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ASTR 100

  • E2-01: WORLD GLOBE

    E2-01
    Illustrate the globe
    This is just a standard globe of the planet earth with latitude and longitude lines marked.
    E2

  • E2-03: CRATER FORMATION MODEL

    E2-03
    Illustrate how a crater forms as a result of an impact or a blast from below.

    Drop a steel ball onto a dish of sand. The ball becomes partially buried and a crater forms.

    Bury the end of the hose in the sand using the plastic strip attached to the end of the hose, and smooth out the sand. Using lung power, blow in a blast of air and notice the crater that forms.

    A generation ago there was a debate among geologists and astronomers as to the origin of lunar and terrestrial craters. This demonstration illustrates two ways in which craters can form.
    E2, LS2

    e2-03a

  • E2-13: SUNSPOT MODEL

    E2-13
    Show how sunspots are darker than their surroundings due to lower temperatures.

    Three light bulbs are mounted along a rod: two 150 watt bulbs with a 15 watt bulb between them. The lower-power center bulb appears darker, compared to the two brighter bulbs, because it has a lower temperature.

    Sunspots appear darker than the surrounding area because they are regions of lower temperature.
    E2

  • E2-21: PHASES OF THE MOON

    E2-21
    Show the relationship between the phases of the moon and the relative earth-sun-moon positions.
    With the lecture hall dark, a point source illuminates the globe (the slated sphere from A1 is recommended) from various positions. Phases from crescent to full moon show up very clearly.
    A2, LS1

  • E2-22 UMBRA AND PENUMBRA

    E2-22
    Illustrates shadow umbra and penumbra
    The foam ball casts a shadow of each of the two point sources in the box. The umbra is where the two shadows overlap and the penumbra is where only one source is shadowed.
    E2, LS1

    E2-22A

  • E2-33: RETROGRADE MOTION

    E2-33
    Demonstrate the observation of another planet as seen from the earth.
    Turning the crank on the back of the apparatus rotates the two planets around the sun, with the inner planet rotating at about four times the angular speed of the outer planet. The side of each planet opposite the sun is painted black to simulate a shadow. The rod between the two planets aids in fixing the observational line of sight.
    E2

  • E2-35: PLANETS - RELATIVE SIZES MODEL

    E2-35
    Illustrate the relative sizes of the planets

    The "planets" are scaled to their actual sizes so that they may be compared. Each planet is identified.

    In the picture, clockwise beginning at the left rear: Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury, and Pluto.
    E2

  • E2-36: DENSITY STRATIFICATION - FORMATION OF PLANETS

    E2-36
    Demonstrates how density stratification (differentiation) in interior of planets occurs.
    Heavy balls represent dense material (e. g., iron or nickel). Light balls represent light material (e. g., silicates). Use wooden plank to vigorously mix the balls, then remove the plank and watch heavy balls settle. Mixing simulates the hot molten interior of a young planet. Settling simulates differentiation in molten interior of an older planet.
    E2, P4

    e2-36a

  • E2-37: PLATONIC SOLIDS AND KEPLER

    E2-37
    Visualize the Platonic solids and Kepler's dream for using them to explain planetary orbits.

    There are five three-dimensional Platonic solids. The faces of a Platonic solid are identical regular polygons and all vertex angles are equal. These solids are:

    Name..........Number of faces

    Tetrahedron.......4
    Cube...................6
    Octahedron.........8
    Dodecahedron....12
    Icosahedron........20

    As illustrated in the accompanying transparency, Kepler spent most of his life assuming that planetary orbits were circular and trying to use Platonic solids to deduce their radii. Only much later, after he gave up his dream, did he discover his true laws for planetary motion. Although Kepler's original dream was a failure, much of the same mathematical/geometrical spirit prevails in our modern attempts to explain the fundamental nature of matter via symmetry, group theory, field theory, the geometry of various higher dimensional manifolds, and string theory.

    E2

  • E2-41: TRANSPARENT CELESTIAL GLOBE

    E2-41
    Illustrate some relationships between the earth, the sun, and certain heavenly bodies
    A transparent globe designed to teach earth-space relationships at the beginning level of astronomy, the celestial globe features a 4" diameter terrestrial globe mounted with a 12" diameter star globe, plus adjustable sun model. Both globes and sun may be easily set to show the positions of the stars and planets for any time and place.
    E2

  • E2-50: PULSAR MODEL - FLASHLIGHTS

    E2-50
    Illustrate beaming pattern of pulsars and pulsed binary X-ray sources.
    Flashlights are mounted antiparallel to each other on a rod which is mounted at an oblique angle onto a second rod. The second rod is then rotated to obtain the pulsar effect. The angle of obliquity can be easily adjusted.
    FS1

  • E2-61: GALAXY MODEL

    E2-61
    Illustrate our galaxy.

