Chapter 9: The
fine-tuned Universe
A universe not made for us
In J D Salinger’s 1951 novel The
Catcher In The Rye, 16-year old Holden Caulfield asks a New York
cab driver “what happens to the fish when the lake freezes up?”. Cabbie doesn’t
know the answer of course, so he says “If
you was a fish, Mother Nature’d take care of you, wouldn’t she?”.
Actually, the entire lake doesn’t freeze. The top freezes, leaving
enough water (and oxygen) below for fish to survive the winter. Remember that
fish are “cold-blooded” — they don’t have to maintain a body temperature different from
their surroundings. This is one of the arguments in favour of a “fine-tuned”
universe — a world where
conditions are just right for the emergence of not just life but intelligent
life (us) and which could not be merely by chance.
What is wrong with this argument?
The argument starts from a moral value
(all life is precious and worth preserving) and uses it to explain an observed
fact (fish are able to survive the winter despite the freezing of the lake).
Most explanations of “how things work” that begin with a moral judgment of “how
things should be” end up providing a wrong explanation. A materialist
explanation for the same fact might go somewhat like this — the very fact that we find fish in a lake implies that
the lake could not completely freeze over. A lake that freezes completely,
would not have any fish. They would have died in the winter and you would not
be seeing them in the summer. So there is no need to assume that someone is looking
out for the fish… and for us by extension.
The fine-tuned Universe does actually find an echo in science, namely
the weak anthropic principle. There is no doubt
that a number of fairly strict conditions must prevail for our kind of
(carbon-based) life to exist; e.g. appropriate distance from the Sun,
approximately circular orbit, large neighbour planet (Jupiter) acting as a
“shield” and so on. But given a billion billion stars (with planets) it doesn’t
seem too much to assume this unlikely combination of favourable factors on at
least one planet
(ours). And given
that we are here, conditions had to be just right. Which is
different from saying that conditions were made just right so that we
(humans) could end up here — this being the “strong anthropic principle”.
Here’s a hypothetical conversation with an eight-year old -
Q: What are cows for?
A: To give us milk
Q: What are trees for?
A: To give us fruit to eat (or wood to make houses out of)
Q: What are rivers for?
A: To give us water (or to run boats on)
Now coming back to the question “what is the purpose of our existence?”
let’s ask instead “what is the purpose of a mosquito’s existence?”. From the
point of view of the mosquito, we already know the answer — the mosquito is a survival machine whose purpose is to
survive and multiply. But when asked from a human perspective the answer
doesn’t seem obvious at all. After all, if cows are “for” giving us milk,
mosquitoes must be “for” giving us malaria! The confusion arises because of
our anthropocentric
view of the world. It tries to draw a line on one side of
which lies the human species and on the other side, all other species. This
seems arrogant considering the claim of common descent of all species that we
made in Chapter 6.
The anthropocentric view may be a relatively recent one in the
evolution of the human species. It may have emerged after our survival as a
species became, or seemed to become, more or less guaranteed, barring
self-destruction. For most of human history (about one million years), the
survival of the human species was far from certain — several hominin (human-like) species became extinct before
we Homo Sapiens became a dominant species on the planet. But as humans who were
born recently (last 50,000 years), we may have found our environment to be
(miraculously) tailor-made for our existence. We may have found everything,
living and non-living, to show apparent signs of having been deliberately
“designed” and “created” for our benefit. Here’s another example, this time from a 15th
century Indian poet.
Now let’s see if we can do better than our eight-year old friend at
“biocentric” thinking (the opposite of anthropocentric)…
Q: Why are fruit round, fleshy and sweet?
Q: Why do we sneeze when we have a cold?
Q: How did dog come to be man’s best friend?
It’s time to dispel yet another misinterpretation of the theory of
evolution. Which is that evolution is some kind of progression from
“lower” to “higher” life-forms culminating in the human species. It most
certainly is not. The tree of
life does have a hierarchy based on common descent, with
more complex species (dolphins, chimpanzees, homo sapiens) entering the stage later.
It could be because more complex “designs” are less likely to evolve or less stable. They
would have come into existence after the more obvious ways of making a living
(ecological niches) were already “taken” by their simpler ancestors. There is
nothing to imply that more complex species were somehow the end goal of the
process of evolution.
Incidentally, the subtitle of this chapter refers to a video narrated
by Carl Sagan which explores this question from a cosmological angle. It leads
us to the same humbling conclusion — the fact that the Universe exists has nothing to do
with us.
We humans (and life in general) just happen to be a feature of it, albeit a
quite special feature. But science has by now dismantled the notion that we are
central to the Universe.
We seem to have established that shedding the anthropocentric position
is necessary in order to “think straight” within a Neo-Darwinist framework. But
how did we come to have an anthropocentric worldview?
