Probabilities, the Scientific Method and Religious Faith

1. Probabilities, the Scientific Method and Religious Faith Don E. Bray College Station, Texas 979-492-9534 debray1@mac.com Presentation at Christ United Methodist Church, 02/03/10

2. The Scientific Method The term scientific method is used to describe controlled experiments where the outcomes of several repetitions may produce different results. The differences in outcomes may be attributed to experimental error, or to erroneous assumptions. The mathematical error shows the degree of agreement or disagreement with the initial assumption. Adapted from: http://www.britannica.com/eb/article-60609/principles-of-physical-science

3. Definitions Hypothesis – idea of broad scope, conceived by the human imagination, that encompasses a family of (experiential) laws regarding regularities existing in objects and events, both observed and posited. Theory -is a structure suggested by these laws and is devised to explain them in a scientifically rational manner. Fact - a thing that is indisputibly the case. Source – Encyclopedia Britannica Onlire 2010

4. Short Definitions • Hypothesis – an idea……... • Theory -is a suggested structure….. • Fact - the Sun is going to rise

5. The Role of Experiments • Experiments are often performed to test hypotheses in order to develop theories • To test a theory, we need to select the likely factors and anticipate the outcomes • How well our predicted outcomes are confirmed by experiment indicates the validity of our theory.

6. Probability of a Heads in a coin flip Probability of a tails would be the same.

7. Probability of getting a six from one roll of a six sided die

8. Likelihoods or Probabilities • Expresses likelihood of an event occurring. • A baseball hitter batting 0.333 will be expected to get a hit once for every three times at bat. • A baseball hitter batting 0.200 will be expected to get a hit once for every five times at bat. • These batting averages are based on the data set which is the previous batting record of the individual.

9. Using Probabilities • The probability is an expectation, not an assured result. • The baseball manager cannot expect that a batter hitting 300 will always get a hit. He may go hitless for ten at bats and then get four or five straight hits. • A probability = 1 is assured, will always occur. • A probability = 0 will never occur.

10. Drawing Marbles from a Bag

12. Drawing Marbles from a Bag • TRUTH is the number of Solid marbles in the bag • Guess the TRUTH. • Draw five marbles at a time and record Clear and Solid marbles. • Plot the distribution of Solid marbles after each draw. • Compare ESTIMATED TRUTH with the REAL TRUTH.

14. Risk of Wrong Conclusion From too Small of a Data Set • Often, we do not know the truth, we must speculate based on available data. • Three groups were each given a bag with different distribution of solid and clear marbles (Truth). • The next slide shows the results of their draws. • As the number of draws increases, note how the perceived difference between the three groups changes.

16. Views from too small of a data set! • Neal Bortz, 03/20/08 on his broadcast cited 5 year ocean temperature which showed no change and chortled that evidence for global warming was nowhere to be seen.

17. Old Farmer’s Almanac

18. Direct Plot from NASA Goddard

19. Effect of Sample Period on Perceived Slope (From Lord Monckton 2009) 14 year 10 year 2 year 6 year

20. Fact-Shipping lanes are opening over the Arctic Circle!

21. What does this have to do with your religious faith? • You might need to change some of your beliefs, given new scientific findings. • As did John Wesley ……………..