Tímasamhengi

Tímasamhengi is an Icelandic term that translates to "time coherence" or "temporal coherence" in English. It refers to the degree to which the phases of different parts of a wave or signal are related to each other over time. In simpler terms, it describes how predictable a wave's behavior is from one moment to the next.

A wave with high temporal coherence exhibits a consistent and predictable phase relationship over a significant duration. This means that if you know the wave's phase at a particular time, you can accurately predict its phase at a later time. Lasers are a prime example of sources that produce highly temporally coherent light. This property is crucial for applications like interferometry and holography, where precise measurements and reconstructions rely on the stable phase relationship of light waves.

Conversely, a wave with low temporal coherence has rapidly changing and unpredictable phase relationships. Light from an incandescent bulb, for instance, has very low temporal coherence. The photons emitted are largely independent, and their phases are not correlated over any meaningful duration. Understanding temporal coherence is fundamental in various fields of physics and engineering, including optics, signal processing, and quantum mechanics, as it dictates the behavior and applicability of wave phenomena.