1-1: What is Physics? Objectives: Identify activities and fields that involve the major areas within physics Describe the process of the scientific method Describe the role of models and diagrams in physics Standards: P1.1, P1.2 Assessments: Read the section Define all vocabulary for this section

We can ’ t control Earth ’ s motion, but we have learned the rules by which it moves. The study of nature ’ s rules is what this book is about. Understanding these rules adds richness to the way we see our world.

What is Physics? Physics is the study of the physical world. You are using physics everyday of your life, you may not realize it but most of the things we do everyday involve physics. Anything that deals with temperature, size, motion, position, shape, or color involves physics. Physics is about the nature of basic things such as motion, forces, energy, matter, heat, sound, light, and the composition of atoms.

The study of science branches into the study of living things and nonliving things. The life sciences include biology, zoology, and botany. The physical sciences include geology, astronomy, chemistry, and physics. 1.1 The Basic Science — Physics

You can understand other sciences much better if you first understand physics. Physics is the most basic of all the sciences. Chemistry is about how matter is put together. Biology is still more complex and involves matter that is alive. 1.1 The Basic Science — Physics

Areas within Physics Mechanics – Motion and its causes Falling objects, friction, weight, spinning objects Thermodynamics – Heat and temperature Melting and freezing processes, engines, refrigerators Vibrations and wave phenomena – Specific types of repetitive motions Springs, pendulums, sound Optics – Light Mirrors, lenses, color, astronomy Electromagnetism – Electricity, magnetism, and light Electrical charge, circuitry, permanent magnets, electromagnets Relativity – Particles moving at any speed, including very high speeds Particle collisions, particle accelerators, nuclear energy Quantum mechanics – Behavior of submicroscopic particles The atom and its parts

The Scientific Method In science we need to question things around us! 1.Make observations. 2.Formulate and objectively test hypothesis by experiments. 3.Interpret results and revise the hypothesis if necessary. 4.State conclusions in a form that can be evaluated by others.

Scientific methods generally include some, if not all, of the following: 1.Recognize a problem. 2.Make an educated guess—a hypothesis—about the answer. 3.Predict the consequences of the hypothesis. 4.Perform experiments to test predictions. 5.Formulate the simplest general rule that organizes the main ingredients: hypothesis, prediction, and experimental outcome. 1.1 Scientific Methods

Models and the scientific method Models are ways to show the structure or workings of an object, system, or concept. Use models that describe only part of reality – Isolate what you need to know. – Draw a diagram that includes only the relevant information – Disregard irrelevant information – Simplify the surroundings Wind resistance, water resistance, etc…

Scientific methods are extremely effective in gaining, organizing, and applying new knowledge. The scientific method is often credited to the Italian physicist Galileo Galilei (a.) and the English philosopher Francis Bacon (b.). 1.1 Scientific Methods

Models and the scientific method Models can help build hypotheses – A hypothesis is a reasonable explanation for an observation. – Models can be used to show how a hypothesis can be tested.

Models and the scientific method Models help guide experimental design – Models can be used to actually do the experiment or demonstration. – A key part of using models and doing experiments is to have a controlled experiment. A controlled experiment is an experiment involving manipulation on a single variable or factor.

Models and the scientific method Using models will help to prove a hypothesis. Either true or false. Some models may not end up in the same results as others. In this case the hypothesis needs to be tested many more times. A conclusion is valid only if it can be verified by other people

Although the scientific method is popular, it is not the universal key to discoveries and advances in science. Trial and error, experimentation without guessing, and accidental discovery account for much of the progress in science. The success of science has more to do with an attitude of inquiry, experimentation, and humility than with a particular method. 1.1 Scientific Methods

In science, a fact is a close agreement by competent observers who make a series of observations of the same phenomenon. A scientific hypothesis is an educated guess that is not fully accepted until demonstrated by experiment. When hypotheses about the relationship among natural quantities are tested over and over again and not contradicted, they may become laws or principles. 1.1 The Scientific Attitude

Scientists must accept their findings even when they would like them to be different. They must distinguish between what they see and what they wish to see. 1.1 The Scientific Attitude

Scientific Theories A scientific theory is a synthesis of a large body of information that encompasses well-tested and verified hypotheses about certain aspects of the natural world. 1.1 The Scientific Attitude

The theories of science evolve as they go through stages of redefinition and refinement. The refinement of theories is a strength of science, not a weakness. More important than defending beliefs is improving upon them. Better hypotheses are made by those who are honest in the face of experimental evidence. 1.1 The Scientific Attitude