Chapter 10: The
Intentional Stance
Don’t go looking for your Purpose in the Stars
There is no doubt that certain things do have a predefined purpose. These
things are all human-made objects. A car, phone and computer each have a
purpose which is the use for which it was designed and created by a human. But
all life-forms are evolved, not
designed. They are the result of the blind, purposeless process of evolution by
natural selection. The conclusion is this — the question of purpose (“what is it for”) is meaningful only for human-made artefacts and meaningless in
the context of Nature.
Dawkins, in his lecture series The
purpose of purpose, introduces the notion of archaeo-purpose
vs neo-purpose. The latter refers to adaptations (like the ability to set
“goals”) that originally evolved to further the cause of our survival but which
seem to have been subverted later. For example, an affinity for sugar and fat
would have been important for our survival at a time when calories, both ready
and stored, were precious. But because evolution happens over geological time,
our genes cannot adapt immediately to the surplus availability of calories. The
result? Coke and McDonald’s.
Let’s revisit the question we asked in Chapter 8 but deferred
answering. If our purpose as survival machines is “merely” to survive and
multiply, then why do we feel as
if we have some other, “higher” purpose? It could be that for an individual
whose survival is almost guaranteed (again, a fairly recent circumstance),
certain sub-goals branching out from the end goal of survival-reproduction have
been subverted and now appear to be end goals. How else would you persuade a
suicide bomber to blow themselves up? A similar line of reasoning can help
explain in evolutionary biological terms, pursuits like music (which birds also
engage in) and sports (which dogs sort of engage in). For a more general (and
more advanced) discussion on why there is a gap between how the world feels versus how
the world is,
see here and here.
The ability to spot patterns in data (visual or otherwise) has proved a
powerful adaptation contributing a great deal to our success as a species. For
example, our brains are hardwired to recognize faces. Even a crude :-) is
instantly interpreted as a smiling face. But are we also similarly hardwired to
find Reasons and Purposes everywhere, even when none exist? It may be something
we have evolved, and Dan Dennett calls it the Intentional Stance — attributing rationality, beliefs, desires and intentions
(in short attributing minds)
to agents (other humans, animals, machines, ourselves) to explain their
behaviour.
Andy Thomson calls this Hyperactive
Agency Detection. Even babies and animals are able to perceive
self-propelled movement differently from dependent movement, which demonstrates
an instinctive ability to detect agency. It’s easy to see how we came to be
programmed with this cognitive bias. Suppose you are walking in the grass and
hear a rustling sound. Now, it could be a snake or it could just be the wind.
If you mistake the wind for a snake you just laugh and keep walking (“false
positive”). But mistaking a snake for the wind could prove fatal (“false
negative”). Minimizing false negatives in this case is a “safe” strategy which
is coded into our instincts via natural selection. But taking an intentional
stance with respect to natural events produces superstition (and absurd notions
like the ones we encountered in Chapters 1 and 2) by attributing agency to
non-agents.
It can also lead to embarrassment. At a time when lightning was
attributed to the wrath of God, it was observed that in any town, the church
was more likely to be hit by lightning than any other
structure (including the brothel, gambling house and tavern…). Eventually science came to the rescue when Benjamin Franklin invented the
lightning rod in 1749.
Stepping outside the Darwinian world for a moment, here’s another idea
that runs contrary to our everyday experience — Newton’s law of inertia states that a body in uniform motion
will continue to be in uniform motion. It replaced Aristotle’s wrong notion
that the “natural state” of any body is to be at rest (never mind with respect
to what)
and that a force must be constantly applied to keep it in motion. Newton’s laws
of motion are today taken for granted, no questions asked. But this change in
thinking has a deeper significance, which is this — every change need not have a cause or driving
force.
Sean Carroll states this as follows — while the principle of cause and effect is a useful way
of thinking about things at a macro level (our everyday experience), physicists
don’t need to assume causes and effects to explain things at a fundamental
(i.e. particle) level. In other words, causality is an emergent macroscopic phenomenon.
It is related to the notion of entropy and
the arrow of time which we will not go over in detail
here. In fact, the 18th century philosopher David
Hume developed purely logical arguments against
causality without reference to particle physics (which wasn’t around at the
time).
Our minds, aided by language, also have another ability — “displaced reference”. This allows us to refer to an object or person that is
not present, in the third person. It could even be a dead person or a non-existent
“person” (say Spiderman). Andy Thomson calls this Decoupled Cognition — the ability to imagine minds that
are separate from bodies. This is useful for us to imagine situations that
involve other people, to predict what might happen and to formulate a strategy.
It seems to be a uniquely human trait. We are so used to this trick that you
may even be thinking “what’s wrong with that?”. Well, minds cannot exist
separate from bodies. Minds separate from bodies have many names — ghosts, spirits, soul etc. But just because we have the
ability to imagine them doesn’t mean they are real (recall Mind Projection
Fallacy from Chapter 2).
What about artificial intelligence (AI)? Can they not be considered
minds separate from bodies? This question will be addressed in Chapter 13.
Written by Ambar Nag.
ambarnag@gmail.com
(Continued in Part 5)
(Continued in Part 5)
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