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HOW DO YOU KNOW WHAT YOU KNOW? Or at least what you think you know?

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Presentation on theme: "HOW DO YOU KNOW WHAT YOU KNOW? Or at least what you think you know?"— Presentation transcript:

1 HOW DO YOU KNOW WHAT YOU KNOW? Or at least what you think you know?

2 WHAT DOES IT MEAN TO “KNOW” SOMETHING?
1. Personal Experience through the five senses. I know a bee sting hurts; I know how to ride a bike. 2. Reliance on Authority. I know the sun is 93 million miles away; Jesus loves me, this I know, for the Bible tells me so. 3. Logic. I know 2 million + 2 million = 4 million, even though I’ve never counted that high. I know I have a brain, even though I’ve never seen it. 4. Feeling or Intuition. I know she’s the one for me; I know God has called me to the ministry. Two things that people pretend are knowledge, but they really aren’t: 6. Bluffing (lying) - you try to persuade others for an ulterior motive. You should buy these tickets from me because I know this team is going to the Super Bowl this year; I know this bone is from an ape-man. 5. Wishful Thinking (you really want it to be true) I just know I’m going to win the lottery!

3 WHAT CAN YOU BE ABSOLUTELY CERTAIN OF?
If someone tells you “There is no such thing as absolute truth,” ask them: Are you absolutely sure? The concept that each observer creates his own reality is not scientific, but religious! The question of whether there is absolute truth is philosophical rather than scientific. There could be absolute truth – but we can’t find it through science.

4 WHAT DOES IT MEAN TO “KNOW” SOMETHING?
1. Personal Experience through the five senses. I know a bee sting hurts; I know how to ride a bike. 2. Reliance on Authority. I know the sun is 93 million miles away; Jesus loves me, this I know, for the Bible tells me so. 3. Logic. I know 2 million + 2 million = 4 million, even though I’ve never counted that high. I know I have a brain, even though I’ve never seen it. 4. Feeling or Intuition. I know she’s the one for me; I know God has called me to the ministry. Two things that people pretend are knowledge, but they really aren’t: 6. Bluffing (lying) - you try to persuade others for an ulterior motive. You should buy these tickets from me because I know this team is going to the Super Bowl this year; I know this bone is from an ape-man. 5. Wishful Thinking (you really want it to be true) I just know I’m going to win the lottery!

5 REASONS TO BELIEVE OTHERS WHO TRY TO PERSUADE US OF WHAT THEY “KNOW”
IS IT BECAUSE: (1) They claim to have personal experience, OR (2) They appeal to an authority we trust, OR (3) We have checked out their logic and found it trustworthy? OR are we willing to trust their (4) intuition, (5) wishful thinking, or (6) bluffing?

6 DOES MEMORIZATION HAVE A PLACE IN SCIENCE (and science classes)?
Yes! It is part of the knowledge we have by authority. It would be a great waste of time if you had to continually look up how much two plus two adds up to, or if you continually had to rediscover Newton’s Laws ( f = m a, etc.) But if all we did was memorize, we would never gain new knowledge that did not exist before.

7 This is the basis of mathematics, NOT science.
THE TWO TYPES OF LOGIC 1. INDUCTIVE. Look at many phenomena and try to discover a pattern that points to a general principle. Inductive logic tries to determine the most reasonable (most likely) conclusion. This is the heart of the scientific method. 2. DEDUCTIVE. Start with general principles accepted as true and apply them to specific cases. Deductive logic tries to establish absolute truth, i.e., the conclusion MUST be true. This is the basis of mathematics, NOT science.

8 CONTRASTING LOGIC The conclusions of inductive logic result
from examination of observable phenomena (a posteriori). They are testable. The premises of deductive logic may come from inductive conclusions, or they may just be statements accepted as self-evident (a priori). They are not necessarily the result of testing.

9 EVEN WITH CORRECT LOGIC, FALSE PREMISES CAN LEAD TO FALSE CONCLUSIONS.
All dogs bark. (Or, “If an animal is a dog, then it barks.”) Snoopy is a dog. Therefore, Snoopy barks. Not if Snoopy is a Basenji! Basenjis do not bark. If any one of our premises is wrong, then our conclusion is unreliable.

10 POSTULATES - Statements that are taken as self-evident and accepted without proof.
Euclid’s Parallel Line Postulate says that for any line, there can be only one parallel line through a point not on the first line. Point not on the first line Only one parallel line First line BUT IS IT REALLY SELF-EVIDENT? Lobachevskyan and Riemannian geometry say that space is curved, so there is no such thing as an infinitely long straight line in the sense that we understand “straight.” One says space is negatively curved so that there are an infinite number of parallel lines through a point not on a line. The other says space is positively curved so that there are no parallel lines. All lines intersect at infinity. EACH OF THE THREE IS THE BASIS OF A DIFFERENT VERSION OF GEOMETRY, BUT NONE CAN BE PROVEN.

