“The solskuggerfjol (sun shadow board) mentioned in the History of the Faroe Islands, was used for determining latitude. It was a circular wooden board about 250 to 300 millimeters in diameter. In the center was a gnomon, the height of which could be set to the time of the year. To keep it level, the board was placed in a bowl of water. The shadow of the noon sun was observed. A circle on the board gave the line the shadow should reach if the ship was on the desired latitude. If the shadow was beyond the line the ship was north of this latitude; if inside, the ship was south of it.”
Another navigational innovation was the sunstone
“Iceland spar, possibly the Icelandic medieval sunstone used to locate the sun in the sky when obstructed from view.”
For navigation we use the stars and the sunFor sky watching there is are many great smart phone applications like Mobile Observatory, which in addition to sunrise and sunset calculate other neat things like twilight and the “golden hour”. The golden hour is the sweet-spot the hour before the sunsets. Photography photograph in this hour to get beautiful results for sunrises and normal photography. Filmmakers shot films at these times to get stunning background for their films.
A science writer made the observation that Earth is our observatory for seeing the stars. It is our very own spaceship. Understanding how the Earth works and how to care for it will give us and future generations of humanity a long future. It is the same care we would apply Titan and Europa two moons of Jupiter that are most likely to have life.
Tromso and the rest of Norway are high enough in the northern latitude to experience the northern lights. These light are the result of solar storms hitting the earth’s magnetic field displaying a beautiful scene like this one from Tromso. The earth’s magnetic field is the protective shielding of spaceship earth.