Introduction to Science. Section 1: The Nature of Science Section 2: The Way Science Works Section 3: Organizing Data

Transcription

1 Introduction to Science Section 1: The Nature of Science Section 2: The Way Science Works Section 3: Organizing Data

2 Section 1: The Nature of Science Key Terms Science Technology Scientific Law Scientific Theory

3 Section 1: The Nature of Science How does science take place? Scientific Investigation Plan Experiments Make Observations Test Results

4 Section 1: The Nature of Science 1895 Wilhelm Roentgen He found that the rays passed through almost everything, although dense materials absorbed them somewhat He called the new rays X-rays because he did not know what the rays were. X = unknown 1901 won Nobel Prize in physics

5 Section 1: The Nature of Science Different Branches of Science We know how science works, but what is science? There are two main branches of science 1. Social Science - deals with individual and group human behavior 2. Natural Science - deals with nature or how the whole universe works

6 Section 1: The Nature of Science Three branches of Natural Science 1. Biological - living things 2. Physical - matter and energy 3. Earth - Earth

7 Section 1: The Nature of Science Biological or Life Science 1. Botany - plants 2. Zoology - animals 3. Ecology - balance of nature

8 Section 1: The Nature of Science Physical Science 1. Physics - forces and energy 2. Chemistry - matter and its changes Physics and Chemistry depend greatly on Mathematics Earth Science 1. Geology - physical nature and behavior of the Earth 2. Meteorology - atmosphere and weather

9 Section 1: The Nature of Science As science progresses so do the branches of science. Now we have over lapping of the different branches 1. Biochemistry - matter of living things 2. Geophysics - forces that effect the Earth

10 Section 1: The Nature of Science Science and Technology Technology How does science and technology work together? Ex. Someone that wants to find out how a material works is doing science. Another person wants to find a way to use the material most effectively is work with technology. Science and Technology depend on one another.

11 Section 1: The Nature of Science Scientific Laws and Theories Scientific Laws allow predictions to be made about how a system will behave under a wide range of conditions. Does not explain how process take place.

12 Section 1: The Nature of Science Scientific Theories how a natural process works Scientific theories are always being questioned and examined

13 Section 1: The Nature of Science For a scientific theory to be valid it must pass several tests 1. Most explain observations clearly and consistently 2. Experiments must be repeatable 3. Must be able to predict from the theory

14 Section 1: The Nature of Science How can we use mathematics to describe physical events? First we can use a qualitative statement to describe an event using words. However, in science we use mathematical equations which are quantitative statements

15 Section 1: The Nature of Science Quantitative expressions make communication among scientists easier. Mathematics is the language of science and the same everywhere. Theories and Laws are always being tested Why are we always testing theories and laws? Kinetic Theory IN Caloric Theory - OUT

16 Section 1: The Nature of Science Models to represent physical events Scientists use scientific models as a representation of an object or event that can be studied to understand the real object or event. Models represent things that are too big, too small, or too complex to study easily

17 Section 1: The Nature of Science Computers are used as models because. 1. Time Efficient 2. Cost Effective

18 Section 2: The Way Science Works Key Terms Critical Thinking Scientific Method Variable Length Mass Volume Weight

19 Section 2: The Way Science Works Science Skills 1. Identifying Problems 2. Planning Experiment 3. Recording Observations 4. Correctly Reporting Data 5. THINKING CRITICALLY

20 Section 2: The Way Science Works What is Critical Thinking? Asking questions and making observations The Scientific Method The scientific method helps us organize ideas and find and evaluate possible answers. It is a way of thinking critically about a question and testing possible answers

21 Section 2: The Way Science Works There is no single scientific method Hypothesis is a possible answer that you can test in some way. An educated guess

22 Section 2: The Way Science Works How do we test hypotheses? By doing a controlled experiment the variables that can affect the outcome are kept constant or controlled except for one. Why do we only change one variable? Harder to draw conclusion and make observation

23 Section 2: The Way Science Works Conducting Experiments NO EXPERIMENT IS A FAILURE Why are no experiments failures? they may lead to new discoveries or let us revise our hypothesis and test different variables What if experiments allow scientist to see what happens in a certain situation

24 Section 2: The Way Science Works Using Scientific Tools Remember back to science skills Some observations can be made by using our senses. However, other require special tools

25 Section 2: The Way Science Works Using these tools correctly requires skills so observations and data is recorded correctly. Examples of Scientific Tools 1. Telescope 2. Spectroscope 3. Particle Accelerators

26 Section 2: The Way Science Works Units of Measurement Remember that mathematics is the language of science For this reason scientist around the world use the metric system for measurement. This is referred to as the International System of Units (SI).

