Chapter 0: Science and Clear Thinking
The Bennett etal text
"Cosmic Perspective" covers some of the standard material on the
nature of science and scientific thinking, but I have some deeper
thoughts on this and the larger role of scientific thinking in the discovery
and evaluation of knowledge. Many of you will not have another science course.
So I've put together this personal essay on the subject of clear thinking
in general and scientific method in particular. A first
rate book for the intelligent layman on the nature of science, thought, and New-Age
mysticism is "The
Demon Haunted World" by Carl Sagan.
Einstein once said that the most incomprehensible
thing about the universe is that it is comprehensible. It's a great quote,
but it's worth pondering - how did he mean us to take that? I think it's actually
much easier to see why the universe would be comprehensible
1. Natural Selection and
the Development of Mind
The fossil record shows convincingly that
life evolves. There's an unbroken sequence of subtle changes in the DNA of all species of life on Earth, showing the accumlating changes which has marked the adaptation of species to the environments of the Earth. Darwin and Wallace showed that this evolution is guided by the
process of natural selection; members of a species are not born equal.
Some are better able to solve the problems of survival than others. To
Our human ability is the ability to observe
events, abstract from them general principles which appear to govern these
events, and further integrate these principles into wider knowledge in a way
which gives you that "light bulb" experience of non-contradictory synthesis of
understanding. Our brains signal errors by giving us that clashing "doesn't
fit" feeling, like when you stare at 2+2=5. Think about that... it's
really mental sensations that signal understanding vs contradiction. That's
getting pretty organic and pretty biological. Gray matter is doing all this!
What makes the issue confusing to some is that these perceptions and integrations
don't happen without intent and focus. Unlike many other animals, our brains,
especially the reasoning abilities, don't work very well unless one exerts
effort. It takes effort to make a conscious decision to think, focus, and
hold fast to the basic principle that the desire for truth takes precedence
over all other temptations (like, being proved "right", or impressing
someone else, or avoiding a painful realization, or indulging a questionable
desire, or indeed anything else). Consider...
skiing well requires great focus and effort but pays off with delightful feelings
(as long as you don't hit a tree)
Your brain produces the "light bulb"
feeling when you integrate a new understanding into your previous knowledge
without contradiction. And you get the "doesn't fit" clashing feeling
when you stare at an idea which conflicts with your current knowledge. This
dissonance is your organism's warning signal that you need to focus with greater
attention and clarity to resolve the conflict, that you're not yet in optimal
contact with Reality. And, that "light bulb" feeling of resolution
feels good when understanding finally comes! It's your organism's
reward for doing a good job at integration. Those who spend a lot of time
avoiding awareness by frying their brains on drugs, alcohol, and TV, don't realize the fun
and pleasure that your feelings give you when you do the right things mentally
(they're also confusing genuine pleasure with trying to numb out pain). We
evolved these feelings as motivation and reward for successfully coping.
Ask yourself how long a species would last if it were wired to give pleasure
when it acted self-destructively, or didn't experience pleasure when it did
things right. Avoiding the "pain" of effort or of sobering realizations,
is not the same as genuine pleasure, and a continued pattern of avoidance
of mental focus is a guaranteed path to deep anxiety and depression.
2. Using this in
Learning
Wise students will use this fact... look for the "light bulb" feeling as you learn. If you're not getting it during lecture, stop me and ask me to explain it another way. And here's another important point: Realize that when you focus on a problem, when you really try to make sense out of something, and when you really care about understanding it, then even if you don't immediately succeed, your subconscious will continue the process of integration. It may be a day or three or longer, depending on how tough the problem and how tenacious you are in your desire, but at some point the "light bulb" will go on. You'll be washing the dishes and all of a sudden - "Ahhh! now I get it!". Trust in this process and don't be easily discouraged when understanding isn't immediate. It will come, but only if you're genuinely interested and put for the energy of focus. Conversely, if you aren't really interested in understanding it, it probably won't happen. Deep inside, it's your true desire for clarity that will make or break this process. This is a big reason why people with a lot of curiosity do so much better at mastering new knowledge of all kinds. You have to care. Or all is lost in the quest for understanding.
