Friday, January 11, 2008
Announcements:
- If you are not yet enrolled in this Physics 101 course and its
corresponding
lab, please see Sallie Anderson in Phillips 278.
- Labs start next Tuesday - The lab schedule is posted outside the
lab room (Phillips 275), in the display case
near the north entrance of
Phillips hall, in the front of your lab manual, and on the physics lab website.
Assignments:
- If you have not already done so, fill out a Student Survey for
class
participation credit.
- Turn in your answers to the two questions that are due today:
- What topics in the textbook interest you the most? Examine the
table of contents and identify five topics by chapter and section
number that particularly interest you and should not be left out of the
course.
- Read Chapter 2 before the next class next, and be prepared to
answer questions.
Class Discussion
- Comments about the Student Survey and Pre-test
- Chapter 1 - The Way of Science
- Reasons for learning science: expanded awareness and
improved scientific literacy to help solve human problems in our modern
world. Example: Dihydrogen Monoxide
- Physics is the study of
the natural world and the laws that govern matter, energy, space, and
time. It is the most fundamental science.
- The scientific process
relies on both observations
and theory to explain
phenomena and make predictions. Based on observations, a hypothesis is developed, and once
validated by additional empirical evidence, is refined into a theory that can be used to make
predictions. A scientific principle
or law is one fundamental idea
within a more general theory, but even scientific laws are not absolute.
- Astronomy is the
scientific study of the heavens, while astrology
is the belief that the positions of the stars affect human behavior.
- Ponderable: Why is the period of revolution for Earth
around the Sun not one day?
- The planets
(wanderers) were identified by the Greeks by their slow movement
relative to the other stars.
- Aristarchus proposed
that the sun and not the Earth was at the center of the universe, but
most Greeks, including Pythagoras,
believed that the planets, Sun, and stars moved around the Earth in
circular paths.
- Ptolemy proposed (c.
100 A.D.)a modified theory to explain the retrograde motion and
variable brightness of the planets by using epicycles in addition to
the circular paths. It was a good theory, but not as simple as
what pythagoreans would have liked. This strive for simplicity in
a theory is sometimes called Ockham's
razor (from William of Ockham, 14th century).
- Ponderable: What constitutes a good theory?
- Copernicus proposed a
simpler theory that explained the observations of the planets.
This heliocentric theory was the start of the Copernican revolution and
the dawn of the modern age - if Earth is not the center of the
universe, then perhaps we humans are not as unique as once believed.
- What is a planet?