The Science Literacy Course Eun-Kyung Parkepark/ekpark/JOS12FW-1015.pdf · planets, and transit objects such as meteors or comets - Thousands of visible stars fill the heavens and

Joy of Science The Science Literacy Course

Eun-Kyung Park Department of Physics Faculty of Science, Bd #2, office #2-11-09 TEL/FAX: +81-(0)11-706-4415 Email:[email protected] http://www.sci.hokudai.ac.jp/~epark/ekpark_e.html

Joy of Science Discovering the matters and the laws of the universe

Key Words Universe, Energy, Quantum mechanics, Chemical reaction, Structure of matter

(Earth, Evolution of life, Ecosystem, Environment will be taught in next semester)

Unless otherwise noted, all pictures are taken from wikipedia.org

The Goals of this course

As experiencing various fields of science through this course, Students can organize presentations around the central great ideas rather than specific disciplines, and then can integrate the concepts of each lesson to be related to every area of science.

Enjoy Science!

Course Schedule n  All 15 weeks (Oct. 1, 2012 – Feb. 4, 2013) n  Grades: participation (40%) homework (20%) - biweekly quizzes and final test (30%) discussion (10%) n  Distribution of grades: 30 % Excellent 40% Very Good 20% Good 10% Pass

Textbooks n  Textbook Science Matters: Achieving Scientific Literacy Robert M. Hazen , James Trefil

ISBN-10: 9780307454584 ISBN-13: 978-0307454584 ASIN: 0307454584

n  Reference book The Sciences: An Integrated Approach James Trefil , Robert M. Hazen

ISBN-10: 0470118547 ISBN-13: 978-0470118542

Four Principle Reasons for the Importance of Scientific Literacy

n  Scientific literacy helps consumers make informed decisions.

n  Today’s workplace depends on science.

n  Scientific literacy provides a foundation for teaching children.

n  Scientific literacy allows you to share in the joy of science.

Science as a Way of Knowing

Why Study Science? Science, n  gives us most powerful tool to understand how our world works

and how we interact with our physical surroundings.

n  provides a framework for learning more and tackling new questions and concerns that come our way.

n  helps us to predict and cope with natural disasters, diseases, and to discover new materials and technologies.

n  provides an view of symmetry of the universe and it’s workings form the unseen world of the atomic nucleus to the vastness of space.

The Scientific Method n  Observations: should be re-producible n  Hypothesis: a tentative educated guess by collected a number of facts

which are confirmed observations n  Predictions: led by hypotheses, can be tested by more observations

and experiments

n  Experiments: based on careful measurements n  Scientific Theory: a well-substantiated explanation of the natural world

based on independently verified observations and tests

n  Scientific Law: a regular, predictable pattern of behavior in nature n  Mathematics: the language of science – experimental analyses and

developments of theories

Hypothesis

Initial Observation

Experiment

Observation and analysis of data

Final Hypothesis supported

Theory stated

New experiment

Hypothesis not supported

New Hypothesis

Scientific Method

Discovering laws and matters of the universe

n  By integrating fundamental concepts in physics, chemistry, and biology, we can obtain an interdisciplinary understanding of the evolution of universe, solar system and life on earth n  We can learn - How science works - How it is used to unravel the mysterious of the universe - How physics, chemistry, and biology have developed

The ordered Universe Why do planets appear to wander slowly across the sky?

Stonehenge, Copernican, Galileo Galilei, Mechanics, distance, speed, velocity,

acceleration, vector

October 15, 2012 2nd week

Key Words

Contents

n  Introduction: - Predictability of our physical world - Stonehenge n  The birth of modern Astronomy - Historical background: AD 2nd C ~ 16C - Observations:16~17C n  The birth of Mechanics - Galileo Galilei - The founder of experimental science

