WHERE DID PHYSICS COME FROM? Ancient people such as the Greeks were trying to explain the motion of the stars and planets. They made up explanations that made sense to them. However, they had no way to test them. For example, they decided the earth was completely still and everything else in the universe revolved around it in perfect circles.

“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. (Aristotle said it, I believe it, that settles it!)

WHERE DID MODERN PHYSICS COME FROM? 1. The mathematician Nicolas Copernicus showed that mathematically, the motion of the planets was much easier to work out if they revolved around the sun rather than the earth. However, he still had no way to test his ideas. 2. The Danish astronomer Tycho Brahe was fascinated with the heavenly bodies and spent years recording their positions in notebooks. However, he had no idea what to do with his notes.

WHERE DID MODERN PHYSICS COME FROM? 3. Brahe hired an assistant, Johannes Kepler, who analyzed Brahe’s data after his death. 4. Kepler made graphs and discovered that the orbits of the planets were ellipses, not circles. He recognized patterns which led him to formulate three laws of planetary motion by inductive logic. However, there was no way to directly observe so his work was all still theoretical.

WHERE DID MODERN PHYSICS COME FROM? 5. A young Italian scientist named Galileo Galilei (one of the greatest geniuses ever) read about a new invention called a “telescope.” Even though he had never seen one, he made one based on the inventor’s description. For the first time, humans had the ability to carefully observe the heavens. Galileo quickly found that Aristotle was WRONG - that parallax really did exist, so the stars were not all the same distance.

WHERE DID MODERN PHYSICS COME FROM? 6. Galileo could see that the planets went around the sun, but he did not know how to explain their orbits. 7. After Galileo’s death, Isaac Newton built on his work along with the work of Copernicus, Brahe, and Kepler. By inductive logic, he mathematic-ally worked out equations that we call the Law of Gravity and the Laws of Motion. (He had to invent differential calculus to do it!)

This is the heart of the scientific method. Besides working out difficult mathematical concepts, Galileo and Newton insisted on testing ideas by experimentation before accepting them. This is the heart of the scientific method.

THE SCIENTIFIC METHOD 1. You become curious about something and ask a question about it. (E.g. “Does music affect how plants grow?”) 2. Gather information about the subject. (AUTHORITY) 3. Formulate a hypothesis. 4. Devise a way 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.

SO WHERE DID ALL THE EQUATIONS OF PHYSICS COME FROM? 1. Someone became curious about nature and asked a question. 2. They did research to find out what others had done before. 3. They formulated a hypothesis and devised experiments to test it. 4. They observed the results of the tests over and over to make sure they had valid data. 5. They analyzed the data to look for patterns.

SO WHERE DID ALL THE EQUATIONS OF PHYSICS COME FROM? 6. Using inductive logic, the experimenters drew conclusions about the most likely explanation. In many cases, they expressed the conclusions in the form of equations. 7. They reported their results so that others could repeat their experiments and confirm or falsify their conclusions. 8. After many years of testing, the scientific com- munity recognized the conclusions (the equa-tions) as laws of nature. That’s why we use them.

THE SCIENTIFIC METHOD 1. You become curious about something and ask a question about it. (E.g. “Does music affect how plants grow?”) 2. Gather information about the subject. (AUTHORITY) 3. Formulate a hypothesis. 4. Devise a way 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.

WHERE DID ALL THE EQUATIONS OF PHYSICS COME FROM? From the same scientific method you are learning to use! You are following in the footsteps of Galileo, Newton, Faraday, Lenz, Gauss, Leibniz, Lorentz, Rutherford, Bohr, and all the other great scientists of history.