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Simpson and Scarce Theory

Simpson and Scarce Theory

Simpson and Scarce theory is a model used to explain the mechanism of light emission in semiconductors. The theory was proposed by G. Simpson and N. Scarce in the 1960s.

This theory is based on the temperature variations in the various regions of the cloud. a cloud is shown to be traveling from left to right along with the air currents. When these air currents collide with the water particles at the bottom of the cloud, the water drops are broken and carried upwards, unless they combine and remain in a small packet of positive charges. With the collision of water drops the air is negatively charged and water particles are positively charged. These negative charges in the air are at once absorbed by the cloud particles, which move upward with air currents. 
Simpson and Scarce Theory

Metrological and electrical conditions within a thundercloud. A positive charge resides in the upper portion of the cloud above a region of separation from the negative charge in which the temperature is between -10 to 20°C. Thus a net positive charge will occur above the mid-level of the cloud, and the negative charge will be distributed more generally throughout the cloud body. This is how the charge is separated into a thundercloud. Once this is done, the conditions are set for the initiation of a lightning stroke.

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