The physical phenomenon of dew formation.

Dew is water droplets formed by condensation of water vapor on the ground or near-earth objects due to temperature drop.

1. On a clear, windless or breezy night, water vapor in the air is saturated due to radiation cooling, and condenses into water droplets to form dew or fog (when the temperature is lower than 0℃ or so, it will condense into ice crystals to form frost). After the Millennium solar terms, the summer monsoon will gradually be replaced by the winter monsoon, with more northerly winds, cold air gradually moving south frequently and the temperature dropping.

2. Dew is a physical phenomenon, which is formed by condensation of water vapor on the ground or near-earth objects. On a clear night, the water vapor in the sky will gradually reach saturation due to the radiant heat from the ground and objects. When water vapor reaches saturation, it will condense into water droplets or ice crystals, forming dew or fog.

3. The formation of dew requires two basic conditions: one is enough water vapor, and the other is enough cooling. On a clear night, the ground and objects become cold due to radiant heat, and the water vapor in the sky will condense into water droplets or ice crystals when it meets the cold ground or objects.

The related knowledge of physical phenomena is as follows:

1. Physical phenomena refer to various physical laws and phenomena existing in nature, which can be revealed and understood through observation, experiment and theoretical research. Physical phenomena exist widely around us, including mechanics, optics, electricity, heat, acoustics and other fields. In physics, we study various physical phenomena through experiments and theories.

2. Experiment is the foundation of physics, and all kinds of physical phenomena can be observed through experiments, such as Newton's law of universal gravitation and Einstein's theory of relativity. At the same time, theory is also a very important part of physics, through which experimental phenomena can be explained and various physical laws can be deduced. Physical phenomena can be divided into macro phenomena and micro phenomena.

Macro phenomenon refers to the phenomenon that we can directly observe, such as the movement of objects and the propagation of light. Microscopic phenomena refer to phenomena occurring on atomic and molecular scales, such as wave-particle duality in quantum mechanics and electron orbits in atoms. Various phenomena in physics are interrelated and mutually restricted.