The Nature of Science Truth Proof Belief Evidence Debate Consensus

• The Nature of Science

• Truth Proof
• Belief Evidence
• Debate Consensus

• Human activities are the major cause of global warming.

• I agree
• I think that humans have a small role in global warming
• I disagree that human activities that any role in global warming
• I am not well-informed enough to have an opinion either way

• Which of the following is true of Darwin’s Theory of Evolution by Natural Selection?

• A small but vocal minority of scientists believe that the theory of evolution is true
• Scientific opinion is about evenly split as to whether evolution really explains the diversity of life on Earth.
• Scientific opinion runs about 90% in favor of the theory of evolution and about 10% opposed.
• While widely accepted by most scientists, there would still be “reasonable doubt” about whether evolution is true -- Judicial proof is much harder to achieve than scientific proof.
• None of the above: evolution is the only plausible explanation for the diversity of life on earth.

• The scientific method:

• The scientific method
• Based on proposing and testing hypotheses
• hypothesis = educated guess

• “I believe…”

• Based on what?

• Evidence.

• Baloney detection kit

• How reliable is the source of the claim?
• Does the source make similar claims?
• Have the claims been verified by somebody else?
• Does this fit with the way the world works?
• Has anyone tried to disprove the claim?
• Where does the preponderance of evidence point?
• Is the claimant playing by the rules of science?
• Is the claimant providing positive evidence?
• Does the new theory account for as many phenomena as the old theory?
• Are personal beliefs driving the claim?

• Baloney detection kit

• Science is NOT a democracy!

• Although the media seem to think it is…

• 2-3 other scientists, not involved in the study, read your paper and determine whether it has any obvious errors.

• Peer Review:

• After publication in the scientific literature:

• The rest of the scientific community now has the opportunity to try to reproduce your results.
• Open debate in the scientific community
• All scientists get a chance to review it!

• If the idea survives open debate in the scientific literature…

• Scientific
• consensus

• “Consensus” does not mean that 100% of scientists will agree with the idea, only that the vast majority do.

• Example:
• “human activities are the major cause of global warming”
• 400 scientists disagree. HOWEVER…
• Only about 10 of them have expertise in climate science and closely-related fields. The other 3000 climate scientists agree with the statement.

• * National Oceanic and Atmospheric Administration
• * Environmental Protection Agency
• * NASA's Goddard Institute of Space Studies
• * American Geophysical Union
• * American Institute of Physics
• * National Center for Atmospheric Research
• * American Meteorological Society
• * The Royal Society of the UK
• * Canadian Meteorological and Oceanographic Society
• * American Association for the Advancement of Science
• # Academia Brasiliera de Ciencias (Brazil)
• # Royal Society of Canada
• # Chinese Academy of Sciences
• # Academie des Sciences (France)
• # Deutsche Akademie der Naturforscher Leopoldina (Germany)
• # Indian National Science Academy
• # Accademia dei Lincei (Italy)
• # Science Council of Japan
• # Russian Academy of Sciences
• # Royal Society (United Kingdom)
• # National Academy of Sciences (USA)
• * Australian Academy of Sciences
• * Royal Flemish Academy of Belgium for Sciences and the Arts
• * Caribbean Academy of Sciences
• * Indonesian Academy of Sciences
• * Royal Irish Academy
• * Academy of Sciences Malaysia
• * Academy Council of the Royal Society of New Zealand
• * Royal Swedish Academy of Sciences

• Human activities are the major cause of global warming.

• I agree
• I think that humans have a small role in global warming
• I disagree that human activities that any role in global warming
• I am not well-informed enough to have an opinion either way