Cloud

A cloud is a visible mass of condensed droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. The branch of meteorology in which clouds are studied is nephology.

On Earth, the condensing substance is water vapor, which forms small droplets of water or ice crystals, typically 0.01 mm in diameter. When surrounded with billions of other droplets or crystals, they are visible as clouds. Dense deep clouds exhibit a high reflectance throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light very efficiently, so that the intensity of the solar radiation decreases with depth into the cloud, hence the grey or even sometimes dark appearance of the clouds at their base. Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by non-white light, such as during sunrise or sunset, may be colored accordingly. In the near-infrared range, however, clouds would appear very dark because the water that constitutes the cloud droplets strongly absorb solar radiation at these wavelengths.

Sri Lankan Ayurvedic tradition

Sri Lanka, with an archeological history dating back to at least 30,000 B.C., has its own indigenous scheme of medicine. This system has been practised for many centuries in the island nation. The Sri Lankan Ayurvedic tradition is a mixture of the Ayurveda systems of North India, the Siddha system of South India, Unani medicine from the Arabs, and most importantly, the Desheeya Chikitsa, which is the indigenous medicine of Sri Lanka.

The word "Ayurveda" translates into English as the "science of life" . Considered to be the oldest healing science in the world, this ancient medicine is practiced extensively in Sri Lanka and India. Passed down through time, this system focuses on the connection between the body and the mind. Using natural cures, Ayurveda aims to maintain the body in a balanced state of health.Sri Lanka developed its own Ayurvedic system based on a series of prescriptions handed down from generation to generation over a period of 3,000 years. The ancient kings, who were also prominent physicians, sustained its survival and longevity. King Buddhadasa , the most influential of these physicians, wrote the Sarartha Sangrahaya, a comprehensive manuscript which Sri Lankan physicians still use today for reference.