Consider this - suppose you've NOT insisted on the "light bulb" experience before letting something become part of your brain's established knowledge base. Your mind is then like a jumble of jagged pieces of information, none of which fit together into a non-contradictory whole. What will it feel like if another contradiction is knocking at the door? I'll tell you - It'll feel no different than before! You'll have no means to judge truth. You'll not get that experiential signal that something is wrong. The state of your brain will be unchanged - still a jumble of puzzle pieces that don't fit together. Because you've never engaged the mechanism which tells you truth from falsehood. Now suppose you HAVE been careful in only letting in as knowledge that which fits without contradiction into your existing knowledge base. If a new piece comes in which doesn't fit, you get a strong "clash" experience, the non-light bulb. And this is your cue to look more closely and question. Either the new "knowledge" is false, or perhaps (tragically!) your whole paradigm is false. If you started building a mind built on nonsense too young, and then just kept feeding in more that reinforces it, you may have confused the "light bulb" experience with what is in fact merely the "this agrees with my prejudices and I don't want to look too closely at whether the whole is valid or not" experience. Telling the two apart if you've never experienced the "light bulb" may be tricky. I continue to ponder how best to show that to students... You may not always get a clear "llight bulb" if the concept is difficult. Very well, accept it in but with a big yellow flag on it. The flag being a sense that this is as yet verified in your own mind, but seems to come from a reliable source and so you'll accept it as provisional knowledge.
Here's another aspect of learning. Understanding
happens through the manipulation of your perceptions and internal representations
of reality - not of the outside world directly. There are three broad categories
that your internal representations can take: Visual
3. The "Real
World"
We live in an objective, external world.
In other words, we do not live in an ethereal personal dream/nightmare having
no connection with an external reality. This is easily proved - if you were
living in a dreamworld, you would not be able to successfully get your basic
life needs met so as to keep living. Also, if a person assumes otherwise,
then logically they're at a dead end and, believing their mind to be
Let's pause on the concept of a contradiction.
A contradiction is a statement with two or more ideas which are logically
incompatible. A contradiction is easiest to show in a closed system. Your
mind signals you that you're seeing a contradiction with a strong "that
does not compute!" experience, which has a different feel than
a "that disagrees with ideas which I've accepted but, to be
truthful, don't have a first-hand complete grasp of" feeling. A closed
system is a system of knowledge all of whose distinct, independent axioms
are specified, usually because they are defined by us. An open system is one
in which the principles are not defined by us and not necessarily completely
known. Mathematics is an example of
a closed system: For example, once we define the concepts of 2 and 4,
If contradictions do not exist, then there
is no explanatory power provided by the idea of a "supernatural".
There is only that which is real, whether discovered and understood yet or
not. That which is real will fit together without contradiction, and that
is also what we
4. Scientific Method
All of us, scientists or not, are constantly
making observations. Through your curiosity, eventually you notice a set of
apparently related phenomena and form a question about it. You then brainstorm,
coming up with any possible explanatory models. These models, at this point,
are called hypotheses. We haven't used any rigorous logic yet, and shouldn't.
This is the time to be as wild and crazy as possible. Maybe you'll have a
good long list at this point. Take your hunch of the best hypothesis and visualize
the meaning of it as clearly as possible, so that you can see what the observable
consequences would be. These observable consequences also need to be objectively
observable, meaning that they need to be visible to others in the outside
world. Then you test your hypothesis by designing an experiment which looks
for these consequences and distinguishes against other consequences. This
is where you have to be hard-headed and logical. If a hypothesis fails a test,
even just one test, then your hypothesis is ruled out. You breathe a sigh
of relief, you've made progress! The list of possible models is now shorter!
