Biology Reference
In-Depth Information
accommodate new data and new ideas. It is this openness to change that explains
why science is so successful at understanding the world.
Let me be very clear about this -
science is the most successful human endeavour
in history.
Despite all the problems in the world, it is the case that never before
in human history have so many people been so well fed, and have had so many
opportunities to lead long, healthy and interesting lives. These advances stem from
the application of scientific ideas and discoveries.
Science works
, so it may seem
surprising that scientific knowledge is not certain in an absolute sense. Why is this?
It is because you cannot predict the future. You can never be certain that even
long-held and very successful scientific ideas will not change as a result of future
discoveries. Even if you had a theory that was completely correct, you could never
be sure that this was the case, because you could never be certain that future
discoveries would not falsify it. Let me give you an example:-
In 1687 Isaac Newton published his master work that marks the beginning of
science in the Western world - the
Principia Mathematica.
This was the first topic
to propose general natural laws in a quantitative fashion. Newton's laws of motion
and his equations that describe gravity are incredibly successful and precise - pre-
cise enough to be used to send astronauts to the Moon and to land spacecraft on
the planet Mars. Nevertheless, the concepts on which Newton based his laws of
motion were shown to be incorrect just over 200 years later by Albert Einstein in
1905. Newton's concepts with respect to motion are wrong because he supposed
that time and space are absolute and independent - this agrees with our common-
sense perceptions of time and space. Einstein had the genius to realise that because
experiments show that the velocity of light is constant, irrespective of the veloc-
ity of the light source
,
this view must be wrong - time and space are relative to
one another, not independent. Experiments done since Einstein's time show that the
faster a clock moves, the slower it ticks and that the faster an object moves, the heav-
ier it becomes. In other words, our common-sense perceptions of time and space are
wrong. Newton's laws of motion work well enough in practice because relativistic
effects become significant only at velocities much faster than the ones we normally
have to deal with. These effects impact on human affairs only in the design of par-
ticle accelerators that would not work unless the relativistic effects were taken into
account in their design.
So here we have an example of a very successful scientific theory that was
accepted for over 200 years, but whose basic concepts, on which the Industrial
Revolution was partly founded, are now known to be incorrect.
Science is a uniquely
successful human activity precisely because it employs this inbuilt, self-correcting
mechanism.
So certainty is an illusion. Scientific knowledge is not a fixed desti-
nation but a moving target. This is why media commentators discussing science
who use the word “proof” demonstrate that they do not understand how science
works. In science, proof is not an option. Disproof on the other hand
is
an option-
if we discovered human fossils in rocks older than the rocks containing dinosaurs,
our current ideas about the evolution of mammals would be instantly disproved.
Einstein famously said that no amount of experiments could prove him correct, but
a single experiment could prove him wrong. So if you crave certainty, you will not