11 “SCIENCE” UNTIL THE MIDDLE AGES:
Based on the deductive logic of the ancient Greeks, who believed that logic always leads to truth. Testing was unimportant to them. Most famous Greek philosopher: Aristotle (inventor of the logic still used today), whose ideas were taught as fact for about 2,000 years throughout Europe, west Asia, and Africa.

12 EXAMPLES OF INCORRECT CONCLUSIONS BASED ON FAULTY DEDUCTIVE LOGIC
“Scientific” ideas of Aristotle TAUGHT AS FACT in European Universities for 2000 YEARS: 1. The earth is the center of the solar system. Falsified by Copernicus. 2. Heavier objects fall faster. Falsified by Galileo. 3. All objects possess an innate tendency to come to rest. Falsified by Newton. 4. There is no such thing as an atom. Falsified by many modern scientists.

13 ARISTOTLE’S MOST BASIC MISTAKE IN LOGIC:
1. He reasoned that if the stars were different distances, they should display parallax. 2. He could not detect any parallax. 3. Therefore he decided “If I cannot see parallax then it does not exist.” Assuming there was no parallax led him to be wrong about EVERYTHING ELSE!

14 ARE YOU WILLING TO “UN-LEARN” SOME OF THE THINGS YOU HAVE LEARNED?
Aristotle was wrong because he started with the assumption that if he could not see something then it did not exist. This has happened in later years too. Wiedersheim and “vestigial organs” (function of appendix identified in peer-reviewed 2007 article from Duke University Medical School) 2. Schrödinger with his “quantum cat” related to radioactive decay (radioactive decay rates found to vary predictably every month -- Stanford Univ. 2010) 3. Many segments of DNA formerly called “pseudogenes” now have a known function. They are not “junk DNA” after all. THERE MAY BE MANY OTHER THINGS WE DON’T KNOW YET.

15 SKEPTICISM! ONE OF THE MOST IMPORTANT CHARACTERISTICS OF A SCIENTIST:
While most scientific progress occurs as we build on the work of others, the great leaps forward usually happen because someone doubted what almost everybody else thought. There is NOTHING in science that is above question. (Even gravity!)

16 Present + Repeatable + Observable = SCIENCE Past + Non-Repeatable + Eyewitness Account = HISTORY Past + Non-Repeatable + No Eyewitnesses = BELIEF

17 THE SCIENTIFIC METHOD 1. Define the problem. What do you want to know?
(E.g. “Does music affect how plants grow?”) 2. Gather information about the subject. (AUTHORITY) 3. Formulate a hypothesis. 4. Devise an experiment to test the hypothesis. 5. Observe the results of the test. (EXPERIENCE) 6. Draw a conclusion (INDUCTIVE LOGIC) and report your results so others can repeat the test.

18 How to Set up an Experiment
1. Experiments are used to try to determine cause-and-effect. 2. Use your hypothesis to decide what factor you want to test. You deliberately change ONLY that one factor, the independent variable, to see if there is a change in a different factor, the dependent variable. For example, if you want to know the effect of video games on heart rate, you would have your volunteers play video games (independent) to see if their heart rate (dependent) changes.

19 How to Set up an Experiment
3. You should use as many experimental subjects (people, animals, etc.) as possible to make sure the results are not just because of one person’s unusual reaction. 4. To make sure you are not overlooking something, you should also have a control group for which you deliberately do NOT change the independent variable, while watching to see if the dependent variable changes anyway.

20 How to Set up an Experiment
5. Try to keep every other factor constant, except the one you are testing. For instance, make sure everybody got the same amount of sleep, ate and drank the same thing, etc. 6. If possible, you should repeat your experiment several times – especially if you had only a small number of experimental subjects. 7. You should then draw conclusions about whether your hypothesis was confirmed or falsified. Be as logical as possible. 8. Then write a report.

21 How Scientific Knowledge Increases
1. Start with a problem or question. 2. Formulate a hypothesis. 3. Test the hypothesis by experimentation, following the scientific method. 4. If your hypothesis is falsified, you learned something! 5. If your hypothesis seems to be confirmed, report your results (in a peer-reviewed journal) so others can repeat the test and check your work.

22 The Importance of Peer Review
1. An honest scientist would NEVER say something was proven. There could always be something you overlooked! Instead, you state whether your hypothesis was confirmed or falsified. 2. If the hypothesis was confirmed, a scientist pub-lishes a report in a peer-reviewed technical journal – that is, chemists review the work of other chem-ists, astronomers review the work of other astro-nomers, etc. They are looking to see if the experi-menter made a mistake or overlooked something. Many popular magazines are NOT peer-reviewed!

23 The Importance of Peer Review
3. If your work passes peer review at the technical journal, it is published. Other professional scientists may then use your work as a reference to guide them in their own experiments. (You become the authority!)


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