You keep this circle going until you find a hypothesis which passes all your
tests. A hypothesis which passes all tests so far put to it is called
a theory. At this point, if you're in the science
business, you may talk to your colleagues down the hall about your idea. If
they can't pick any holes in it, you're encouraged and take your show on the
road, giving guest colloquiums and seminars at other research centers. If
your theory's still standing, you write up a paper for publication in a peer-reviewed
scientific journal. This becomes an open invitation for all scientists to
see if they can devise new ways to test it. The first thing that is usually
done by other scientists, especially if the claim is important and suprising,
is to simply repeat your experiments. If they can't be repeated, then interest
usually fades. But if it's repeatable, and passes all tests that anyone can
devise, it may become part of the current paradigm; our "best current
theory". (In actual modern science, most work is done in collaborations,
each contributing their specialized talents to the effort. Still, the sketch
above gets across the real point)
The popular press often presents such a
theory as Final Truth. Scientists are clear in their own minds that their
latest theories are always subject to revision as new observations might require
in the future. The only requirement is that revised theories must agree
This brings up the next point. To stay well
connected to what's real, you have to develop a tolerance for uncertainty.
Or better, learn to love it, and appreciate the mystery! Those who are too
anxious for certainty often succumb to taking whatever idea seems most comfortable,
motivated more by the avoidance of anxiety than the desire for truth. On the
other hand, I see the foes of
The art of science is to use of your powers
of reasoning and observation to find the most promising ideas of how things
work, and to weed out what doesn't work.
Mistakes will always be made. But the method remains solid, and mistakes
are usually found quickly. This reminds me of another common truth; those
who are too afraid of making mistakes rarely do original, independent, and
ground-breaking work in science or anywhere else.
5. Steps of the
Scientific Method
1. Observations lead to a...
2. Question, on which
you brainstorm for a...
3. Hypothesis, which you then get logical and hard-headed about and...
4. Test for Observable
Consequences, which if failed, take you
back to #3, and if passed lead back to #4
over and over until
5. Theory!
Few ideas can be said with absolute finality
to be final "Truth", because it's usually impossible to know if
you've exhausted all possible tests or all possible alternate ideas. So, what
we seek is ways we can rule something out. For example, consider the Steady
State
Now here's two properties of a well formed
scientific theory or
1. It must be falsifiable
- meaning, there must be logical, observable consequences to this theory which,
if failing observational test, rule it out. If all conceivable
observations are compatible with the theory, then the theory is without consequences
and without intelligible content. An idea only has content to the extent that
it is observationally distinguished from other ideas. If
there is no distinction, there is no scientific content, even if on the surface it may
appear to be saying something.
2. At least some of its
observable consequences hopefully should be unique. That
means that no other known hypothesis produces the same observables.
From (1), we can hope to
rule it out if it's wrong, and from (2), we can hope, if it's right, to realize
it's a strong, realistic contender, justifying devoting our scarce resources of
time and money in further investigating it.
If your hypothesis has no observable consequences,
then it's is not within the realm of science! If none of your hypotheses about
a question have observable consequences, then the truth of falseness cannot
be determined. Your hypothesis in this case is called speculation.
For example, the claim that global warming is caused by some kind of unseen
energy waves from a civilization on the planet Krypton circling a star in
a distant galaxy, is not a scientific issue because we do not have the technology
to test the existence of such a civilization out there. Which doesn't mean
we can't find a sufficient explanation for global warming by looking at testable
ideas instead.
I emphasize that one doesn't need a hypthesis
about HOW an effect occurs in order to test whether it indeed occurs. This
is a common misunderstanding with beginning students in science. A classic
example is given by astrology. Natal astrology claims that your basic personality is influenced by the positions
of the sun, moon and planets at the time of your birth. This is a very testable
claim! It is premature to worry about HOW this influence can happen, and in
fact most astrologers don't try to explain how. The mechanism of the cause
is not important at this point. First test if the claimed association between
birth date/location and personality even exists. If it does, then (and only
then) would it indeed be fascinating to try to discover how this mechanism
works. Some, including our former text author Andrew Fraknoi, go off the rails
and bash astrology because the sun isn't even in the astrological signs claimed.
