Thinking like a scientist Galileo Gallilei and his telescope

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

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

Spontaneous generation People believed that life could somehow arise from non-living things People believed that life could somehow arise from non-living things A recipe for bees 1.Kill a bull in winter 2.Build a shed 3.Place the dead bull on branches inside the Shed 4.Wait for summer. The Decaying body of the bull Will produce bees From the Romans, circa 8 CE

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

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

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

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

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

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