Chapter 1 - About Science Scientific Measurements Scientific Method Scientific Attitude Science, Art, and Religion Science and Technology Physics, THE Basic Science In Perspective Physics 1100 – Spring 2012

Scientific Measurements Hallmark of a good science How far back has man been making “scientific measurements” Seasons Sizes Distances Measurements and observations not only allow us to describe, but to predict! How high will a ball bounce? What are the rules of the “game” Physics 1100 – Spring 2012

An Historical Example - The size of the Earth Eratosthenes ~235 BC (Egypt - noon June 22) 1/50 of a circle & distance is 800Km Physics 1100 – Spring 2012

The size of the Moon Aristarchus ~ 240 BC 12,740/3.5 = 3,640Km Physics 1100 – Spring 2012

Distance to the Moon (the early Greeks knew this!) Physics 1100 – Spring 2012

What Is Science? Which of the following best describes “science”? A compendium of answers A set of rules about the natural world A methodology Exploration, curiosity; a compendium of questions Observation, experimentation Science has bits of all these (esp. last four) Physics 1100 – Spring 2012

Science is Verifiable by Others Embrace Ideas that can be tested Science tends to be self-correcting Hypothesis, Theory, Laws, Fact, Testable Predictions “No number of experiments can prove me right; a single experiment can prove me wrong” – A. Einstein Physics 1100 – Spring 2012

Science = A Process for Change! Discovery Experiment/Observation Hypothesis Prediction Test Theory An ongoing cycle – the “scientific method” Physics 1100 – Spring 2012

What is “Physics” An attempt to rationalize the observed Universe in terms of irreducible basic constituents, interacting via basic forces. Always look for the simplest explanation An evolving set of (sometimes contradictory!) organizing principles, theories, that are subjected to experimental tests. This has been going on for a long time.... with considerable success Physics 1100 – Spring 2012

Physicists View of the World of Science Engineering Biology Geology Chemistry Astronomy Physics Physical Reality Our Universe Abstraction Mathematics Logic, Numbers, Operators Physics 1100 – Spring 2012

Attempt to find unifying principles and properties e.g., gravitation: Physics Goals Attempt to find unifying principles and properties e.g., gravitation: Kepler’s laws of planetary motion Falling apples Universal Gravitation “Unification” of forces Physics 1100 – Spring 2012

All the stuff you see around you Chemical compounds Elements (Atoms) Physics Goals All the stuff you see around you Chemical compounds Elements (Atoms) e,n,p Many thousands Many hundreds Tens 3 An ongoing attempt to deduce the basic building blocks Superstrings? Physics 1100 – Spring 2012

As our understanding grows, theories are supplanted (or subsumed) An Evolving World View As our understanding grows, theories are supplanted (or subsumed) Kepler’s laws of planetary motion Falling apples Universal Gravitation General Relativity Physics 1100 – Spring 2012

Clicker Questions 1) The scientific method is most effective in A) gaining, organizing, and applying new knowledge. B) making theories. C) performing experiments. D) discovering new things. E) making hypotheses. 2) In science, an educated guess is a A) theory. B) hypothesis. C) both of these Physics 1100 – Spring 2012

Clicker Questions 3) In science, facts A) mean very little. B) are absolute. C) may change. D) are more important than theories. 4) The synthesis of a large collection of information that contains well-tested and verified hypotheses about certain aspects of the world is known as a scientific A) hypothesis. B) law or principle. C) theory. D) fact. E) none of these Physics 1100 – Spring 2012

Clicker Questions 5) Which of the following is a scientific statement? A) The moon is made of green cheese. B) There are parts of the universe that will never be found by man. C) Matter is filled with undetectable particles. D) There are things we will never know about. E) none of these 6) The statement, "There are regions beneath the Earth's crust that will always be beyond the reach of scientific investigation," is a A) fact. B) scientific statement. C) speculation. D) theory. E) hypothesis. Physics 1100 – Spring 2012