One of the more startling findings in astrophysics in recent
years is the discovery that there isn’t nearly enough matter in the visible universe
to account for the gravitational pull that holds the spinning galaxies
together. Given the amount of matter we
can detect, galaxies spinning at the rate we see should fly apart under centrifugal
force. In fact, current theory estimates
that all the matter we see comprises only about 4% of the universe, the other
96% being made up of what is tentatively named “dark matter” and “dark energy”.
I propose that the same is roughly true of our current state
of knowledge. That despite all the wonderful discoveries in physics and
chemistry and biology over the past few hundred years, we are still just barely
scratching the surface. That we know something
like 4% of what is to be known, and even that may be wildly optimistic.
Case in point: we can accurately describe gravity. Given masses and distances we can predict the resulting gravitational forces with enough accuracy to send
spacecraft safely throughout the cosmos.
Yet in fact we still have not the faintest idea why two masses ought to
attract each other. Oh, physicists have fancy equations, and theoretical
constructs like “gravitons” and “space-time distortions”, but at root we are still clueless about how
gravity really works.
Case in point: like gravity, we can accurately describe
magnetism, create magnets with metals or electric fields , use magnetism for
things like motors, but also like gravity we still have no idea at all why
electric fields or certain metals create these fields, or why these fields
produce attractive/repellent forces, but only on some elements and not on
others.
These two examples mimic human use of fire. We humans and our pre-human ancestors have
apparently made use of fire for up to a million years, but only since the
development of chemistry in the past couple of hundred years have we had the
faintest idea what was really going on in a fire.
In the field of biology things are even worse. We understand
more or less the physical structure of the brain and of neurons, but are a long way from having the faintest
idea how these operate to create “thoughts’ or “self-awareness”. We can see how blood vessels operate, but have
hardly a clue how a developing fetus makes a blood vessel grow from one place
to another and then connect to existing plumbing. We have vague ideas about how “concentration
gradients” of special molecular markers lead to the growth of arms and legs and
the like, but really no idea at all how the body arranges for the bones of the
arm to grow into the humerus (upper arm) and then the radius and ulna (lower
arm), all of these looking remarkably similar in detail from one person to
another.
So I would caution against the “irrational exuberance” ( a Greenspan term) , or hubris, of thinking we
have understood the world and just have a few minor details remaining to work
out. Far from it, if all knowledge is
like a finished oil painting, at best we have only the beginnings of a
preliminary rough charcoal sketch of the finished work. In a 1000 years or so, if we are lucky enough to survive as a species that long, our current views of the world will no doubt seem absurdly childish and primitive.
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