Tellurium N
The particular innovations are the use of a Fresnel lens to produce an extra bright and parallel light beam which illuminates the earth globe completely.
Further the focussing of a light point on the globe to demonstrate the apparent movement of the sun between the tropics and the use of a horizon disc with shadow-pin figure to show the position of the sun by the shadow fall.
The Tellurium N was designed by Prof. Dr. J. Newig, Kiel in cooperation with Cornelsen Experimenta.
The Fresnel lens:
A short focal length provides a directed, parallel light with the result that a full half of the globe is illuminated and the shadow line (day and night) corresponds with the nature.
Formerly designed Telluriums are not able to show it like this.
The three positions of the Fresnel lens:
- Day and night, seasons: The globe is fully illuminated and the shadow line is clearly visible.
- Tropics (sun-point): The lens focuses a small light point with a ‘hale’ on the centre of the globe. When the earth is turned around the sun the light point moves across the equator between the northern and southern tropic.
- Lunar phases: The moon will especially be illuminated. When the moon is turned around the earth by hand the lunar phases and the eclipses can clearly be demonstrated.
Age 8-18
Technical specifications
Complete with power supply unit, dust protection cover, felt-tip pen, cloth, spare bulb and manual
Technical data:
Globe dia.: 15 cm
Lens dia.: 16 cm
Lamp: 12V/20W quartz-iodine
Size: 720 x 370 x 250 mm
Mass: 4 kg
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1 - The earth, a gyroscope in space
experiment "The earth, a gyroscope in space"
The Tellurium shows us the movements of the earth around the sun and those of the moon around the earth.
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2 - Day and night
experiment "Day and night"
We have to make it clear to the pupils that this conformity to a law applies to all corresponding celestial bodies of spherical shape, thus, e.g., to the moon, but also to our neighbouring planets. The same way as the moon sometimes is very brightly or practically hardly visible, also the planets change their brightness.
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3 - Midday line and division of hours
experiment "Midday line and division of hours"
Overview of the origin of the times and the corresponding sun position.
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4 - Polar day and polar night
experiment "Polar day and polar night"
Explanation of the two phenomena of polar night and polar day.
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5 - The Tropic of Cancer and Capricorn and the tropics
experiment "The Tropic of Cancer and Capricorn and the tropics"
Investigate the phenomena of the tropics using the sun point.
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6 - The seasons
experiment "The seasons"
Showing the origin of the seasons.
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7 - Lengths of day and night in various latitudes
experiment "Lengths of day and night in various latitudes"
Point out the different times of day/night at different latitudes and the different seasons.
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8 - The times of day
experiment "The times of day"
The times of day at different earth-sun positions at different latitudes are shown.
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9 - The phases of the moon
experiment "The phases of the moon"
Observing the moon phases.
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10 - The eclipses
experiment "The eclipses"
Pointing out the origins of the eclipses.
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11 - The tides
experiment "The tides"
Explain the phenomenon of tides.
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12 - Measuring the earth´s circumference
experiment "Measuring the earth´s circumference"
Show how to determine the circumference and radius of the Earth.
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13 - Geo-stationary satellite
experiment "Geo-stationary satellite"
Show how to determine the circumference and radius of the Earth.
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14 - Daylight and Shadow for the determination of the islamic pray time
experiment "Daylight and Shadow for the determination of the islamic pray time"
Explain how Muslim prayer times come about.
- 1 × Marker, water-soluble
- 2 × Cleaning cloth
- 1 × Tellurium N