27 Section 2: The Way Science Works Base units are called derived units * Know the base units and prefixes (pg 16) * King = Kilo Henry = Hecto Died = Deca Monday = Base unit (ex. meter, gram) Drinking = Deci Chocolate = Centi Milk = Milli

28 Section 2: The Way Science Works Prefixes are used for very large and very small numbers. They help us to avoid writing lots of decimals. Prefixes are in multiples of ten. Going to smaller units you multiple Going to larger units you divide

29 Section 2: The Way Science Works Making Measurements Many observations rely on quantitative measurements. They usually answer basic questions such as how much time or how big (grams or volume)

30 Section 2: The Way Science Works Basic measurements 1. Time = seconds 2. Length = meters 3. Mass = grams 4. Volume = cubic meters 5. Weight = Newton

31 Section 2: The Way Science Works What is the difference between Mass and Weight? Mass is the amount of matter in an object and weight is the gravitational force exerted on an object.

32 Section 3: Organizing Data Key Terms Scientific Notation Precision Significant Figures Accuracy

33 Section 3: Organizing Data Organizing Data Why is having organized data important? Helps others to understand or repeat your experiment Presenting Scientific Data With the use of graphs data can be presented for some one else to read.

34 Section 3: Organizing Data Three types of graphs 1. Line Graph 2. Bar Graph 3. Pie Chart/Graph

35 Section 3: Organizing Data 1. Line Graph-Best used for displaying data that changes. Independent Variable - chose when to make measurements Dependent Variable - value depends on what happens

36 Section 3: Organizing Data Line graphs usually have a x and y-axis. The x-axis shows the independent variable and the y-axis shows the dependent variable. What can you tell me from the information in figure 17 (pg 21)?

37 Section 3: Organizing Data 2. Bar Graphs-Best used for comparing similar data for several individual items or events. They often make data clearer on how large or small the differences in individual values are. 3. Pie Charts-Best used when showing parts of a whole (percentages)

38 Section 3: Organizing Data Writing Numbers in Scientific Notation Scientific notation helps scientists write numbers that are very large or very small. This is done by using a simple number multiplied by a power of ten.

39 Very large numbers have a positive power of ten and very small numbers have a negative power of ten. Section 3: Organizing Data Using scientific notation When you multiple two numbers together in scientific notation, you add the powers of ten. When you divided, you subtract the powers of ten.

40 Section 3: Organizing Data Using Significant Figures When using a tape measure, what gives you more precision? Having smaller divisions

41 Section 3: Organizing Data A tape measure that measures to the nearest hundredths is more precise than one that measures to the nearest tenths. To show the precision of a measured quantity, scientist use significant figures (Sig. Figs.)

42 Section 3: Organizing Data Rules for Determining the Number of Sig. Figs. in a Measurement (pg 834) 1. All nonzero digits are significant. (1246 = four sig. figs.) 2. Any zero between significant digits are also significant.(1206 = four sig. figs.) 3. If the value does not contain a decimal point, any zero to the right of a nonzero digit are not significant. (1200 = two sig. figs.)

43 Section 3: Organizing Data 4. Any zero to the right of a significant digit and to the left of a decimal point are significant. ( = four sig. figs.) 5. If a value has no significant digits to the left of a decimal point, any zero to the right of the decimal, and to the left of a significant digit, are not significant. (.0012 = two sig. figs.) 6. If a measurement is reported that ends with zeros to the right of the decimal point, those zeros are significant. (.1200 =

44 Section 3: Organizing Data Adding or Subtracting Answers can only have as many decimal positions as the value with the least number of decimal places.

45 Section 3: Organizing Data Multiplying or Dividing Answers can only have as many sig. figs. as the value with the least amount of sig. figs. Significant figures help us with precision

46 Section 3: Organizing Data What is the difference between precision and accuracy? Precision - exactness of an answer

47 Section 3: Organizing Data Accuracy - description of how close a measurement is to the true value of the quantity measured A measurement is only as accurate as the tool used to make the measurement.