- Scientific Method - Hallmarks of science - Occam's Razor - Scientific theory - Common misconceptions - Astrology vs. Astronomy [SLIDE 1] How do we distinguish science from non-science? Not all science works the same way so it can be difficult to use one method to define science. The scientific method, however, is commonly seen as an ideal implementation of science. This process usually begins with making observations, that lead to questions, and then hypotheses or educated guesses, followed by predictions and then tests to confirm or observe. If the test supports the hypothesis, then you can make additional predictions and test them. If the test does not support the hypothesis, you will need to revise the hypothesis or come up with a new one. In real life, however, science rarely progresses as neatly as idealized in the scientific method. [SLIDE 2] If scientific thinking does not always look like the scientific method, how do we define it? One way is to list the criteria that scientists use when they judge competing models of nature. The hallmarks of science include: * Natural causes - modern science seeks explanations for observed phenomena that rely upon natural causes only. * Models of nature - science progresses through the creation and testing of models of nature that explain these observations. * Testable predictions - a scientific model must make testable predictions about natural phenomena that would force us to abandon or revise the model if the predictions did NOT agree with the observations. Science seeks to explain observed phenomena using testable models of nature that explain the observations as simply as possible. [SLIDE 3] Occam's Razor, named after William of Occam, a medieval scholar, was the idea that scientists would prefer the simpler of two models that agree well with scientific observations. An example of this is the Copernican model versus the Ptolemy model. If Copernicus's model had been evaluated solely on the accuracy of its predictions, it would have had no real advantage over the long-established Ptolemy model. But since it had a simpler explanation for some questions such as apparent retrograde motion, it appealed to enough scientists that it continued to get serious consideration and eventually Kepler was able to make it work. [SLIDE 4] While individual scientists may carry personal biases, the collective action of many scientists should make science objective. Some results could be affected by personal biases, but as other people come along and continue to test the results, they will eventually uncover mistakes. A scientific theory is a simple yet powerful model whose predictions have been borne out of repeated and varied testing. The everyday meaning of "theory" is closer to hypothesis or speculation, but in scientific terminology, a theory is considered practically a fact. While scientific theories can never be proven true beyond all doubt, they are supported by a large, compelling body of evidence. [SLIDE 5] For a long time, ancient people including Greek philosophers believed that the Earth was flat. Around 240 B.C., a Greek scientist named Eratosthenes first measured the Earth's circumference and proved that it was round. It was already common belief that the Earth was spherical by that time, but his findings confirmed it as fact. Another common misconception in more recent years is that you can balance an egg on its end during the spring equinox and that this is the only day in the year that you can do this. This is a myth. The equinox is just a point in time when sunlight strikes both hemispheres equally. It is difficult to see how sunlight could affect an attempt to balance eggs as there is nothing different about Earth's gravity or the Sun's gravity that day. Although it takes a lot of practice to balance an egg, you could try it yourself and you would discover that an egg can be balanced on its end any day of the year. The basic lesson here is that prior to accepting any 'claim,' you can and should demand reasonable proof or an explanation with evidence to back it up! [SLIDE 6] Astrology is the study of human behavior and events based on the movement of the Sun, Moon, and planets. For a long time, astrology and astronomy went hand in hand, but today, they are considered two very different things. Although astrology is still practiced by many people, it is not a science since it cannot be tested or proven. It has also been unable to explain natural phenomena or consistently make future predictions.