Thinking like a scientist

1. Thinking like a scientist Galileo Gallilei and his telescope

2. The goal of science • To investigate and understand the world around us • To explain events in the natural world • To make useful predictions AIDS virus Orion nebula

3. Tools of a scientist • Observation- gathering information in an orderly way • Skepticism- asking questions and needing proof • Logic- interpreting data analytically • Collaboration- willingness to share ideas and work with others

5. Spontaneous generation • A recipe for bees • Kill a bull in winter • Build a shed • Place the dead bull • on branches inside the • Shed • 4.Wait for summer. The • Decaying body of the bull • Will produce bees • People believed that life could somehow arise from non-living things From the Romans, circa 8 CE

6. Redi and the maggots • People thought that maggots (larval flies) arose from meat • In 1668, F. Redi did an experiment to test this idea

7. Redi’s experiment • 3 sets of jars: one left open, one sealed with a lid, one covered with cloth

8. Looking at variables • Controlled variables: both jars have meat, location and temp the same • Manipulated variable: gauze covering keeps flies off the meat • Responding variable: whether maggots appear

9. Spallanzani’s Experiment : microbes in gravy In the 1700s, micro- scopes reveal the existence of cellular life Gravy is teeming with microorganisms. Flask is open. Gravy is boiled. Gravy is free of microorganisms. Flask is sealed. Gravy is boiled and sealed

10. Pasteur’s experiment Broth is boiled. Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms. In 1864, spontaneous generation was finally disproved by this experiment

11. Knowledge in science is built upon the work of others. • Experiments must be repeatable • Conclusions are made based on fact and logic, not popular belief. • Science knowledge is always changing Superconductors at low temperatures