Follow

Stars

  • E1-21: GRAVITATIONAL LENS OPTICAL MODEL

    E1-21
    Demonstrate optical characteristics of a gravitational lens.

    The lens shown in the top photograph above is a plano-convex lens whose focal characteristics model that of a gravitational lens. The shape of the lens, described in one of the reference articles in the reference list linked below, is seen in the photograph at the right.

    The experimental setup is shown in the second photograph. The distant "star" is formed by a hole in a piece of black paper or foil in front of a light source. The star can be moved by sliding it left-to-right along the optical rail behind the gravitational lens, in the same plane as the observer (video or other camera). Adjusting the height of the camera will put the observer slightly out of the plane of the motion of the star and axis of the gravitational lens. These cases are shown below.

    An mpeg video shows a star passing directly behind the gravitational lens, where the star is represented by a small disc of light. The camera, in the plane of the motion, records the light from the star as the star passes DIRECTLY behind the gravitational lens. The ring of light created when the distant star is EXACTLY in line with the gravitational lens and the observer is called the Einstein ring.

    Another mpeg video shows the situation where the distant star is slightly above the plane of the gravitational lens and the observer.

    This device was designed and produced by physicist Sid Liebes, an expert on gravitation and relativity, and author of several of the reference works, including both the design and application of the lens.

    This additional animated video shows what one might observe when a background galaxy passes on the opposite side of a black hole from the observer.

    E1, OM1, LS1, L6

    e1-21a e1-21b

  • E2-11: SOLAR PLASMA MODEL

    E2-11
    Mass driver and ring heater show coronal holes and coronal heating.
    Hold down the ring to simulate confined plasma in a solar coronal loop; it will heat up much as does the solar plasma. Let the ring go and it will "shoot" away from the AC fields much like the plasma shoots out of coronal hole.
    K2

  • E2-12: FUSION MODEL

    E2-12
    Demonstrate how nuclei attract each other if they come close enough together.

    Let the magnets snap together as you discuss how they do work and in the process become slightly less massive, as in E=mc^2. Then discuss the analogy to protons combining to form deuterium and then helium while releasing energy.
    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

  • E2-43: ROTATING STAR FIELD

    E2-43
    Show the apparent motion of the night sky.
    The star field is painted onto the plate with its pivot passing through the North star.

  • E2-44: BINARY STAR MODEL

    E2-44
    Illustrate the orbital motion of a binary star system.
    This common optical device consists of a hemispherical mirror with a ball hanging at its center of curvature. When the ball is displaced and started into circular motion around the center of curvature, the real image of the ball also moves around the center of curvature on the opposite side of the center of curvature from the actual ball. This would represent the orbits of a binary star system where the masses of the two stars are approximately equal. Owing to the rather ghostly appearance of the image, this model is particularly suitable for illustrating a binary system in which one of the stars (the image) is a black hole.
    L3

  • E2-45: ECLIPSING BINARY STAR MODEL - LIGHTS

    E2-45
    Show how we view a rotating binary star.
    The two bulbs, one with less intensity than the other, are rotated about the axis of the stick. This shows the intensity variation observed for a binary star with two stars of differing brightness.

  • E2-46: ECLIPSING BINARY STAR MODEL - SPHERES

    E2-46
    Illustrate the orbits of stars in an eclipsing binary.
    The model consists of two spheres, each representing a star, which are mounted on the ends of a dowel rod. The rod can be rotated, showing how eclipses can occur and at what period the orbital velocities of the stars can be found.
    E2, FS2

  • E2-47: TWINKLING STAR

    E2-47
    Show how air currents cause the "twinkling" of a star.
    A laser beam is directed on a distant wall or screen. When the heater is positioned below the laser beam, hot air convection currents and density changes cause the beam to move continuously, or "twinkle."
    FS1, I0

    e2-47a

  • E2-49: PULSAR MODEL - RADIOWAVES

    E2-49
    Show the changing field pattern from a rotating dipole.
    Position antenna so that the electric field from the transmitter picked up by the receiving antenna lights the lamp on the antenna. Then rotate the transmitting antenna with its stand, causing the light to turn on and off, dependent on the dipole radiation pattern of the antenna.

    e2-49a

  • 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

  • E2-51: GRAVITATIONAL COLLAPSE - MODEL

    E2-51
    Model gravitational collapse.
    Ring magnets are placed around the vertical rod with similar poles adjacent to each other. As more magnets are piled on, the weight of the magnets overcomes the opposing magnetic force, eventually causing "gravitational collapse."
    E2

  • E2-53: STELLAR EVOLUTION - HYDROGEN BURNING

    E2-53
    Provides models for hydrogen burning to produce helium in stars via the proton-proton chain.

    Step 1: Two protons (medium size pink balls at the left) meet to form a deuteron (large blue ball), emitting a positron and a neutrino (two small orange balls).

    Step 2: The deuteron combines with a proton to form He3 (triplet of pink balls), emitting a photon (not shown in photograph).

    Step 3: Two He3 nuclei combine to form He4 (big blue ball) plus two protons (medium size pink balls). The process then repeats. Note that steps 1 and 2 must occur twice before step 3 can occur.

  • 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

  • P4-61: CHAIN REACTION MODEL

    P4-61
    Demonstrate a molecular chain reaction, either controlled or uncontrolled.
    Dominoes can be set up as illustrated to demonstrate a controlled chain reaction. An uncontrolled chain reaction can be demonstrated by setting up the blocks so that each block knocks down two other blocks.

  • P4-62: CHAIN REACTION - MOUSE TRAP VIDEO

    P4-62
    Model of uncontrolled nuclear chain reaction.

    Ping pong balls are positioned on each loaded mousetrap. When a ball is thrown into the box from a hole in the top, it releases the trap which it hits, adding energy to the two balls involved. Each of those balls then hits another trap or two, multiplying the effect. This demonstration was invented by the Walt Disney company in early 1950s as a way to explain to the public how an atomic bomb works.

    PLEASE NOTE: The video is available below.

    p4-62ap4-62cp4-62b