Lesson 11: The Nature of Science
In this lesson, we will learn about the scientific method and what defines
scientific thinking. We will also learn about an idea known as Occam"s Razor,
and discuss how scientific theory differs from theories in everyday life.
Finally, we will look at some common misconceptions that do not stand up to
scientific thinking, and talk about the difference between astrology and
astronomy.
How do we distinguish science from non-science?
Not all science works the same way so it can be difficult to use one method to
define science. The scientific method, however, is commonly seen as an ideal
implementation of science. This process usually begins with making
observations, that lead to questions, and then hypotheses or educated guesses,
followed by predictions and then tests to confirm or observe. If the test
supports the hypothesis, then you can make additional predictions and test
them. If the test does not support the hypothesis, you will need to revise the
hypothesis or come up with a new one.
In real life, however,
science rarely progresses as neatly as idealized in the scientific method.
If scientific thinking does not always look like the scientific method,
how do we define it?
One way is to list the criteria that
scientists use when they judge competing models of nature. The hallmarks of
science include:
* Natural causes - modern science seeks explanations for observed phenomena that
rely upon natural causes only.
* Models of nature - science progresses through the creation and
testing of models of nature that explain these observations.
* Testable predictions - a scientific model must make testable predictions
about natural phenomena that would force us to abandon or revise the model if
the predictions did NOT agree with the observations.
Science seeks to explain observed phenomena using testable models of nature that
explain the observations as simply as possible.
Occam's Razor, named after William of Occam, a medieval scholar,
was the idea that scientists would prefer the simpler of two models that
agree well with scientific observations.
An example of this is the Copernican model versus the Ptolemy model. If
Copernicus's model had been evaluated solely on the accuracy of its
predictions, it would have had no real advantage over the long-established
Ptolemy model. But since it had a simpler explanation for some questions such
as apparent retrograde motion, it appealed to enough scientists that it
continued to get serious consideration and eventually Kepler was able to make
it work.
While individual scientists may carry personal biases, the collective action of
many scientists should make science objective. Some results could be affected
by personal biases, but as other people come along and continue to test the
results, they will eventually uncover mistakes.
A scientific theory is a simple yet powerful model whose predictions have been
borne out of repeated and varied testing. The everyday meaning of "theory" is
closer to hypothesis or speculation, but in scientific terminology, a theory is
considered practically a fact. While scientific theories can never be proven
true beyond all doubt, they are supported by a large, compelling body of
evidence.
For a long time, ancient people including Greek philosophers believed that the
Earth was flat. Around 240 B.C., a Greek scientist named Eratosthenes first
measured the Earth's circumference and proved that it was round. It was already
common belief that the Earth was spherical by that time, but his findings
confirmed it as fact.
Another common misconception in more recent years is that you can balance an
egg on its end during the spring equinox and that this is the only day in the
year that you can do this. This is a myth. The equinox is just a point in time
when sunlight strikes both hemispheres equally. It is difficult to see how
sunlight could affect an attempt to balance eggs as there is nothing different
about Earth's gravity or the Sun's gravity that day.
Although it takes a lot of practice to balance an egg, you could try it
yourself and you would discover that an egg can be balanced on its end any day
of the year. The basic lesson here is that prior to accepting any 'claim,' you
can and should demand reasonable proof or an explanation with evidence to back
it up!
Astrology is the study of human behavior and events based on the movement of
the Sun, Moon, and planets. For a long time, astrology and astronomy went hand
in hand, but today, they are considered two very different things.
Although astrology is still practiced by many people,
it is not a science since it cannot be tested or proven. It has also been
unable to explain natural phenomena or consistently make future predictions.