Chapter 15 Science and Pseudoscience Critical Thinking Chapter 15 Science and Pseudoscience Lecture Notes © 2008 McGraw Hill Higher Education

1 The Basic Pattern of Scientific Reasoning Identifying the Problem: In order for science to be useful, the problem will have to be “testable”; it can’t be unobservable. Gathering Relevant Data: Sometimes, one observation will do it but most often many observations are needed. Formulating Hypotheses: Random data gathering won’t do; you need an “educated guess” (hypothesis) to direct you. Testing the Hypothesis: If it turns out that the universe isn’t a way which the hypothesis predicts, the hypothesis is disconfirmed and we reject it. However, the more of the world is observed to be like the hypothesis predicts, the more confirmed the hypothesis will be. But since we could never observe the whole universe—especially not the future— no hypothesis will ever be proven. Every time something falls to the ground, it adds conformation to the theory of gravity. But it is always possible—although unlikely—that tomorrow things will start “falling up.” Lecture Notes © 2008 McGraw Hill Higher Education

1.2 More on Hypothesis Testing A Controlled Study: A study where a randomly selected group is divided into a experimental group and a control group, and only one group is subject to the experimental condition. Randomized Experimental Study: Find a group that has already been exposed to the experimental condition, and compare it to one that has not but that is similar in all other relevant respects. Lecture Notes © 2008 McGraw Hill Higher Education

2 The Limitations of Science Science cannot answer: Questions of meaning: Does the universe or life have a purpose? Does my suffering have meaning? Questions of value: Is abortion morally wrong? Is freedom more important than equality? Lecture Notes © 2008 McGraw Hill Higher Education

3 How to distinguish Science from Pseudoscience. Pseudoscience is false science. It appears to be science but is not. Six marks of Pseudoscience It makes claims that are not testable. It makes claims that are inconsistent with well-established scientific truths. It explains away or ignores falsifying data. It uses vague language. It is not progressive. It often involves no serious effort to conduct research. Lecture Notes © 2008 McGraw Hill Higher Education

3.1 Absence of Testability A claim (hypothesis) is testable when we can make observations that would show it to be true or false (i.e., when the hypothesis “predicts” that the universe will be a certain way). Essentially it must be testable in principle. This is only true if it is two things: Verifiable in principle: There is an observation that would support it. Falsifiable in principle: There is an observation that would disconfirm it. Lecture Notes © 2008 McGraw Hill Higher Education

3.1 Absence of Testability Pseudoscientists often fail to provide falsifiable claims. They “explain away” any disconfirming evidence. “Extrasensory perception exists, but doesn’t work in the presence of skeptics.” All matter in the universe is moved by tiny elves that always—when they are about to be observed—hide. Could you observe anything to prove this false? Lecture Notes © 2008 McGraw Hill Higher Education

3.2 Explaining Away or Ignoring Falsifying Evidence Pseudoscience will ignore falsifying evidence, protecting “pet” theories. You caught the “telekinetic psychic” cheating on camera? Well, he only cheats when his powers aren’t working. Lecture Notes © 2008 McGraw Hill Higher Education

Lecture Notes © 2008 McGraw Hill Higher Education 3.3 Use of Vague Language Scientific hypotheses must be specific and make specific predictions. Cold reading: gathering obvious general information about a subject and then repeating in a vague form as if you “just knew it.” (e.g., psychic readings) Fishing for Details: Multiple-out expressions: expressions so vague that an interpretation of them is true of nearly anyone. (e.g., “someone close to you is having problems in his or her love life.”) Try-ons: something worded so that, if correct, it will be remembered as “remarkable” but, if not, will be forgotten. (e.g., I’m getting a feeling you may have some serious financial concerns.”) Lecture Notes © 2008 McGraw Hill Higher Education

3.4 Lack of Progressiveness Science changes as hypothesis are confirmed or shown false. If a “science” has not changed for many years, it is likely pseudoscience. For example, people who still believe the earth is flat. Lecture Notes © 2008 McGraw Hill Higher Education

3.5 Failure to Conduct Research Scientists are always driven to research—to make observations that will either falsify or support their theory. If a “science” fails to do this, then it is a pseudoscience. Examples: The water cure theory. (They actually deny the need for research.) The flat earth theory. (If they really were concerned with the truth, they would send up their own satellite to take pictures and prove that they are right.) Lecture Notes © 2008 McGraw Hill Higher Education

4 Case Study: Astrology (Self-reading) Astrologers claim that human personality, behavior, and destiny are all strongly influenced by the position of the sun, moon, planets, and stars at the time of one’s birth. Astrology, however, has no scientific basis. Let’s look at why… Lecture Notes © 2008 McGraw Hill Higher Education

4.1 Astrology is Pseudoscience because… Astrologers Fail to Identify a Plausible Physical Force or Mechanism. The causal force used to be the “Greek gods,” (what god you were “born under” made a difference in your destiny). No force that celestial bodies have—gravity, magnetic field, etc. —produce a significant effect on any earthy thing. (Your desk has more gravitational effect on you than Venus.) Lecture Notes © 2008 McGraw Hill Higher Education

4.2 Astrology is Pseudoscience because… The Problem of Precession: As earth “wobbles” in its orbit, the position of the stars change. Astrologers have failed to compensate for this fact. Lecture Notes © 2008 McGraw Hill Higher Education

4.3 Astrology is Pseudoscience because… Astrology is Not Progressive: it has not accounted for new data. New planets have been discovered. They are now figured into astrological calculations. However, shouldn’t they have been before? Their effect is not contingent on our awareness of them (so they claim). So shouldn’t have old predictions been off? There are other bodies (moons, asteroids) that are much closer and/or bigger than other bodies that supposedly have an effect (Pluto, Mercury). Why don’t these bigger and/or closer bodies have an effect? Constellations change over time. The stars that make up the constellation Leo used to not look like a Lion, and later won’t again. And yet the personality you have, if born under Leo, is somehow derived from the fact that it looks like a lion? Lecture Notes © 2008 McGraw Hill Higher Education

4.4 Astrology is Pseudoscience because… Astrology used Vague, Untestable Language. “If you’re stubborn enough to keep going you may still achieve your goals. The longer you hang on, the more likely you are to achieve your goals.” I “may”? This will be true no matter what happens. It’s true by definition that the longer you do something, the more likely you are to succeed. This is so vague that it applies to pretty much anyone. Lecture Notes © 2008 McGraw Hill Higher Education

4.5 Astrology is Pseudoscience because… If one’s destiny is set by the stars, there shouldn’t be any “mixing of destinies.” If a Leo dies in an accident one would expect many Leos to die in an accident at the same time, but people of other signs to be safe. But this is clearly not the case. There were people of all signs aboard the Titanic—yet they nearly all had the same fate. Seems like what ship you decide to board has a lot more to do with your destiny than where the stars, planets and sun were when you were born. Lecture Notes © 2008 McGraw Hill Higher Education

4.6 Astrology is Pseudoscience because… Scientific Tests do not Support Astrology’s Claims. Representative studies have been done comparing sun signs (and other signs) to people’s appearance, relationships, vocation, and personality. None of them showed any correlation between the two. (One could do just as well predicting your personality by throwing darts at a “personality dart board.”) Lecture Notes © 2008 McGraw Hill Higher Education

Lecture Notes © 2008 McGraw Hill Higher Education Tutorial 15.3, marked ones, any 5, individual work Lecture Notes © 2008 McGraw Hill Higher Education