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!