Well, so what? Since astrologers rarely try and claim a mechanism for why
astrology should work, how can anyone claim the this birth sign offset actually kills
astrology? It doesn't. What kills astrology is that there is
6. Pseudo-Science
"What I seek to accomplish is to serve, with my feeble capacity, truth and justice at the risk of pleasing no one" - Albert Einstein... (I know how he felt-RN)
When people use the trappings and jargon of
science to lend an aura of credibility and high-mindedness to an otherwise
bogus body of thought, we call this a pseudo-science. Pseudo-science is not hard to find at any bookstore. Healing crystals,
As for distinguishing the "light
bulb" feeling from the "feelgood" feeling... the "light
bulb" feeling follows from a state of concentrated awareness and desire
for clarity, and from the act of integrating new knowledge into carefully
assembled existing knowledge without contradiction. The "feelgood"
feelings don't. There's an uneasy quality of awareness avoidance that's just under the surface. But ultimately, you'll only know the difference from
your personal experience. We are all human and we all feel the sway of both
at times. The wise person observes which is which. Certainly scientists can get attached to their pet theories as well.
The difference is, if they let their attachment ruin their objectivity, they
lose credibility, can no longer win grants, and other scientists will no longer
take the effort to study their work. It's the ruthless logic of the scientific
method which ultimately disciplines the field. Good scientists know that they
sometimes must witness the "murder of beautiful theories by ugly facts",
as it's humorously been put by scientists themselves. This isn't to say that
there aren't wonderful insights to our understanding
of life and the universe in some New Age material. Particularly in psychology
- a very challenging young science since it demands incredible maturity and
objectivity in that the subject of study is also the object of study - the
mind and emotions. I believe academic psychology is often too simplistic,
and the important advances have come from out of "left field", or
what seemed like left field when first advanced.
I've always been curious about the motivations
behind the popularity of so much pseudoscience. One motive I've heard is the
feeling that scientists take all the magic out of life, reducing it to cold
statistics. But this misunderstands science as nothing but factoids. Instead,
consider the incredible discoveries of the last decade in my own field of
astronomy. The astronomers I know will, every one, tell you their own experience
is that, in the words of Jules Verne, "Reality provides us with facts so romantic that imagination
itself could add nothing to them".
7. General Principles in
the Design of a Scientific Test
Astronomy is a bit unusual in that there's
rarely a chance to set up situations and do full-bore scientific testing like I
describe below. But for most of you, these ideas below will be important to
consider in, for example, evaluating the truth of medical claims. Something we
all are exposed to.... Suppose you are to design an experiment to test the
claim that taking beta carotene supplements will reduce the incidence of cancer
(to take a currently publicized example). Here's some guidelines...
You'll want to get a sample of people and
give half of them beta carotene and half a placebo. A placebo, in this case,
would be a pill that looks like a beta carotene pill but is in fact some inert
ingredient already shown to be unrelated to cancer. Here's some
a. The placebo effect. The mind powerfully affects the body. Our thoughts and feelings
affect health in ways we only are beginning to understand. If someone believes
beta carotene works, and they take a pill they think is beta carotene, they may
in fact induce poorly understood internal processes which may in fact lower
their probability of getting cancer. More commonly, expectation has a huge
effect on the perception of pain. Even "physical" pain has a large
psychological component. Pain, after all, is our bodies signal to our
conscience mind to "do something - we're in danger". Once you
believed you've done something useful (like taking a pill you believe will
help, even if it is actually just a sugar pill), then your perceived pain can
drop noticeably. This is why illnesses whose only symptoms are subjective
perceptions (e.g. chronic fatigue syndrome) require very careful science in
order to evaluate properly. Both of these aspects are called the placebo
effect. To guard against mistakenly assuming the healing was caused by beta
carotene, you must be sure that not only does the subject not know which pill
has beta carotene, but neither does the person giving him the pills. If the
doctor knows he's giving placebos to one group and real pills to another, some
subtle mannerisms may betray this. A study done this way is called a
"double blind" study.
b. Proper controls. A controlled study is a study where great care is taken to insure
that any other factors which could conceivably affect the outcome are identified
and kept constant so that the only variable is the one which you are testing.