    This is a model of our galaxy, the size of the milky way shrunk to about 50cm diameter, a ratio of 1:2x10+21!! See table of interesting sizes in the Demonstration Reference File, a copy of which is available with the demonstration.

    The red marble locates the approximate position of the solar system.

    FRAGILE! Be careful.

    E2, OS12

  • E2-63: EXPANDING UNIVERSE

    E2-63
    Demonstrate the concept of the expansion of the universe.
    A large balloon is painted with geometrical shapes representing galaxies in the universe. Blow air into the balloon with an air blower to expand the universe.
    I0, office

    e2-63a

  • E2-71: MILLISECOND PULSAR

    E2-71
    To "hear" the signal from a pulsar.
    This audio tape cassette contains the signal from a pulsar converted to audio frequencies.

    Note: requires large audio cart to play in lecture halls.
    E2, FS1

  • E2-72: AUDIOTAPE 14 MIN - NRAO PULSAR

    e2-72
    To listen to a pulsar
    This audio cassette tape contains 14 minutes of pulsar signals converted to audio. Obtained through the NRAO.

    Note: requires large audio cart in lecture halls.
    E2

  • E2-73: AUDIOTAPE 18 MIN - SOUNDS FROM SPACE

    E2-73
    Tape of signals from several early artificial satellites.
    Some of the most significant scientific events leading to the launching of the Echo I satellite on August 12, 1960 are described here. Excerpts from messages received from previous artificial satellites in space are presented, including Sputnik, Explorer, and the Vanguard series. Project Echo sounds are also played, with accompanying narration.

    Note: Requires large audio cart in lecture halls.
    E2

  • F2-12: HOT AIR BALLOON

    F2-12
    Show that hot air is less dense than cold air by operating a hot air balloon.
    A 15-ampere hot air gun is used to inflate a hot air balloon. As the air inside is heated, its density decreases with respect to the cooler outside atmosphere. Within less than a couple of minutes, the buoyant force becomes sufficient that the balloon will rise.

    Invite students to predict what will happen as the air cools.
    OS4

    f2-12af2-12bf2-12cf2-12cf2-12d

  • G3-21 TRANSVERSE WAVES ON A LONG SPRING

    G3-21
    Demonstrates traveling waves

    Clamp the spring to the lecture table and then step back. When you hold the other end with some tension and shake the end with various frequencies, you can illustrate transverse waves traveling along the spring.

    You can move your hand to generate a pulse or wave in the spring. Because of the clamp, the spring acts as a medium with one free end and one fixed end. By changing how far and how fast you move your hand, I can generate different amplitudes and frequencies. If you move my hand farther on each swing, you create a wave with a greater amplitude – the height of each peak is greater. If you move your hand up and down faster, you create a wave with a greater frequency – the number of peaks within a given length is greater.

    With practice, you can also find the natural frequency of the spring and set up standing waves.
    Engagement Suggestion
    • Ask students: “Now that we’ve seen some features of transverse waves, let’s try an experiment. I’m going to send a single upright pulse down the spring. What will happen when it reaches the fixed end? Will it stop entirely, bounce back in the same shape, or bounce back upside-down?”
    • “The pulse returns upside-down!”
    Background
    A transverse wave is one where the direction of oscillation is perpendicular to the direction of propagation. The up-and-down motion of the spring that forms each pulse is at a right angle to the forward movement of the wave. When a transverse pulse reflects off a fixed end, it returns inverted. If instead it had reflected off an open end, it would return upright. We can see this most easily with a single pulse, but this is true of a repeating waveform as well. We see mechanical transverse waves in springs, ropes, and other objects routinely. But another type of transverse wave surrounds us all the time – electromagnetic waves, like light, are transverse waves.
    G3

  • G3-28 SUSPENDED SLINKY

    G3-28
    Shows longitudinal and transverse traveling waves & standing waves
    Transverse or longitudinal pulses can be created by appropriate motion of your hand at one end of the SLINKY. Using your hand you can also create transverse standing waves and discuss the overtone series. Gently vibrating one end of the spring (either by hand or using the motor) at the appropriate frequency creates longitudinal standing waves.
    FS1

  • G4-02 RIPPLE TANK

    G4-02
    Illustrates wave phenomena water surface
    This is a large ripple tank which uses an overhead projector as its light source. It is kept on its own cart along with all accessories. Experiments which can be performed with this ripple tank include: Huygens's principle, plane waves and circular waves, single slit diffraction, double slit interference, interference between two sources, reflection and refraction of waves at a boundary, focusing by a concave reflector, focusing by lenses, and the Doppler effect.
    OS7