Phy 101 lecture chapter 1
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The document discusses the scientific method and key concepts in science. It explains that science is a process of asking and answering questions through observation, experimentation, and testing hypotheses rather than just collecting facts. The scientific method involves formulating problems, making observations and conducting experiments, interpreting results, and testing interpretations. Theories are more developed than hypotheses and are based on evidence from well-tested experiments. Scientific knowledge is constantly evolving as new evidence is discovered and previous results are questioned.
Phy 101 lecture chapter 1
- 1. Chapter 1 The Scientific Method The Physical Universe K. B. Krauskopf A. Beiser
- 2. Show Explained The notes on the following slides will give you an idea of the sort of things your tutor may point out to you in an effort to assist you in learning the material
- 3. 1.1 What is Science? Science is a Process asking and answering questions Science is not a collection of facts
- 4. 1.1 Two Kinds of Science Life Science living things Physical Science non-living things
- 5. 1.1 The Scientific Method Four Steps Formulating a problem Observation and experiment Interpretation hypothesis Testing the interpretation
- 7. 1.1 Hypothesis and Theory Hypothesis: an educated guess - that can be tested Theory: the synthesis of a LARGE body of information encompassing well-tested and verified hypotheses from experimental observations
- 8. 1.1 Observation and Experiment Observation can be done without an actual experiment An experiment is a careful observation that may require recording quantitative information about the observed phenomenon. An Experiment is simply manipulating nature and then observing the result
- 9. 1.1 Laws of Nature Represents our current best understanding Subject to change based upon additional observations Apply everywhere in the universe From atoms to galaxies Can be used to predict unknown phenomena Allows us to understand what occurs in places we cannot examine directly
- 10. 1.1 Theories and Models A Law tells us what A Theory tells us why A Theory is more than a hypothesis: Fully developed logical structure Based on well understood general principles A Model is a simplified version of reality e.g. the Earth is a sphere
- 11. 1.2 Why Science is Successful Scientific knowledge is not frozen, we constantly add to it Scientists question previous results Common sense is not a valid argument
- 12. 1.2 Science and Religion Science has been at odds with religious doctrine Galileo was forced under the threat of torture to deny that the earth moves about the sun Creationism vs. evolutionary theory
- 13. 1.11 Neptune cont’d Calculations based on the law of gravity predicted the position of an unknown body. The prediction was tested, resulting in the discovery of Neptune.
- 14. 1.2 Science and Religion Science: observe, record and discover natural phenomena based on experimental evidence acquired by using a rigid scientific method ; skepticism is key Religion: a means of understanding the source, purpose and meaning of our world based on faith ; Many principles are accepted without question
- 15. 1.12 Units A physical measurement consist of a number and a unit or standard quantity. Standard quantities such as the mile are known as units .
- 16. 1.12 Units cont’d The result of every measurement has two parts: the number the units For example: 100 miles, 10 meters, etc The most widely units today are the International Units or SI units.
- 17. 1.12 Base Units SI unit Quantity Name Symbol Time second s Length meter m Mass kilogram kg Amount of substance mole mol Thermodynamic temperature Kelvin K Electric current ampere A Luminous intensity candela cd
- 18. Multiply by 10 or divide by 10 for each place! 1.12 Why Metric? 1298347.2348756 1’s place 10’s place 100’s place 1000’s place 10th’s place 100th’s place
- 19. 1.12 Subdivisions and Multiples of Base Units Prefix Power of 10 Abbreviation Prefix Power of 10 Abbreviation Hecto- 10 2 h Centi- 10 -2 c Kilo- 10 3 k Milli- 10 -3 m Mega- 10 6 M Micro- 10 -6 µ Giga- 10 9 G Nano- 10 -9 n Tera- 10 12 T Pico- 10 -12 p
- 20. 1.12 Units: Examples 1km = 1 kilometer = 10 3 meters = 1000 meters 1 GHz = 1 GigaHertz = 10 9 Hertz = 1000,000,000 Hertz 1mm = 1 millimeter = 10 -3 meters = 0.001 meters 1nsec = 1 nanosec = 10 -9 seconds = 0.000,000,001 seconds
- 21. 1.12 kilometers, meters and centimeters
- 22. 1.12 Conversion Factors 1 meter (m) = 100 cm = 1000 mm = 3.28 ft 1 kilometer (km) = 1,000 m = 0.621 mile 1 mile (mi) = 5280 ft = 1.609 km 1 foot (ft) = 12 in = 0.305 m = 30.5 cm 1 day = 24 hrs = 86,400 s
- 23. Distance: Example 1.1 How long is 878 m in terms of kilometers miles
- 26. 1.12 Significant Figures We can only trust as many output digits as the input variable with the fewest digits: If we have a product of a three and a four digit number our result can only have three significant figures It is okay to use more digits in the intermediate steps and then to round the final result