One way this is done in medicine is to match subjects in pairs. Divide your
subject sample in half, and pair up each person with another who is as nearly
identical in relevant aspects as possible. Then for all pairs, give one the
real medicine and one the placebo. For example, suppose the cancers you're
testing occur in women more than men. If you don't separately record the gender
of each subject and properly match the test subjects with the placebo subjects,
then you could mistakenly infer an effect due to beta carotene which is in
fact due to gender differences.
c. Sufficient sample size. There may be many causes
for cancer. Our hypothesis is only that beta carotene will reduce cancer incidence,
not eliminate it. If Aunt Mabel takes her beta carotene every day and lives
to age 100 before she dies of kidney failure, this is NOT
d. Random sample selection. You must be sure your
sample is random with respect to what you're measuring. If you're measuring
the occurance rate of breast cancer in the U.S., you'd want to select people
randomly from the entire U.S. population. You wouldn't want to go to the cancer
ward at the local hospital to find your volunteers; you'll get a very alarming
cancer rate! If you're testing the pain-control effect of some new medicine,
you wouldn't want to go to a New Age health conference to get your subject
sample - you'll probably get an exagerated placebo effect to try and disentangle.
e. Sufficient time. Run the test as long as you believe the effect could take to
appear. For cancer, we know it may take many years from cause to malignancy.
f. "Associated"
does not necessarily mean "caused". This one is really unappreciated by the popular press. You may assume
one thing caused another, when in fact both things are caused by a third.
The mind itself will be very tempted to do this. In the simpler world of most
of our evolution, it was handy to make snap judgements that if Y followed
X, then Y was probably caused by X. So be careful. Suppose you do a study
and find with high statistical significance
g. Don't overinterpret the data. This one is a common pit-fall lurking in alternative medical claims. For example, it can be tempting to look at, say, a medical practice which provides symptom relief and assume this provides support for an entire paradigm which includes this practice. Yet the medical practice itself may have no logically necessary relation to the paradigm. Consider a Native American practice of grinding and eating willow tree bark to banish the evil spirits showing themselves as what we'd call inflamation and pain. And you find with good scientific tests that this willow tree bark really does lead to pain relief far beyond that predicted by random chance after controlling for placebo etc. Does this provide support for the evil spirit paradigm? No, it only provides support that this willow bark can relieve pain. Maybe it's the salacylic acid (aspirin!) which is found in willow bark which is the active ingredient.
8. Occam's Razor
This is a principle in science named after
Lord William of Occam. We've noticed over and over that, given two or more
explanations, all of which explain the observations, the one which ultimately
will most likely pass the tests is the one which requires the least changes
to current thinking. In other words, "simpler is usually truer".
Perhaps the ultimate reason that this seems to be true is that our brains
really are evolved to work well at understanding nature. The converse is that
"extraordinary claims require extraordinary evidence" (a famous
quote of Carl Sagan). Occam's Razor is what chops down the UFO sightings.
99%+ of UFO sightings can be explained more simply as e.g. the planet Venus
twinkling through turbulent air, or large meteors or military aircraft, ball
lightening, wishful thinking, etc.... if not out-right hoaxes. The alien abductee
stories can be more simply explained as attention- (or money-) getting frauds, or self-induced hypnosis. Also,
the relaying of the story from source to eventual publication often gets subtly,
or not so subtly, distorted.... The old "fish story" phenomenon.
To be a bit more charitable, most people
don't appreciate how much our expectations influence how they "see"
what they see. Too often we see what we expect to see. Go to the Exploratorium
in San Francisco, or the Mystery Spot up in the mountains here to
see this in action. And listen to this wonderfully entertaining episode of
RadioLab
(use the slider and click on "Stochasticity"). The brain so much
wants to make sense out of what it perceives that if that person has no prior
category for the sensory input, it'll force it into a category more familiar
(even if only from the National Enquirer). Magicians use this to
their advantage. Most people don't understand how differential refraction
causes bright objects like Venus or Sirius to rapidly twinkle through many
colors, so they think they're seeing flashing lights of an alien spaceship
(since everybody's seen Spielberg's "Close Encounters" and similar
movies). I and other astronomers I know will be quite happily amazed and delighted
if someone proves indeed that aliens have or are visiting Earth. Till then,
I'll keep my hand on my wallet.