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PHYS115

  • L1-03: LIGHT BULB WITHOUT VACUUM

    L1-03
    Show what happens to a lighted filament in the presence of air.
    Turn on the light bulb so that it burns like usual. Gently position the drill against the bulb and turn it on; it drills through the glass in a few seconds. When air (oxygen) enters the bulb it rapidly burns up with a large vapor cloud.

  • L4-02 REFRACTION - BEER MUG IN WATER

    L4-02
    Illustrates refraction
    Due to refraction of the light at the walls of the mug, the mug looks like it has very thin walls and is really filled with liquid. When the mug is placed into water, as in the photograph, the real situation becomes apparent: the mug has very thick glass walls, and holds much less liquid than you think

  • L4-03 REFRACTION - ROD IN WATER

    L4-03
    Demonstrates refraction
    The rod, inserted into the water tank and viewed from an angle, shows a discontinuity at the surface of the water. Insert the other end of the rod at an angle into the water; the rod looks bent when viewed at an angle.

    Invite different students to view the tank from different angles and draw what the rod looks like. Have them compare their experiences and discuss.
    L4

  • L4-05: REFRACTION IN FISH TANK - PORTABLE

    L4-05
    To illustrate refraction.
    Due to refraction, the single fish hanging in the corner of the tank, appears to be one, two, or three fish (as in the photograph), depending on the surface(s) through which it is viewed.

    l4-05

  • L4-06 REFRACTION IN CLOUDY WATER

    L4-06
    Demonstrates a light ray bends when it enters a different medium at an oblique angle.
    The ray from the laser refracts when entering the surface of the cloudy water. The path of the laser beam in the water may be rendered more visible by adding a touch of powdered creamer to the water.

  • L4-31 DISAPPEARANCE OF GLASS IN LIQUID

    L4-31
    Demonstrates how index of refraction affects what wesee in a fluid bath
    Glass seems to disappear when immersed in a liquid with the same index of refraction. The bottles, left to right, contain air, water, and two with microscope immersion oil, a liquid with almost the same index of refraction as glass. In the immersion oil, the glass shaft is almost invisible! An air bubble moving up and down in the shaft takes on an odd appearance, as it will be constrained by the shaft but will appear to be moving in free space.

    A video camera is optionally available to make this more visible in large lecture halls.
    L4

  • L5-13: PLEXIGLASS SPIRAL WITH LASER

    L5-13
    Demonstrate total internal reflection with laser light.
    Due to total internal reflection the light from the laser remains mostly confined within the spiral plexiglass rod, and only exits at the end, where the angle between the surface and the incoming light exceeds the critical angle. Actually, some light escapes at scratches along the spiral, as can be seen in the photograph.
    L5, OM1

  • L5-14: LASER AND PLEXIGLASS TUBE

    L5-14
    Demonstrates total internal reflection
    The laser beam enters the plastic tube at a cutout along the top edge, and follows around the tube while spiralling downward

  • L5-23 FIBER OPTICS TREE

    L5-23
    Demonstrates total internal reflection
    An array of optical fibers is mounted above a light source with coloured filters. The light is guided along the fibers by total internal reflection, creating an attractive display.
    L5

    Geometrical Optics

  • L6-08: REAL IMAGE OF CONVERGING LENS - LIGHT BULB

    L6-08
    Show the real image of a converging lens.
    An incandescent bulb with printing on the top is used as an object to be imaged with lenses of different focal lengths. Hold the lens above the light bulb at a distance slightly greater than the focal length of the lens to cast an image of the trademark onto the ceiling. Change lenses to change the magnification. (10cm and 20cm focal length lenses tend to work best in most rooms, but 5cm, 30cm, and possibly others can also be available upon request.)
    OM1, LS1

  • N1-41: RAINDROP RAY MODEL

    N1-41
    Illustrate formation of a rainbow.
    This is a large roughly scaled model showing the refraction of light rays in a raindrop leading to the formation of a rainbow.

    ge

  • N2-05 DIFFRACTION SPECTRA - MISCELLANEOUS TUBES

    N2-05
    Shows several atomic and molecular line spectra
    Use hand-held diffraction gratings to show a number of line spectra. Many of these tubes are rather weak, so this one works best for smaller groups where observers can get close to the light. Sources, which must be inserted and removed as needed by the instructor, include: hydrogen, helium, neon, argon, xenon, mercury vapor, iodine, chlorine, and oxygen (atomic spectra), carbon dioxide, water vapor, and air (molecular spectra).
    N2

  • O1-01: EYE MODEL - OPTICS

    O1-01
    Demonstrates optics of the eye and corrections of optical defects
    The eye model is an oval tank, filled with water representing the aqueous humor, with a lens representing the eye lens on one end and a screen representing the retina with three positions: normal, nearsighted, and farsighted.
    O1

  • O2-03: PERSISTENCE OF VISION - MAGIC WAND

    O2-03
    Demonstrates the persistence of vision
    The slide of Einstein (or any of your favorite slides) is focused a few feet from the projector, but unfocused where it strikes any surface on which it might be identifiable. When a white stick pointer is moved rapidly up and down through the focal plane the image of Einstein can easily be identified.

  • P2-24: GIANT-LIGHT BULB

    P2-24
    Demonstrate color and intensity changes of blackbody radiation with temperature.
    The giant (1500-Watt) light bulb is connected to a transformer. With a low current, the filament is dim and orange. As the current is increased, the filament is seen to get brigher and whiter.
    P2

    p2-24ap2-24b