Presentation on theme: "The Scientific Method By Joseph A. Castellano, Ph.D."— Presentation transcript:
1The Scientific Method By Joseph A. Castellano, Ph.D. RESEED Silicon Valley
2What is Science?Science is the study of natural processes called phenomena that we can see, hear or touch.Science is very broad and investigates living things such as animals and plants as well as non-living matter and energy.In this class, we study Physical Science, which includes chemistry, physics, astronomy, and other related topics such as density.
3How Scientists WorkThe two key questions that all scientists ask are WHY and HOW.Scientists raise questions about the world around them and seek answers by making careful observations. This often leads to an initial theory or hypothesis.
4The Work of ScientistsScientists conduct tests called experiments to discover why and how a process works to test the initial hypothesis.All experiments, measurements, and observations are carefully recorded in a notebook so that experimental results can be repeated and verified.
5The Scientific MethodScientists use experimental results to confirm the theory or to create a new or modified theory of why and how the process works.The theory is tested by how well it fits with other theories and predicts new findings.Scientist then publish the results in a scientific journal so other scientists can repeat and verify the results to test the theory further.After many years of testing a theory, it may become so well accepted that it is recognized as a Law of Nature.
6The Scientific Method Idea (Hypothesis) Observations Measurements Lab ExperimentsObservationsRecord Results – Formulate Theory
7The Scientific Method Confirm and Test Theory Publish Findings Scientists Repeat & Verify ResultsTheory Becomes a Law of NatureNew Products Developed
8Scientific Measurements Scientists use the metric system in their experimentsConcept of LengthThe standard unit of length is the meter, identified as mAnother common unit of length is the centimeter or cm1 centimeter (cm) = 1/100 meter (m) = .01 mor1 meter (m) = 100 centimeters (cm) = 100 cm
9Scientific Measurements Standard Metric Units of Length1,000 m = 1 kilometer (km) ROADS100 cm = 1 m METRIC RULER10 millimeters (mm) = 1 cm METRIC RULER1,000 microns (μ) = 1 mm MICROSCOPE
10Scientific Measurements Concept of MassThe metric unit of mass is the kilogram or kg1 kilogram (kg) = 1/1000 gram (g) = .001 gor1 kg = 1,000 gConcept of TimeThe standard unit of time is the second or s
11Scientific Measurements Standard Metric Units of Mass1,000 g = 1 kg1,000 milligrams (mg) = 1 g1,000 micrograms (μg) = 1 mg1,000,000 micrograms (μg) = 1 gPERSON (50 – 60 kg)EGG (45 – 50 g)GRAIN OF SAND (12 μg)
12Scientific Measurements: Concept of TemperatureThe standard international unit for temperature is degrees Celsius, designated as CAnother unit of temperature often used by scientists is Kelvin, designated as K. K = CDegrees Fahrenheit ( F) is mostly used in the United States by the general public.The conversion from F to C is: C = 5/9 ( F – 32).ooooooo
13Scientific Measurements Accuracy & Precision (Reproducibility)AccuracyHow much uncertainty does your measurement have?Half of the smallest interval marked on the toolSee your metric ruler: if the true value is centimeters and the metric ruler has millimeter marks, then you can be accurate to:Uncertainty is not about place value, so it is wrong to say mm because you can’t read 1/100 mm on the tool!cm or mm
14Scientific Measurements Accuracy & Precision (Reproducibility)PrecisionDo you get the same number over and over?You measure the mass of a piece of steel three times and get the following results:50.2 g g gThe average is: (50.2 g g g) / 3 = 50.3 gso the measurements are precise to gNote the unit g after each numberThere are no naked numbers in science!
15Scientific Measurements Accuracy & Precision (Reproducibility)There is no such thing as a perfectmeasurement so it is important to know boththe accuracy (uncertainty) and precision(reproducibility) of the measurement.
16Scientific Calculations Balancing of UnitsWhen making calculations always make sure the units balance.Example: A runner reaches a speed of10 meters/second, 20 seconds after he starts.How far does he travel?D (distance) = V (velocity) x t (time)D = 10 m x 20 s = 200 msXXThe answer is 200 meters
17The Importance of Science Science provides the means to improve the way of life for current and future generations of people. Scientists:Develop new instruments and surgical techniques to identify and cure diseases.Create new products that improve communications, transportation, and entertainment.Ensure the cleanliness and safety of the environment.Discover new drugs that improve and extend health.
18The Importance of Science Science is at work in everyday life.An automobile’s operation involves many interrelated scientific principles including electricity, mechanics, chemistry, and physics.The calculator you use in class employs a combination of chemistry, physics, and electronic engineering.The computers in our classroom use complex mathematical principles, wireless communication technology, electronics, mechanics, chemicals, and more.Understanding science will help in your future endeavors, regardless of what they might be.