
here, I pictured the relative brevity of life by imagining a laser-thin
spotlight creeping along a gigantic ruler of time. Everything before or
after the spotlight is shrouded in the darkness of the dead past, or
the darkness of the unknown future. We are staggeringly lucky to find
ourselves in the spotlight. However brief our time in the sun, if we
waste a second of it, or complain that it is dull or barren or (like a
child) boring, couldn't this be seen as a callous insult to those
unborn trillions who will never even be offered life in the first
place? As many atheists have said better than me, the knowledge that we
have only one life should make it all the more precious. The atheist
view is correspondingly life-affirming and life-enhancing, while at the
same time never being tainted with self-delusion, wishful thinking, or
the whingeing self-pity of those who feel that life owes them
something. Emily Dickinson said,
That
it will never come again
Is what makes life so sweet.
If
the demise of God will leave a gap, different people will fill it in
different ways. My way includes a good dose of science, the honest and
systematic endeavour to find out the truth about the real world. I see
the human effort to understand the universe as a model-building
enterprise. Each of us builds, inside our head, a model of the world in
which we find ourselves. The minimal model of the world is the model
our ancestors needed in order to survive in it. The simulation software
was constructed and debugged by natural selection, and it is most adept
in the world familiar to our ancestors on the African savannah: a
three-dimensional world of medium-sized material objects, moving at
medium speeds relative to one another. As an unexpected bonus, our
brains turn out to be powerful
enough to accommodate a much richer world model than the mediocre
utilitarian one that our ancestors needed in order to survive. Art and
science are runaway manifestations of this bonus. Let me paint one
final picture, to convey the power of science to open the mind and
satisfy the psyche.
One
of the unhappiest spectacles to be seen on our streets today is the
image of a woman swathed in shapeless black from head to toe, peering
out at the world through a tiny slit. The burka is not just an
instrument of oppression of women and claustral repression of their
liberty and their beauty; not just a token of egregious male cruelty
and tragically cowed female submission. I want to use the narrow slit
in the veil as a symbol of something else.
Our
eyes see the world through a narrow slit in the electromagnetic
spectrum. Visible light is a chink of brightness in the vast dark
spectrum, from radio waves at the long end to gamma rays at the short
end. Quite
how
narrow is hard to appreciate and a
challenge to convey. Imagine a gigantic black burka, with a vision slit
of approximately the standard width, say about one inch. If the length
of black cloth above the slit represents the short-wave end of the
invisible spectrum, and if the length of black cloth below the slit
represents the long-wave portion of the invisible spectrum, how long
would the burka have to be in order to accommodate a one-inch slit to
the same scale? It is hard to represent it sensibly without invoking
logarithmic scales, so huge are the lengths we are dealing with. The
last chapter of a book like this is no place to start tossing
logarithms around, but you can take it from me that it would be the
mother of all burkas. The one-inch window of visible light is
derisorily tiny compared with the miles and miles of black cloth
representing the invisible part of the spectrum, from radio waves at
the hem of the skirt to gamma rays at the top of the head. What science
does for us is widen the window. It opens up so wide that the
imprisoning black garment drops away almost completely, exposing our
senses to airy and exhilarating freedom.
Optical
telescopes use glass lenses and mirrors to scan the heavens, and what
they see is stars that happen to be radiating in the narrow band of
wavelengths that we call visible light. But other telescopes 'see' in
the X-ray or radio wavelengths, and present to us a cornucopia of
alternative night skies. On a smaller scale, cameras with appropriate
filters can 'see' in the ultraviolet and take photographs of flowers
that show an alien range of stripes and spots that are visible to, and
seemingly 'designed' for, insect eyes but which our unaided eyes can't
see at all. Insect eyes have a spectral window of similar width to
ours, but slightly shifted up the burka: they are blind to red and they
see further into the ultraviolet than we do -into the 'ultraviolet
garden'.*
*
'The Ultraviolet Garden' was the title of one of my five Royal
Institution Christmas Lectures, originally televised by the BBC under
the general title 'Growing Up in the Universe'. The whole series of
five lectures will be made available at www.richarddawlcins.net, the
website of the Richard Dawkins Foundation.
The
metaphor of the narrow window of light, broadening out into a
spectacularly wide spectrum, serves us in other areas of science. We
live near the centre of a cavernous museum of magnitudes, viewing the
world with sense organs and nervous systems that are equipped to
perceive and understand only a small middle range of sizes, moving at a
middle range of speeds. We are at home with objects ranging in size
from a few kilometres (the view from a mountaintop) to about a tenth of
a millimetre (the point of a pin). Outside this range even our
imagination is handicapped, and we need the help of instruments and of
mathematics - which, fortunately, we can learn to deploy. The range of
sizes, distances or speeds with which our imaginations are comfortable
is a tiny band, set in the midst of a gigantic range of the possible,
from the scale of quantum strangeness at the smaller end to the scale
of Einsteinian cosmology at the larger.
Our
imaginations are forlornly under-equipped to cope with distances
outside the narrow middle range of the ancestrally familiar. We try to
visualize an electron as a tiny ball, in orbit around a larger cluster
of balls representing protons and neutrons. That isn't what it is like
at all. Electrons are not like little balls. They are not like anything
we recognize. It isn't clear that 'like' even means anything when we
try to fly too close to reality's further horizons. Our imaginations
are not yet tooled-up to penetrate the neighbourhood of the quantum.
