Täysvarjo

Täysvarjo is a Finnish term that translates to "total shadow" or "umbra" in English. It refers to the darkest part of a shadow where all direct light sources are completely blocked. In astronomical contexts, täysvarjo is the darkest, central region of a shadow cast by a celestial body, such as the Moon or Earth. During a total solar eclipse, the täysvarjo of the Moon falls upon a specific area of the Earth, creating a phenomenon where the Sun is completely obscured.

The concept of täysvarjo is also relevant in everyday lighting and photography. When an opaque object blocks a light source, it casts a shadow consisting of two parts: the täysvarjo and the penumbra. The penumbra is the lighter, outer part of the shadow where only some of the light is blocked. The size and sharpness of the täysvarjo depend on the size of the light source and the distance between the object and the surface where the shadow is cast. A smaller, more distant light source will produce a sharper and more defined täysvarjo. Conversely, a larger or closer light source will result in a larger and fuzzier täysvarjo, with a more extensive penumbra. Understanding täysvarjo is crucial for accurately predicting eclipse paths and for controlling light and shadow in visual arts and design.