Today I want to talk about the nature of science,
and the difference between real science and pseudoscience.
You've probably heard of the scientific method
where a researcher formulates a question,
and then develops a hypothesis, then makes
a prediction, and then designs an experiment
to test the prediction.
The scientific method sounds very official
and very clean, but the way science progresses
is often much messier than this. Scientific
discoveries can begin with observations and
then figuring things out from the observations,
like Galileo looking at the sky with his telescope.
Science doesn't always proceed in an orderly
fashion. It can be chaotic, and crazy, and
surprising, and beautiful all at once.
Nevertheless, there are a few basic characteristics
we can use to distinguish real science from
pseudoscience or "false science".
First, real science seeks explanations that
rely solely on natural causes. Nothing supernatural
is allowed.
Second, science moves forward through the
creation and testing of models of nature that
explain observations as simply as possible.
There's a principle called Occam's razor,
named for the medieval scholar, William of
Ockham. Occam's razor says 'all things being
equal, the simplest explanation is usually
the correct one'.
A third characteristic of true science is
that a scientific model must make testable
predictions about it is we're observing. If
the observations don't match what the model
predicted, then we must revise or abandon
our model.
This third characteristic is an important
one. I often get asked by students and the
public big questions about astronomy, like
"what was there before the universe began?"
or "are we living in a computer simulation?"
These are great questions, but the problem
is, what sort of experiment could we design
to test these ideas?
So a scientific idea must be testable. It
must also be verifiable.
For example, if your best friend tells you
she has come up with a way to do cold fusion
in her kitchen, her experiment is not scientific
until others can reproduce what she's done.
Scientists are human, and can often be biases,
but requiring repeatability of measurements
is one way to keep people honest.
If we think about the characteristics of science,
the difference between science and pseudoscience
starts to become quite clear.
Things like astrology and psychics, or alien
abductions are all pseudoscience. They all
invoke the supernatural. They all have very
complicated explanations, and none have ever
been verified. Some pseudoscience isn't even
testable.
Finally I want to talk about what is meant
by a scientific theory. By definition, a scientific
theory is a model of some aspect of nature
that has been rigorously tested and has passed
all tests to date.
A scientific theory can't be proven beyond
all doubt because future observations may
disagree with its predictions. Nevertheless,
anything that qualifies as a scientific theory
must be supported by a preponderance of evidence.
Modern evolution and Einstein's theory of
relativity are examples of scientific theories.
That's just a little bit on the nature of
science. I hope it was helpful. I'm going
to go test my hypothesis that getting a soy
latte will make me happy. I'll talk to you
again soon.