Nothing at that scale behaves in the
way matter - as we are evolved to think - ought to behave. Nor can we
cope with the behaviour of objects that move at some appreciable
fraction of the speed of light. Common sense lets us down, because
common sense evolved in a world where nothing moves very fast, and
nothing is very small or very large.
At
the end of a famous essay on 'Possible Worlds', the great biologist J.
B. S. Haldane wrote, 'Now, my own suspicion is that the universe is not
only queerer than we suppose, but queerer than we can suppose ... I
suspect that there are more things in heaven and earth than are dreamed
of, or can be dreamed of, in any philosophy.' By the way, I am
intrigued by the suggestion that the famous Hamlet speech invoked by
Haldane is conventionally misspoken. The normal stress is on 'your':
There
are more things in heaven and earth, Horatio,
Than are dreamt of in
your
philosophy.
Indeed,
the line is often plonkingly quoted with the implication that Horatio
stands for shallow rationalists and sceptics everywhere. But some
scholars place the stress on 'philosophy', with 'your' almost
vanishing: '. . . than are dreamt of inya
philosophy.'
The
difference doesn't really matter for present purposes, except that the
second interpretation already takes care of Haldane's 'any' philosophy.
The
dedicatee of this book made a living from the strangeness of science,
pushing it to the point of comedy. The following is taken from the same
extempore speech in Cambridge in 1998 from which I have already quoted:
'The fact that we live at the bottom of a deep gravity well, on the
surface of a gas-covered planet going around a nuclear fireball ninety
million miles away and think this to be
normal
is
obviously some indication of how skewed our perspective tends to be.'
Where other science-fiction writers played on the odd-ness of science
to arouse our sense of the mysterious, Douglas Adams used it to make us
laugh (those who have read
The Hitchhiker's Guide to the
Galaxy
might think of the 'infinite improbability drive',
for instance). Laughter is arguably the best response to some of the
stranger paradoxes of modern physics. The alternative, I sometimes
think, is to cry.
Quantum
mechanics, that rarefied pinnacle of twentieth-century scientific
achievement, makes brilliantly successful predictions about the real
world. Richard Feynman compared its precision to predicting a distance
as great as the width of North America to an accuracy of one human
hair's breadth. This predictive success seems to mean that quantum
theory has got to be true in some sense; as true as anything we know,
even including the most down-to-earth common-sense facts. Yet the
assumptions
that quantum theory needs to make, in order to deliver those
predictions, are so mysterious that even the great Feynman himself was
moved to remark (there are various versions of this quotation, of which
the following seems to me the neatest): 'If you think you understand
quantum theory . . . you don't understand quantum theory.'*
* A
similar remark is attributed to Niels Bohr: 'Anyone who is not shocked
by quantum theory has not understood it.'
Quantum
theory is so queer that physicists resort to one or another paradoxical
'interpretation' of it. Resort is the right word. David Deutsch, in
The
Fabric of Reality,
embraces the 'many worlds' interpretation
of quantum theory, perhaps because the worst that you can say of it is
that it is preposterously
wasteful.
It postulates
a vast and rapidly growing number of universes, existing in parallel
and mutually undetectable except through the narrow porthole of
quantum-mechanical experiments. In some of these universes I am already
dead. In a small minority of them, you have a green moustache. And so
on.
The
alternative 'Copenhagen interpretation' is equally preposterous - not
wasteful, just shatteringly paradoxical. Erwin Schrodinger satirized it
with his parable of the cat. Schrodinger's cat is shut up in a box with
a killing mechanism triggered by a quantum-mechanical event. Before we
open the lid of the box, we don't know whether the cat is dead. Common
sense tells us that, nevertheless, the cat must be either alive or dead
inside the box. The Copenhagen interpretation contradicts common sense:
all that exists before we open the box is a probability. As soon as we
open the box, the wave function collapses and we are left with the
single event: the cat is dead, or the cat is alive. Until we opened the
box, it was neither dead nor alive.
The
'many worlds' interpretation of the same events is that in some
universes the cat is dead; in other universes the cat is alive. Neither
interpretation satisfies human common sense or intuition. The more
macho physicists don't care. What matters is that the mathematics
work, and the predictions are experimentally fulfilled. Most of us are
too wimpish to follow them. We seem to
need
some
sort of visualization of what is 'really' going on. I understand, by
the way, that Schrodinger originally proposed his cat
thought-experiment in order to expose what he saw as the absurdity of
the Copenhagen interpretation.
The
biologist Lewis Wolpert believes that the queerness of modern physics
is just the tip of the iceberg. Science in general, as opposed to
technology, does violence to common sense.
156
Here's a favourite example: every time you drink a glass of water, the
odds are good that you will imbibe at least one molecule that passed
through the bladder of Oliver Cromwell. It's just elementary
probability theory. The number of molecules per glassful is hugely
greater than the number of glassfuls in the world. So every time we
have a full glass, we are looking at a rather high proportion of the
molecules of water that exist in the world. There is, of course,
nothing special about Cromwell, or bladders. Haven't you just breathed
in a nitrogen atom that was once breathed out by the third iguanodon to
the left of the tall cycad tree? Aren't you glad to be alive in a world
where not only is such a conjecture possible but you are privileged to
understand why? And publicly explain it to somebody else, not as your
opinion or belief but as something that they, when they have understood
your reasoning, will feel compelled to accept? Maybe this is an aspect
of what Carl Sagan meant when he explained his motive in writing
The
Demon-Haunted World: Science as a Candle in the Dark: 'Not
explaining
science seems to me perverse. When you're in love, you want to tell the
world. This book is a personal statement, reflecting my lifelong love
affair with science.'