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A panoramic radiograph is a panoramic scanning dental X-ray of the upper and lower jaw.It shows a two-dimensional view of a half-circle from ear to ear. Panoramic radiography is a form of focal plane tomography; thus, images of multiple planes are taken to make up the composite panoramic image, where the maxilla and mandible are in the focal trough and the structures that are superficial and ...
Dental radiographs, commonly known as X-rays, are radiographs used to diagnose hidden dental structures, malignant or benign masses, bone loss, and cavities.. A radiographic image is formed by a controlled burst of X-ray radiation which penetrates oral structures at different levels, depending on varying anatomical densities, before striking the film or sensor.
The study of astronomical objects at the highest energies of X-rays and gamma rays began in the early 1960s. Before then, scientists knew only that the Sun was an intense source in these wavebands. Earth's atmosphere absorbs most X-rays and gamma rays, so rocket flights that could lift scientific payloads above Earth's atmosphere were needed.
Spacecraft, both robotic and crewed, must cope with the high radiation environment of outer space. Radiation emitted by the Sun and other galactic sources, and trapped in radiation "belts" is more dangerous and hundreds of times more intense than radiation sources such as medical X-rays or normal cosmic radiation usually experienced on Earth. [27]
X-rays start at ~0.008 nm and extend across the electromagnetic spectrum to ~8 nm, over which the Earth's atmosphere is opaque.. X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray observation and detection from astronomical objects.
Meanwhile, the Pythagorean astronomical system proposed the Earth and Sun and a counter-Earth rotate around an unseen "Central Fire". Influenced by Pythagoran thinking and Plato, philosophers Eudoxus, Callippus, and Aristotle all developed models of the solar system based on concentric spheres. These required more than one sphere per planet in ...
The set up does not drastically differ for taking X-rays of cultural objects. The radiography of cultural property is the use of radiography to understand intrinsic details about objects. Most commonly this involves X-rays of paintings to reveal underdrawing , pentimenti alterations in the course of painting or by later restorers, and sometimes ...
In the Earth's sky seen in ultraviolet light, most stars would fade in prominence. Some very young massive stars and some very old stars and galaxies, growing hotter and producing higher-energy radiation near their birth or death, would be visible. Clouds of gas and dust would block the vision in many directions along the Milky Way.