Scientific Method El Método Científico Estudio del Capítulo 1 Págs. 1-18

Pasos

Hipótesis y Teorías Hipótesis verificadas repetidamente e indefinidamente Hipótesis verificadas repetidamente e indefinidamente

Teoría refutada Teoría de la generación Espontánea Teoría de la generación Espontánea De materia orgánica pueden surgir espontáneamente organismos De materia orgánica pueden surgir espontáneamente organismos Surge controversia entre Defensores y Opositores Surge controversia entre Defensores y Opositores Ver experimento de las moscas de F. Redi Ver experimento de las moscas de F. Redi

Application to Everyday Problems Assume you are late for an appointment and hurriedly try to start your car Assume you are late for an appointment and hurriedly try to start your car 1. Observation: The car won’t start

Descubrimiento de la Penicilina 1929: Alexander Fleming 1929: Alexander Fleming Cultivaba bacterias Cultivaba bacterias Contaminación con el hongo Penicillium notatum Contaminación con el hongo Penicillium notatum Aplicó el método científico: Observación, hipótesis Aplicó el método científico: Observación, hipótesis Descubrimiento de sustancia inhibitoria de crecimiento de bacterias. Descubrimiento de sustancia inhibitoria de crecimiento de bacterias.

Science Is a Human Endeavor 1. In the 1920s, bacteriologist Alexander Fleming grew bacteria in cultures 2. One of the bacterial cultures became contaminated with a mold 3. Fleming nearly destroyed the culture when he noticed the mold (Penicillium) inhibited bacterial growth in the culture

Teorías Hipótesis verificadas repetidamente. Hipótesis verificadas repetidamente. Se pueden descartar con el paso del tiempo a la luz del nuevo conocimiento. Se pueden descartar con el paso del tiempo a la luz del nuevo conocimiento. Ej. La abiogénesis Ej. La abiogénesis

Science is a Human Endeavor 4. Fleming hypothesized that the mold produced an antibacterial substance 5. Further tests using broth from pure Penicillium cultures lead to the discovery of the first antibiotic, penicillin

Science Is Based on Reasoning Inductive Reasoning Inductive Reasoning Used in the development of scientific theories Used in the development of scientific theories A generalization is created from many observations A generalization is created from many observations e.g., the cell theory (all living things are made of one or more cells) arises from many observations that all indicate a cellular basis for life e.g., the cell theory (all living things are made of one or more cells) arises from many observations that all indicate a cellular basis for life

The Scientific Method Scientific experimentation tests the assertion that a single variable causes a particular observation Scientific experimentation tests the assertion that a single variable causes a particular observation The experiment must rule out the influence of other possible variables on the recorded observations The experiment must rule out the influence of other possible variables on the recorded observations

The Scientific Method Controls are incorporated into experiments Controls are incorporated into experiments Controls keep untested variables constant Controls keep untested variables constant Scientific method is illustrated by Francesco Redi’s experiment Scientific method is illustrated by Francesco Redi’s experiment