Anyone who conducts
an argument by appealing to Authority is not using his intelligence,
he is just using his memory.
– Leonardo da Vinci
Irrationally held truths may be more harmful than
– T.H. Huxley
External Links page.
What Is Science?
- In short: An organized,
logical method to obtain knowledge about the natural world; Uses
careful observation, reasoning, and/or experiment; Produces models
("explanations"), predictions (which must be falsifiable,
so they test the models and may lead to their revision), and
- Tools: Observation (collecting
facts as objectively as possible; not always obvious!); Logic
and math; Intuition, "insight", dialogue, luck; Guided
by paradigms and "fashions".
- Stages: A common pattern is
Observation –> Model / Hypothesis –> Predictions –> Test
/ Experiment; Experiments are new observations that can lead to changes
the models; The pattern refers to the logical development
of science, sometimes to what scientists actually do in their work;
It is not possible to reduce that to a set of steps, and in that
sense "doing science" is a creative activity, but one that
must follow rules of logic.
- Theories: After
repeated testing of its predictions, a theory becomes accepted; While
a theory can never be proven "true", a successful one is
an overarching explanation that accounts well for known facts, hypotheses,
and observations whithin its range of applicability;
in this sense, a scientific theory
is not "just
It must also include ways of disproving it, and almost every theory
is eventually superseded by a better one.
Development of Science
- Historically: Developed over
many centuries, with different key contributions.
- Ancient Greece: Greek culture was superstitious
and had a large irrational component, but it also developed a naturalistic
philosophy and interpretation of the universe (as opposed to
mystic), in which knowledge of geometry played a prominent role; We can
describe nature by using conceptual models.
- Modern view: Started in the XV century,
with Renaissance Europeans assimilating Eastern and Arabic knowledge
and accumulated observational records; We can understand nature
by using physical laws.
- Technological advances: We can
reach out and become more actively involved, manipulate nature.
- Today's debates: We can push
our reliance on our intellect all the way to questioning the
reason for our existence and the origin of the universe.
- Role of astronomy: Astronomy
has been one of the disciplines with the greatest impact on the
development of science, because of its strong ties to practical aspects
human life from ancient times, as reflected for example in our calendar,
and to the Big Questions (which it can't really answer, but it can
provide a context to them).
What Kinds of Statements
Does Science Make?
- Observed facts: The fact that
a planet has (at least) a certain number of moons.
- Interpreted facts: Jupiter has
dark cloud "belts" and lighter "zones"; For
decades, it was (apparently) falsely believed that the belts
were made of sinking gas, and the zones of rising gas, by analogy
with Earth features.
- Is science objective? Facts do "speak
for themselves", but we don't always understand what they say,
and scientists often cannot help being influenced by cognitive barriers
that cloud our judgment.
- Scientific statements: They
are not really to be taken as "bits of the truth";
Science is more like a search for laws and descriptions that
work, and reflects our best ability to understand and model natural
- Limits of science: Any scientific
statement may need to be replaced if it turns out that the assumptions
it used are not correct, or better data become available. But
we do not always replace a scientific statement whose limits
of validity are known. A theory can be very useful even if we
know it is wrong, provided we use it in a context where it provides
a good approximation; For example, planets do not really
orbit the Sun along ellipses.
- Science and religion: For an example
of a point in which the approaches differ, read the responses to a
question on scientific dating vs Biblical dating posted
Compared to Pseudocience
- Pseudoscience: Makes non-scientific
claims but tries to pass them off as science, in an attempt to
convince people of their truth. Similar to bad science, which
makes scientific claims which contradict the facts (either by
mistake, or as the result of a deliberate attempt to mislead).
Both are a problem; they are relatively easy to uncover (for example,
psychics' predictions are almost always wrong), if one knows about
them, but it is difficult to stop people from making
claims or believing in those claims (37% of Americans believe that "houses
can be haunted"!). Education is the best answer.
- Nonscience: Does not deal with
testable predictions, but faith and tradition. Science and nonscience
do not contradict each other, since they deal with different
questions, and can live alongside each other.
- Examples: Canals on Mars, ESP,
UFO's; Bending of spoons, magnetic bracelets, and the like; But what
about the anthropic principle, or the multiverse idea? Distinctions
- What it is: The belief that
the positions of celestial objects like the planets and stars
can affect lives of individuals, or can be interpreted as indications
of future events.
- Historically: Centuries ago
the monitoring of positions of stars and planets, and their use
in predicting effects on human lives, was a popular activity.
Many decisions were taken based on them (assassination of Caesar,
...). Many astronomers, Kepler included, were also astrologers.
- Examples: Position of stars
and planets at birth; Planetary alignments.
- Today: Considered pseudoscience,
or non-science if it does not try to make predictions.
- Fact: Astrology holds little,
if any, predictive power. Not a shred of evidence (other than
indirectly through weather, ...) that star and planet positions or alignments
have ever had any consequences, and many reasons to doubt it.
(The position of the doctor and nurse at your birth are far more
important than those of the planets!)
- Titius-Bode law: The distances
of the planets (and asteroid belt) from the Sun, in astronomical
units, can be obtained from the sequence of numbers 0, 3, 6,
12, 24 by adding 4 and dividing the result by 10.
- Kepler's Period Law: The distances
of the planets (and asteroid belt) from the Sun, in astronomical
units, can be obtained by taking the third power of the periods
of their orbits, in Earth years, and taking the square root of
- Assessment: What does science
make of statements like these?
What is a good model for
the Solar System?
- Conclusion: Our brains have evolved
pattern-recognition machines; Science is an attempt to systematically
pursue the fruitful ones, and it requires training; Scientists do have
their prejudices, however; Up to the 1920's everybody "knew"
the universe was static, and until the 1990's that its expansion
was slowing down; But eventually...
page by luca bombelli <bombelli at olemiss.edu>,
modified 29 sep 2012