Tuesday, March 26, 2013

Guest speaker: Harry E. Pence, PhD

Dr. Pence is a chemist and State University of New York Distinguished Teaching Professor Emeritus. He presently serves as a Faculty Fellow for Emerging Technologies at the Teaching and Learning with Technology Center at the campus in Oneonta, NY. He has written and presented frequently about emerging learning technologies and has served on several state-wide and national committees that deal with this topic. He is a co-editor, along with Dr. Robert Belford (UALR Chemistry Dept.) of the recently published American Chemical Society book, "Enhancing Learning with Online Resources, Social Networking, and Digital Libraries," and co-authored two chapters in that book.

Wednesday, March 13, 2013

"Scientific Proof" - an Idea Debunked

1. Let us find out what "scientific proof" really means
. . . and what it doesn't

     We can relate this to 
         daily life
         Earth 2100
         or whatever we feel like discussing

A starting point:
    What is the difference between

2. Math:
prove new things
based on
existing knowledge

Mathematical reasoning is:

  • 1+1=2
  • 2+2=4
  • Therefore,
    • 1+1+1+1=4
    • (proof by substitution)

  • All men are mortal
  • Socrates is a man
  • Therefore,
    • Socrates is mortal
    • (proof by "syllogism")

  • Deduction can prove things
  • Mathematics uses deduction
  • Therefore,
    • mathematics can prove things
    • (proof by syllogism again!)

3. Science is different from math!

  • Science is based on:
    • induction
    • (not deduction)
  • All apples that break off the tree,
    • fall down
  • Therefore, if I shake this apple tree,
    • and an apple breaks off,
    • it will fall down
  • Not a proof!
    • Can you think of a counterexample?

  • That which goes up has always come down
  • Therefore, if I throw this up, it will come down
  • Not a proof! Can you think of a counterexample?

4. Science needs more than induction

Humankind has always sought reasons

Scientists call those reasons
"theories" and "hypotheses"

Theories are the BIG ones
  • relativity
  • evolution
  • continental drift/plate tectonics

Hypotheses are the >little< ones
  • If the ground gets waterlogged,
    • water will get into my basement
  • IFSC majors 
    • are more employable 
    • than physics majors

Conclusion. . .
Math proves;
science does not prove!

Science disproves
(by refuting inductive "truths")

Science explains
(using theories)

Science predicts
(because the theories predict)

5. The phrase "scientific proof" makes no sense!
  • Science does not prove things!
  • It explains things and finds evidence
  • If only everyone actually knew that
  • Not just you, but also
    • reporters,
    • spokespeople,
    • politicians
    • the average person
6. Example: Global Warming

7. Example: Various medical advice

8. Example: US legal system

9. Example: More speculative science
                    ("Do toxoplasma germs control humanity?")