Coherence is a measure of how well a signal, such as a optical wavefront, correlates with itself. For example, if you measure a peak at one point in space and time, what is the chance that you will measure a peak at another space and time? This hints that there are actually two forms of coherence, one related to time and the other to space.
Temporal coherence looks at how well radiation measured at one single point correlates over time. In other words, if you measure a peak at one moment in time, how well can you predict that you'll measure a peak at another moment in time? Temporal coherence generally requires a small spread in wavelengths and a source which emits light in-phase. Lasers typically have high temporal coherence, while sunlight, which has a broad emission spectrum, has a low temporal coherence.
But that's not the end of the answer.
The other type of coherence is spatial coherence, and relates to how well two points on an emitter are correlated. One classic way of demonstrating spatial interference is the double-slit experiment: put two small slits in a sheet, and check to see that the light from the slits interferes constructively. Spatial coherence generally requires a small degree of angular spread. Again, most lasers have high spatial coherence. Sunlight also has high spatial coherence: because the sun is so far away, the rays of light are almost parallel.
The coherence of sunlight has been studied since 1869 (Agarwal et al, "Coherence properties of sunlight", Optics Letters 29, p. 459, 2004) -- but even with more than a century of coherence, the subtle difference between spatial and temporal coherence can be tricky.
The source of natural white light is the sun.
The Sun
I don't think so. Coherence is defined for light of a single wavelength.
Sun
the sun
the sun is the primary source of light
Yes, the sun is a light source because it shines light on earth.
Yes, the sun is a light source because it shines light on earth.
It is the phase, which can be measuerd with these type of coherence.
No- it reflects the natural light of the sun, so the sun is the source.
The Sun is a light source Something that makes light.
The sun is a source of light, but it is not a planet.
the sun
The sun is an independent light source.
sun light
No, the Sun is not the only light source in the univrse. Every star is it's own light source, just as the sun is, but due to there distance they are not very effective. The Moon also creates a light source, because it reflects the light from the Sun back to earth. In the same way, if we where on the Moon, the Earth would be a light source, reflecting the light from the Sun at the moon.
The source of natural white light is the sun.