Date post: | 16-Jan-2016 |
Category: |
Documents |
Upload: | claire-martin |
View: | 219 times |
Download: | 0 times |
Ms. JohnsonFoundations
CHAPTER 17: SCIENTIFIC DISCOVERY
Science is the search for the truth about the universe. The processes of science include questioning, exploring, experimenting, observing, measuring, concluding, and communicating. Science also includes a body of knowledge consisting of facts, theories, principles, laws, and so on.
The scientifi c method is a procedure by which scientifi c discovery can be accomplished. However, scientifi c discovery is not a single process; it can be accomplished in many diff erent ways.
Factors that infl uence scientifi c discovery may be social, economical, and technological.
The ways scientifi c discovery occurs vary greatly in time and the number of scientists contributing to the discovery. It often takes many years and many individuals to arrive at the truth about some aspect of the universe.
OBJECTIVES
ScienceScientific methodHypothesisTheory
VOCABULARY
Science: the search for the truth about the universe and a body of knowledge consisting of facts, laws, principles, and theories. It is a process by which information about the
universe is gathered and organized into bodies of knowledge such as biology, physics, chemistry, geology, and astronomy.
Science seeks answers about the world around us.
Science also involves exploring, experimenting, observing, measuring, concluding, and communicating.
SCIENCE DEFINED
Scientific method: a process that helps scientists make discoveries.State the problemCollect informationForm a hypothesisTest your hypothesis (experiment)Record observationsCheck results (or re-test)
If the results are incorrect, form a new hypothesis and test it
Draw conclusionsCommunicate results
SCIENTIFIC METHOD
Hypothesis: plausible guess based on the known facts Proposed to answer the questions Followed by experimentation to test the hypothesis
If all evidence gathered supports the hypothesis and appears to lead to new truths about the universe, a theory can be presented.
A theory can raise new questions that will lead to new hypotheses, new experiments, and new studies.
SCIENTIFIC METHOD
A scientific experiment includes a control group and an experimental group. Control: conditions
remain the same or as close to normal so the experimental group can be compared to it
Experimental: the group that is manipulated in an experiment
SCIENTIFIC METHOD
Many of the great discoveries in science have come about over a span of many years, with contributions made by many people.1. Plate Tectonics2. Heliocentric Solar System3. Germ Theory4. Atomic Theory
EXAMPLES OF MAJOR SCIENTIFIC DISCOVERIES
Two discovery questions: How did the
continents get to their present shapes and positions?
What process could cause the continents to shift on Earth’s surface?
1912 Alfred Wegener proposed
continents were moving due to the shapes of the continents and matching features of rocks and fossils had on both sides of the Atlantic
Wegener thought the continents were once one large landmass
1912-1960 Eventually interest
decreased because no one could come up with an idea for how the continents moved
Wegener’s theory lacked an answer to this, even with the evidence he found
PLATE TECTONICS
1960 Oceanographers
discovered the Mid-Atlantic Ridge that ran North and South down the Atlantic Harry Hess believed
that new rock material was being pushed up and outward in opposite directions- Seafloor Spreading
1969 Fred Vine and Drummond
Matthews found matching magnetic polarity on both sides of the Ridge to support Hess’ ideas
Sea Floor Spreading was the suffi cient evidence needed to support the theory of continental drift
1970s Detailed maps of the
ocean floor revealed all the features of seafloor spreading
PLATE TECTONICS
Wegener is credited with the theory of continental drift even though other scientists helped support the evidence he had
Many scientists were skeptical about the theoryToday, with technology so advanced, continental drift
has been tested thoroughly and is accepted by almost all scientists.
PLATE TECTONICS
Question: What is Earth’s position in the solar system and in the universe?
6 th Century B.C. Early Greeks believed the sun
was the center of the universe, but lacked any evidence to support it
About 350 B.C. Aristotle’s geocentric model
(Everything revolved around the Earth)
About 150 A.D. Ptolemy backed up Aristotle
with his idea of retrograde motion. His explanation was incorrect but was accepted because he had data and it upheld the idea of an earth-centered universe.
HELIOCENTRIC SOLAR SYSTEM
1543 Copernicus proposed heliocentric (sun-centered) theory based on
his observations of the movement of the stars and planets (claimed they were perfect circles around the sun).
1632 Galileo supported the heliocentric model. With a telescope he observed the phases of Venus; he saw that
Venus sometimes passed the earth and sun, so he assumed it was going all the way around the sun.
1618 Kepler observed Mars and derived mathematical laws of planetary
motion- determined the orbit was elliptical (oval) and not circular. 1784
Herschel concluded that our solar system was a part of a large cluster of stars he called The Milky Way. He saw less stars out from the sun and concluded the sun was the center of the galaxy. He was later proved wrong about the location of the sun but his idea of The Milky Way was correct.
HELIOCENTRIC SOLAR SYSTEM
It took about 2500 years for scientists to understand Earth’s place in the universe. Each one provided information to either change or refine
evidenceToday, scientists are still gathering new evidence
using the Hubble Telescope to further refine the original question.
HELIOCENTRIC SOLAR SYSTEM
Question: What causes diseases?
1800 Ben Rush, a doctor of his time,
believe that imbalance of body fluids caused sickness and thought the best way to cure them was through bleeding, blistering, and vomiting- which were supposed to restore the balance.
1820-1900 People were wary of doctors
and medicine became replaced by trickery. Causes of diseases were not wanted.
Less scientific approaches were used to try to cure sicknesses
Such as hydrotherapy, electrical treatment, and “cure all” medical potions
GERM THEORY
1840s-1870s Scientists found that
increased cleanliness and use of purified water were decreasing the number of childbed fever and cholera cases.
1860s Civil War casualties
forced the medicine field to study the causes of disease and infection in more detail.
1870 Louis Pasteur
developed the Germ Theory of disease- stated that microorganisms were the cause of some diseases.
GERM THEORY
Scientific medical treatment of disease was accepted slowly because people did not trust doctors
Many of the nonscientific methods of treating disease were harmful to patients
GERM THEORY
Question: What is the structure of the atom?
The structure of the atom was not always known even though it was known to be the smallest particle of an element.
ATOMIC THEORY
Early 1800s John Dalton stated that all matter is composed of atoms; he
believed that all atoms were similar in structure but that each element has its own atoms and those atoms could be combined to form compounds.
1897 Joseph J. Thompson discovered electrons, the negatively
charged particles in atoms.1903
Philip Lenard proposed that atoms were mainly empty space, not solid spheres.
1911 Ernest Rutherford concluded that atoms consist of a
massive central nucleus surrounded by space and electrons.1913
Niels Bohr suggested electrons travel in circles around the nucleus.
ATOMIC THEORY
Scientific discoveries are at an ever-increase rate.
Each new discovery leads to more questions and eventually to more research in an effort to answer these questions.
The advancement of scientific discovery can be attributed to an increase in technology.
SCIENTIFIC DISCOVERY
Chapter 17QUESTIONS?