the intensity of Solar radiation as a function of wavelength is presented. The yellow part represents the intensity of Sunlight at the top of the atmosphere, while the red part is the same Sunlight intensity measured at Sea Level. We see that the Sea Level radiation does not match the radiation at the top...
A solar cell is the basic element of solar photovoltaics. It is built out of semiconductor material, and usually its surface area is no greater than 10×10 cm. Its surface color is usually black or dark, for obvious reasons, that is, to reflect as little of the solar energy as possible. When exposed to...
Every solar cell is based on a very fundamental physical principle which involves interaction between light and electrons. The light (or photons – small packages of light energy) is of course coming from the Sun, and the electrons are present in the material out of which the solar cell is built. The photons come...
The name platinum comes from the Spanish word platina which means “little silver”, obviously referring to its shine and appearance. The modern history of platinum starts in the 18th century. The scientists of the medieval times, the alchemists, knew and recognized as metals seven elements: gold, silver, mercury, tin, iron, copper, and lead. There...
Concentrating on our immediate environment, feng shui can help us find the delicate balance needed to create harmony in our homes – harmony primarily in the sense of unrestricted energy flow and its interaction with humans. The living room is the center of our home where members of the family gather in order to...
They should be drawn to each other quite strongly! So, on one hand we have the gravity that would eventually cause the Universe to contract into itself. On the other hand we supposedly have this “dark energy” which appears to be pushing apart the galaxies faster than the gravity can pull them together. There...
Everybody has heard of silicon, Si, which is an elemental semiconductor. That means that the semiconductor crystal is made out of many atoms of the element Si. No other element is needed, but the atoms within the crystal are required to follow a special pattern, and form the so called, tetrahedral arrangements. One silicon...
It is indeed a riddle as to how these images have been made. They can be seen hundreds of individual images, from simple geometrical patterns to sophisticated spiders, hummingbirds, monkeys, and lizards. They are supposed to be created some 2000 years ago by the Nazca people. Their culture is thought to have reached its...
Hydrogen is the first element in the periodic system of elements, and simplest element known to man. It consists of one proton located in the atomic nucleus, and one electron orbiting around the nucleus. Hydrogen is the most abundant element in the Universe, by far more abundant than helium, oxygen and carbon. On Earth,...
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