Chapter 1 Science
Science • - concerned with making sense of the environment and what goes on around you. • Concepts –mental image of tangible (blood, rocks, etc…) or intangible objects (motion, velocity, acceleration, etc…)
Describing Properties of an Object • Properties – characteristics • To describe the properties of an object, we generally use “referents” (describing something by comparing it to a more familiar object. Ex. Her eyes are as blue as the sky. • Ex. of Referents : Blue sky, green grass, lemon yellow
Quantifying Properties • Two major systems of standard units • - English System (pound, ounce, feet, yard) • - Metric System (meter, kilogram, Kelvin) • Measurements used to be based on the human body so standardization was needed. • US signed Treaty of the Meter with 16 other countries
7 SI Standard Units • Length meter (m) • Mass kilogram (kg) • Time second (s) • Electric Current ampere (A) • Temperature Kelvin (K) • Amt. of Substance mole (mol) • Luminous Intensity candela cd
Metric Prefixes • Mega- • Kilo - • Hecto- • Deka- • ---- • Deci- • Centi- • Milli-
Doing the Math… • Using Dimensional Analysis or Ratios and Proportions • Hint: Unwanted units need to cancel out! • You should only be left with the unit that you need. • Note: Meaningful measurements have units!
Density • Density = mass of the substance volume of the substance Mass – is the amount of matter in an object Unit of Mass = gram or kilogram Volume – is the amount of space an object occupies Unit of Volume = Liter, mL or cm3
Scientific Investigation • A scientific investigation needs EVIDENCE. • The Scientific Method is used to conduct a Scientific Investigation.
Steps in the Scientific Method • Observation – beyond the scientists’ control • Developing Explanations of Observations • Hypothesis – an educated guess. What he thinks is going to happen • Experimentation – used to test hypothesis, can be controlled by scientists • Results • Conclusion • Modifications, if necessary new hypothesis?
A Good Experiment must be: • 1. Repeatable • 2. Include measurements with the appropriate units (quantitative) • 3. Specific and limited
Science is therefore: • Gathering and testing information to make sense of what is going on around you. • Purpose of Science: To learn it so you can deduce the relationships that govern it.
Law vs. Theory • Scientific Laws – explanation of natural occurrences and phenomenon that has withstood the test of time; tells you “what” will happen if something is done. • Theory – attempt to explain common phenomena but has not yet withstood the test of time so it can still be changed. • - based on broad, working hypothesis based on extensive, experimental evidence. • - attempts to explain “why” something happens
Science, Nonscience and Pseudoscience • Science – uses reliable experiments - is repeatable and has predictive value - determines cause and effect - can only consider natural explanations of physical phenomena Nonscience – has no predictive value; low degree of cause and effect studies Pseudoscience – false or deceptive science
Misconceptions about Science • 1. Science is about memorization of facts. • 2. Science never knows anything. • 3. Science is all powerful and can solve any problem it is applied to. • 4. Science primary purpose is to make the world a better place to live.
Scientific Method Exercise • Application of Observation, hypothesis, etc… • Exercise 2: Can you solve it? • Exercise 3: Big Game Hunter!