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May The Earth Be Revolving Around The Sun?
Young scholars trace the beginning of the heliocentric theory of the solar system--the idea that the solar system revolves around the Sun--to an observation by the Greek astronomer Aristarchus, which convinced him that the Sun was much...
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How Distant is the Moon?--2
Students examine total eclipses of the Sun and their limited regions of totality. They explain that this limited view occurs because the Moon is close enough to us for different points on Earth to view it differently.
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How Distant Is The Moon?
Students discover how Aristarchus, a Greek astronomer around 230 BC, used a simple observation of the eclipse of the Moon, plus clever reasoning, to deduce the distance of the Moon. They practice the same calculation technique.
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Parallax
Students discover how astronomers used the diameter of the Earth's orbit around the Sun as a baseline for estimating the distance of some stars, and the meaning of "Parsec" and "light year."
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Precession
Students explain how Hipparchus, around 130 BC, used a shift in the predicted location of a lunar eclipse to detect a slight shift in the path of the Sun around the sky. They examine the elliptical orbit in which the Earth travels around...
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Coordinates
Young scholars use cartesian coordinates (x,y,z) in 3-dimensional space. [Optional: appreciate there exist two ways of defining the z axis, and which of them is used.] They become familiar with the tools and terms used by surveyors.
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Navigation
Students study the basic methods for finding one's position on Earth. Latitude can be deduced from the height above the horizon of the pole star or of the noontime Sun, while longitude requires an accurate clock giving universal time.
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The Sundial
High schoolers explain the design, principle and orientation of a sundial, the type with a gnomon pointing towards the pole of the heavens. They construct a model sundial from paper.
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Stargazers And Skywatchers
Students recognize the daily motion of the Sun across the sky, defining the main directions of east, west, south and north. They see how the first calendars were based on changes in the Sun's noontime elevation, and on locations of...
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Stargazers and Skywatchers
Students are introduced to the apparent motion of the Sun across the sky and the way it changes in summer and winter.
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The Path of the Sun, the Ecliptic
Students are introduced to the ecliptic, the zodiac and the apparent motions of the Sun, Moon and planets across the sky.
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The Discovery of the Solar System
Students explain the observed motion of the planets. The inner ones move back-and-forth across the position of the Sun, while the outer ones usually advance in one direction, but with occasional temporary reversals known as "retrograde...
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Stargazers and Skywatchers
Students observe the daily motions of the sun and relate them to the functions of a sundial. They determine the locations of sunrises and sunsets and determine how the elevation of the sun effects temperature.
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The Celestial Sphere
Pupils are introduced to the celestial sphere, describing its apparent rotation and the special role of the pole star.
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The Path of the Sun: The Ecliptic
Students investigate the celestial sphere and the paths it takes in the solar system.
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Finding the Pole Star
Students study the constellations fo the Big Dipper and Cassiopeia and their use in finding the Pole Star. They realize that other celestial objects--Sun, Moon and planets--share the rotation (and hence rise and set), even though their...
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Seasons of the Year
Students examine how the link between the tilt of the Earth's axis to the ecliptic and seasons of the year--length of day, effectiveness of sunlight, polar day and night, and seasons south and north of the equator, as well as near it.
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The Angle of the Sun's Rays
Young scholars study elevation of the Sun above the horizon and the angle of the rays and their heating power.
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Newton's 3rd Law
Students examine how the formal definition of Newton's 3rd law: forces always originate in pairs, equal in magnitude and opposite in direction. They also examine how the informal, qualitative version: Each action has an equal and...
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Motion in a Circle
Students explore uniform circular motion, and the relation of its frequency of N revolutions/sec with the peripheral velocity v and with the rotation period T. They examine how uniform circular motion is a type of accelerated motion.
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Frames of Reference: The Basics
Learners learn the concept of frames of reference in physics. They examine how two frames of reference, each moving with respect to the other with a constant velocity v (constant speed, constant direction).
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Airplane flight
Students learn the basic concepts about airplane flight. They learn the reason jetliner wings are swept back and why jet engines have replaced propellers in high-speed flight.