How science changes
Upcoming SlideShare
Loading in...5

How science changes






Total Views
Views on SlideShare
Embed Views



0 Embeds 0

No embeds



Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

How science changes How science changes Presentation Transcript

  • How Science Changes
    Leslie Prohaska
    Florida State University
    Field Lab Internship
    Dr. Alejandro Gallard
    October 19, 2009
  • The story of Pangea
    Remember how the theory of plate tectonics developed
    Alfred Wegener proposed his idea of continental drift in his 1915 book, The Origin of Continents and Oceans
    His evidence included fossils of the same lizard and same plant being found on the eastern side of South America and western side of Africa
    This was not enough though…
  • More evidence needed
    When technology improved after World War II, scientists were able to map the floor of the ocean
    Magnetic stripes were found on the sea floor which proved that the sea floor was spreading
    The theory of plate tectonics was finally accepted in the 1960’s because of this evidence
  • This is how science works
    • Scientists continue to experiment, to make observations, take data, and collect evidence
    • As technology improves, there are new ways to experiment and to make these observations
    • If this new information does not fit with the old explanations or, then scientists will make new theories to explain their findings
    • Yes, scientists can change their minds!
  • Science is about improving our understanding
    • The history of science reveals both evolutionary and revolutionary changes. With new evidence and interpretation, old ideas are replaced or supplemented by newer ones. (NSTA Board of Directors, 2000)
    • Progress in science consists of the development of better explanations for the causes of natural phenomena. (Teaching about Evolution and the Nature of Science, 1998, p.42)
    • Explanations that we discuss today may continue to change.
  • Other examples…of the nature of science…that we have Discussedbefore
  • The Atomic Theory
    • Democritus, ‘atomos’
    • Dalton, 1808, all matter is made of atoms
    • JJ Thomson, 1897, plum pudding model
    • Rutherford, 1909, gold foil experiment, most of the atom is open, empty space
    • Bohr, 1913, orbits and energy levels
    • Modern atomic model, wave mechanics model, 1926
  • The Cell Theory
    • Robert Hooke, 1665, first saw cells in microscope and thought they looked like little rooms he called cells
    • Matthias Schleiden –1837, all plants are composed of cells
    • Theodore Schwann – 1839, all animals are composed of cells
    • Modern Cell Theory – 1858, 1) cells are the basic unit of life, 2) all organisms are composed of one or more cells, 3) all cells arise from preexisting cells
  • History of classification
    • Aristotle – 350 B.C. 2 large groups, plants and animals
    • Carolus Linnaeus – 1753, kept two kingdoms but broke them into smaller groups and had everyone use Latin
    • Five kingdom system, 1959, Animal, Plant, Fungi, Protists, Moneran, Whittaker
    • Six kingdom system proposed/Three domains???? Still not resolved
  • Things continue to change
    • As scientific knowledge evolves, major disagreements are eventually resolved… (National Science Education Standards, 1996, p. 171)
    • This is part of scientific inquiry
  • References
    American Association for the Advancement of Science. (1990). Chapter 1: The Nature of Science. Retrieved October 17, 2009, from
    National Science Education Standards observe, interact, change, learn. (1996). Washington, DC: National Academy Press.
    NSTA Board of Directors. (2000, July). Nature of Science Position Statement - NSTA Position Statements. Retrieved October 17, 2009, from
    Teaching about evolution and the nature of science. (1998). Washington, DC: National Academy Press.