Week 4: Complete Chapter 3 The Science of Astronomy How do humans employ scientific thinking? Scientific thinking is based on everyday ideas of observation and trial-and-errorand experiments. But science adds the requirement for an explanation of mechanisms Observation alone is not enough 3.4 The Nature of Science Our goals for learning: How can we distinguish science from nonscience? What is a scientific theory? Caveat We see what we are looking for e.g. Where are your keys when you finally find them? Idealized scientific method Based on proposing and dtesting ti hypotheses hypothesis = educated guess Science rarely proceeds in this idealized way Sometimes we start by just looking then coming up with possible explanations. Sometimes we follow our intuition rather than a particular line of evidence. 1
Hallmarks of Science: #1 Hallmarks of Science: #2 Modern science seeks explanations for observed phenomena that rely solely on natural causes. (A scientific model cannot include divine intervention) Science progresses through the creation and testing of models of nature that explain the observations as simply as possible. (Is Occam s razor our own perfect spheres?) Hallmarks of Science: #3 A scientific model must make testable predictions about natural phenomena that would force us to revise or abandon the model if the predictions do not agree with observations. Scientific theory? The word theory has a different meaning in science than in everyday life. In science, a theory is NOT the same as a hypothesis, rather: A scientific theory must: Explain a wide variety of observations with a few simple principles, AND Must be supported by a large, compelling body of evidence. Must NOT have failed any crucial test of its validity. 3.5 Astrology Our goals for learning: How is astrology different from Astronomy? Does astrology have any scientific validity? How is astrology different from Astronomy? Astronomy is a science focused on learning about how stars, planets, and other celestial objects work. astrology is a search for hidden influences on human lives based on the positions of planets and stars in the sky. 2
Does astrology have any scientific validity? Scientific tests have shown that astrological predictions are no more accurate than we should expect from pure chance. What have we learned? How is astrology different from astronomy? Astronomy is the scientific study of the universe and the celestial objects within it. Astrology assumes that the positions of celestial objects influence human events. Does astrology have any scientific validity? Scientific tests show that the predictions of astrology are no more accurate than pure chance. Science or Technology? Science is the process of inquiry Science seeks to understand HOW nature operates by using observation, reasoning, theory. Science can use technology (better thermometers), but does not require it. Technology is the process of tool-making and invention. Technology performs empirically to reach a goal (e.g. perfect machines). Often, but not always using theory and prediction derived from science. So what were the Greeks? Science use empirical methods? Yes, but only as part of the process. Science uses technology? Yes, but only for testing hypotheses. Are science and technology synonymous? No, technology is an application of science Technology is the practical application of knowledge in an area (e.g. engineering) Science and Objectivity The Uncontrolled Experiment: Typical of journalism (e.g., 40% of children improved ) Which children; over what time; compared to whom? The Controlled Experiment: states how much better (1%, 10%, 200%) than a control. In any set of observations, the dependent variable will change in response to the independent or manipulated variable (e.g., growth of corn in soil receiving different levels of fertilizer). Growth of corn is dependent upon the level of fertilizer applied Failing to isolate variables for cause and effect is the single biggest difference between Science and Pseudoscience. Science and Pseudoscience Pseudoscience: discarded scientific ideas, unfounded ideas about the world also called fringe science. Cannot be tested Often presented with a siege or conspiracy theory mentality Poor or nonexistent use of statistics 3
Characteristics of Pseudoscience Appears to be scientific Often commingled with a political or religious agenda example: example: Nazi theories of blood purity. Makes assertions it is scientific, but rejects rigorous scientific testing Quickly accepted by non-scientists Often represented as the grand solution Fatally flawed in content, method, or both Fails to differentiate between cause and effect Cannot be tested (can t test, can t prove wrong!) The more extraordinary the claim, the more extraordinary the evidence needs to be. Carl Sagan Dinosaurs on Venus Venus is 100% cloud covered. Where do we see lots of clouds? Jungles What lives in jungles? Dinosaurs Observation: Can t see a thing. Conclusion: Dinosaurs on Venus Al & Chuck s Excellent Scientific Adventure Alfred Wallace & Charles Darwin were Naturalists. 19th Century Naturalists amassed huge collections of anything natural. They practiced inductive reasoning by examining the range of variations in these collections. This was their Hypothesis: That variation in plants and animals is a result of random mutations. Independently; they proposed Natural Selection (from mutations) as the driving force of Evolution (1850 s). The Theory of Natural Selection Random Mutations can be good or bad depending on the environment. Stated that nature was implicitly easier for one individual or group over another if there was an inherited trait which made the offspring more successful. There is no explicit force implied. But what made it work? Gregor Mendel demonstrated that inherited traits & mutations were passed from one generation to the next (1860 s). Genetic Mutations may be related to environmental incidents in the life of a single parent. Learned attributes are not passed along! None of this was news to Farmers or Ranchers. It was just BREEDING. 4
And if Humans are animals too... Sir Francis Galton coins the term Eugenics (well-born) born). Advocates controlling the birth- rate of the unfit (1900). T.X. Huxley introduces the term Survival of the Fittest which eventually led to the concept of Social Darwinism. Oneida Communities and controlled breeding of humans becomes widespread in the U.S. Muddy Thinking + PseudoScience = National Socialists use Eugenics arguments to defend racial policies. Nazi s envisioned a Master Race (themselves). 10 million+ Jews, Slavs, & Catholics are executed (to avoid contaminating the Aryan Gene Pool). Dinosaurs on Venus and Aryan Supremacy Original Hypothesis: That variation in plants and animals is a result of random mutations. Social Response: World War II -and- Ethnic Cleansing Chapter 3 Redux Understanding the simple observations of Chapter 2 took humans thousands of years. Achieved that understanding through a rigorous process of scientific inquiry. Science itself is a way of making sense of observations Science, by definition, must be flawed; but it works! Term Exam #1 Chapters 1-3 and notes from Weeks 1-4. 45 objective @ 2 points each and 1 essay (selected from 3 choices) @ 10 points. Particular emphasis on Lunar Phases. Backwards definitions common. Just like real life open book and open notes.but be careful not to trip on this. 5