1. Introduction

Predictability of our physical world

The universe we are living in is predictable n  Predictability of our physical world: The central principle of science

n The regular passage of seasons - - - …


The universe we are living in is predictable n  Predictability of our physical world: The central principle of science n  The regular passage of seasons - - …

provides a template for our lives - - - …


The universe we are living in is predictable n  Predictability of our physical world: The central principle of science

n The regular passage of seasons - shortening and lengthening of days - gradual changes in temperature …

provides a template for our lives - plant and harvest crops - purchase wardrobes - schedule vacations …

n  Physical events are quantifiable and therefore predictable n  Most predictable objectives in the universe are the lights in the

sky at night - stars and planets


n  Physical events are quantifiable and therefore predictable n  Most predictable objectives in the universe are the lights in the

sky at night - stars and planets à The sky changes, but predictable. à Regularities in the arrangement and movements of stars and planets were noticed by our ancestors: è Knowing the behavior of the sky was an essential part of their lives


n  Knowing the behavior of the sky was an essential part of our ancestors’ lives

- Judging a time to plant crops by a certain place of Sunrise - Harvesting or hunting after sunset are possible at certain times of the month with a full Moon


n  Knowing the behavior of the sky was an essential part of our ancestors’ lives

- Judging a time to plant crops by a certain place of Sunrise - Harvesting or hunting after sunset are possible at certain times of the month with a full Moon è Astronomy, the study of objects in the heavens, was one of the first science to develop


Stonehenge n  The symbol of humankind’s early preoccupation with astronomy n  The great prehistoric monument on Salisbury Plain in southern

England, built in about 2800 BC n  The structure consists of a large circular bank of earth surrounding

a ring of single upright stones

Stonehenge n  Why would ancient people expend such a great effort

to erect one of the world’s great monuments? n  The answer is,

Stonehenge

n  Why would ancient expend such a great effort to erect one of the world’s great monuments?

n  The answer is, it was built to mark the passage of time n  It served as a giant calendar based on the movement of objects in

the sky

Stonehenge



the sky n  Building a structure like Stonehenge requires …

Stonehenge



the sky n  Building a structure like Stonehenge requires accumulation of

knowledge about the sky only through many years of observations èIt is impossible, if the universe is not regular and predictable

Stonehenge

n  It is possible to predict the behavior of the universe we live in, because

observations from the universe show us patterns that occur over and over again

2. The birth of modern Astronomy

Historical background

n  In the night sky, We can see movements of stars, moons, planets, and transit objects such as meteors or comets

- Thousands of visible stars fill the heavens and appear to move each night in stately circular arcs centered on the North Star; closely spaced groups of stars called constellations such as Big Dipper and Leo the Lion

The birth of modern Astronomy

http://physics.weber.edu/schroeder/ua/StarMotion.html

n  In the night sky, We can see movements of stars, moons, planets, and transit objects such as meteors or comets

- Thousands of visible stars fill the heavens and appear to move each night in stately circular arcs centered on the North Star; closely spaced groups of stars called constellations such as Big Dipper and Leo the Lion - Earth’s Moon and other planet’s move across the fixed starry background - Meteors or comets grace the night sky from time to time n  What causes these objects to move, what do those motions tell

us about the universe in which we live?


Historical background

n  What causes these objects to move, what do those motions tell us about the universe in which we live?

n  Most societies before recorded history created legends and myths tied to these movements, but the Greeks devised the first astronomical explanations that incorporated elements of modern science

n  Claudius Ptolemy in AD 2nd C proposed the first widely accepted explanations for complex celestial motions

n  In the Ptolemaic description of the universe - Earth sat unmoved at the center - Around the Earth, on a concentric series of rotating spheres, moved the stars and planets - The model was carefully crafted to take account of observations - Well predicted planetary motions, eclipses and other phenomena


Historical background: Ptolemy

n  Nicolas Copernicus (1473-1543) considered a new hypothesis that was to herald the end of Ptolemy’s theory, in <On the Revolutions of the Spheres>

n  In Copernican description - His idea kept the notions of a spherical universe, and even the ideas of spheres rolling within a sphere - But, the model of the heavens are in which the Sun, rather than Earth, is at the center! n  It was the first time in over a millennium, the Ptolemaic system was

faced by a serious challenger!!! è


Historical background: Copernicus

n  Nicolas Copernicus (1473-1543) considered a new hypothesis that was to herald the end of Ptolemy’s theory, in <On the Revolutions of the Spheres>

n  In Copernican description - His idea kept the notions of a spherical universe, and even the ideas of spheres rolling within a sphere - But, the model of the heavens are in which the Sun, rather than Earth, is at the center! n  It was the first time in over a millennium, the Ptolemaic system was

faced by a serious challenger!!! è Humankind was no longer at the center of the universe


