Aurinkokellot

Aurinkokellot are Finnish instruments that tell time using the position of the sun. They function by casting a shadow from a gnomon onto a calibrated surface, indicating the hour. The design of an aurinkokello varies, with common types including horizontal, vertical, and equatorial sundials. Horizontal sundials are placed on a flat surface, while vertical ones are often integrated into walls. Equatorial sundials have their plate parallel to the Earth's equator, making them accurate throughout the year. The accuracy of an aurinkokello depends on its proper orientation and the latitude at which it is placed. They require direct sunlight to operate and do not function at night or on heavily overcast days. Historically, aurinkokellot were essential for timekeeping before the widespread availability of mechanical clocks. Today, they are primarily decorative or educational tools, appreciated for their historical significance and elegant design. Many public spaces and gardens feature aurinkokellot as artistic installations. Their continued presence reflects a fascination with the relationship between celestial mechanics and human measurement of time.