1 UNIT 1: INTRO TO SCIENCE DEFINITION OF SCIENCE MEASUREMENTS MICROSCOPE SCIENTIFIC METHOD

2 What is “Science”? Definition: -knowledge gained through the use of questions and experiments about the physical and living world

3 Branches in Science Astronomy: study of objects and matter outside of earth’s atmosphere Chemistry: study of the composition and properties of matter

4 Branches in Science Meteorology: study of earth’s atmosphere to predict weather Biology: study of living and once living things Botany: study of plants Zoology: study of animals Ecology: study of how living things interact with their environment

5 Why should we study science? prevent diseases to improve existing technology to develop new products like food to maintain and improve the quality of life

6 How do YOU use science in YOUR life? Clothing choice Cooking I-Pods, game stations Care of pets Measurement Weight lifting How far is the walk to Burger King?

7 MEASUREMENTS IN SCIENCE SI: stands for “System International” - measurement system used by scientists around the world - also known as the “metric” system - despite language differences, measurements need to be constant

8 MEASUREMENTS IN SCIENCE MASS: how much matter or “stuff” an object has measured in: kilograms (1 kg) milligrams (1 mg) gram (1 g) measured using: triple beam balance 1 kg = 1000g 1 g= 1000mg

9 Weight vs. Mass WEIGHT: how gravity pulls on an object’s mass Same mass Different weights

10 MEASUREMENTS IN SCIENCE LENGTH: distance between two points (how long something is) measured in:kilometer (1km) meter (1m) centimeter (1cm) millimeter (1mm) measured using: meter stick - the microscope measures in micrometers (really small!) 1 km = 1000m 1m = 100cm 1cm = 10mm

11 Measuring Length in Centimeters Grasshopper is 4cm. Fish is 6cm.

12 MEASUREMENTS IN SCIENCE VOLUME: amount of space an object occupies measured in:liter (1L) milliliter (1mL) measured using: graduated cylinder 1L = 1000mL

13 Measuring Volume in Milliliters 43 mL

14 MEASUREMENTS IN SCIENCE TEMPERATURE: measure of how hot or cold something is (how much energy something has) measured in:Celsius (°C) how measured: thermometer Scientists DO NOT measure in Fahrenheit!

15 Measuring Temperature Use this one!

16 MEASUREMENTS IN SCIENCE pH: measure of how acidic or basic a substance is measured:on a scale 1-14 measured using: litmus paper 1 acidic red basic 14 blue 7 neutral

17 Measuring pH

18 COMPOUND LIGHT MICROSCOPE - Allows you to view specimens at 40x, 100x, or 400x their real size

19 COMPOUND LIGHT MICROSCOPE 7. Eyepiece 1. Body Tube 2. Nosepiece 3. Objective Lens 8. Arm 10. Coarse Adjustment 11. Fine Adjustment 4. Stage 12. Base 6. Light Source 9. Stage Clips 5. Diaphragm

20 Total Magnification Eyepiece x scanning = total magnification (10x)(4x) = 40x Eyepiece x low power = total magnification (10x)(10x) = 100x Eyepiece x high power = total magnification (10x)(40x) = 400x

21 Effects on Image Image is inverted (upside and backwards) Normal viewMicroscope view

22 Depth of Field Organisms are three dimensional (not flat) You can only look at one layer of an organism at a time Use the fine adjustment knob to look at the different layers of an object.

23 Resolution of Image Resolution: the ability to tell the difference between two points that are very close together

24 Effects of Staining Why do we apply stains to microscope images? To enhance details of the object Ex. Methylene blue, iodine No stainStained

25 Field of View When you look in the microscope, all that you see is called the FIELD OF VIEW As the magnification gets larger, the field of view gets smaller The image is “zoomed in” on which means you can’t see all the image at once

26 Field of View continued… Larger magnification but you see less of the object Smaller magnification but you see more of the object

27 Estimating Diameter of the Field of View

28 Measurement Under the Microscope Microscope images are measured in MICROMETERS! 1mm = 1000 um

29 Microscope use in Science Microscopes are a tool to solve many scientific problems! How do scientists solve these many problems and questions? The Scientific Method!

30 Scientific Method Definition: -the way scientists solve problems using 5-6 steps More common than you think; in fact, you use it every day!

31 SCIENTIFIC METHOD 1.State/recognize the problem 2.Make a hypothesis (educated guess) 3.Conduct an experiment 4.Make observations (Record data; graphs) 5.State a conclusion 6.Repeat How long does it take to walk 50 m? It will take 2 minutes. Walk 50 m and time it. Record the time it took to walk 50 m. It actually took 3 minutes to walk 50 m. Do it again.

32 Setting Up An Experiment To perform an experiment, you need: a control (use as comparison; standard) a variable (what you’re testing) - independent variable (I change it!) - dependent variable (what you measure; depends on the independent variable)

33 Experiment Example 1.Problem: Do radish seeds grow taller in more light? 2. Hypothesis: Radish seeds will grow taller in more light. 3. Experiment: Controls (things that will be the same throughout the experiment) - type of radish seeds - amount of water - type of soil and pot

34 Experiment Example cont… Variables: Independent variable: - - amount of light Dependent variable: - height of plant 4. Make Observations: Create data table using light amounts and plant heights Amount of light Height (cm) 3 hours of light 2 4 hours light 4 5 hours light 6

35 Experiment Example cont… Set up graph if necessary Amount of light (independent variable) Height of plant (dependent variable) Title

36 Experiment Example cont… 5. Conclusion: Plants grow better in more light 6. Repeat: Conduct the experiment again

37 Theory vs. Law Theory A hypothesis about a situation that is supported by repeated experiments Ex. Theory of Evolution Continental Drift (Debatable) Law A theory that never changes; theory that has been tested many times Ex. Gravity (Non-debatable)