Historical background: Copernicus

Historical background: Ptolemy and Copernicus


Ptolemaic system Copernican system

Observations: Tycho Brahe and Johannes Kepler

n  The both Ptolemaic and Copernican theories described possible universe, and astronomers’ task was to decide which model is best describes the universe we actually in.

è need to compare the two competing hypothesis to observations, but the differences from the two were too small with equipment available at the time n  Tycho Brahe (1546-1601) accumulated extremely accurate data on

the positions of the planets n  Johannes Kepler (1571-1630) analyzed Tycho’s data and

summarized in three mathematical statements about the solar system - Kepler’s (first) law: all planets, including Earth, orbit the Sun in elliptical, not circular, paths. n  Earth is not at the center of the universe, that planetary orbits are not

circular!!!


3. The birth of Mechanics

Galileo Galilei n  Galileo Galilei (1564-1642): Physicist, Mathematician, and philosopher. The first person to record observations of the heavens with a “telescope” n  To understand Galileo’s study moving objects, ultimately to

understand the workings of the solar system, we have to begin with precise definitions of three terms:

speed, velocity, and acceleration

The birth of Mechanics

Galileo Galilei: Birth of Mechanics

n  Mechanics: the branch of science that deals with the motions of material objects such as

- a rock rolling down a hill - a ball thrown into the air - a sailboat skimming over the waves … - planets orbiting around the Sun n  Until 17th C, why things move the way they do was not understood


n  Definitions of speed, velocity, and acceleration Speed: distance divided by the time it takes to travel that distance Ex) 60 km/hr (scalar) Velocity: the same numerical value as speed, but including direction Ex) 60 km/hr due west (vector) Acceleration: A measure of the rate of change of velocity. (vector) Whenever an object changes speed or direction, it accelerates


Mechanics: speed, velocity, acceleration

The founder of experimental science n Galileo devised an ingenious experiment to determine the

relationships among distance, time, velocity, and acceleration n  Greek philosophers had taught heavier objects must fall faster than

light ones è proved Not true by Galileo! n  He showed that at Earth’s surface all objects accelerate at the

same rate as they fall downward (the famous episode of an experiment from Leaning Tower of Pisa, probably never performed??)


The founder of experimental science

n  To describe falling objects, it is necessary to precisely measure two variables: distance and time.

n  Galileo constructed a special apparatus designed purely to measure acceleration, with an inclined plane crafted of brass and hard wood, by increasing the angle of elevation of the plane


10o

20o

30o

The founder of experimental science

n  He found that any accelerating toward Earth’s surface, no matter how heavy or light, falls with exactly the same constant acceleration.

In this special case where an object is falling freely toward Earth’s surface, the accelerating rate is a constant number written by an alphabet g. (cf. the Moon has a very different surface accelerations)


1,000kg 1kg

Acceleration = g Acceleration = g

Surface of Earth

Free falling

n  In general, the velocity of an accelerating object that starts from rest is proportional to the length of time that it has been falling

n  Galileo’s work also demonstrated that the distance covered by an

accelerating object depends on the square of the travel time.


Velocity = constant a x time

Distance traveled = ½ x acceleration x time 2

Galileo’s work in speed, velocity, acceleration

Next topic:

Unification of the laws of the Earth and the Universe: Chapter 1

<Sample materials for group discussion> n  http://www.ted.com/talks/

richard_dawkins_on_our_queer_universe.html n  http://www.pbs.org/wgbh/nova/earth/galileo-big-mistake.html

Documents

The Science Literacy Course Eun-Kyung Parkepark/ekpark/JOS12FW-1015.pdf · planets, and transit objects such as meteors or comets - Thousands of visible stars fill the heavens and