iridium – מילון אנגלי-אנגלי
iridium
n.
precious metallic element of the platinum group (Chemistry); modern satellite communications system that enables mobile telephone communications everywhere in the world (Cellular Communication)
Iridium
Iridium is a
chemical element with symbol
Ir and
atomic number 77. A very hard, brittle, silvery-white
transition metal of the
platinum group, iridium is generally credited with being the second densest element (after
osmium) based on measured density, although calculations involving the space lattices of the elements show that iridium is denser. It is also the most
corrosion-resistant metal, even at temperatures as high as 2000 °C. Although only certain molten salts and
halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.
Iridium satellite constellation
The
Iridium satellite constellation is a
satellite constellation providing voice and data
coverage to
satellite phones, pagers and integrated transceivers over Earth's entire surface.
Iridium Communications owns and operates the constellation and sells equipment and access to its services. It was originally conceived by Bary Bertiger, Dr. Ray Leopold and Ken Peterson in late 1987 (and protected by patents by Motorola in their names in 1988) and then developed by Motorola on a
fixed-price contract from July 29, 1993 to November 1, 1998 when the system became operational and commercially available.
iridium
Noun
1. a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium
(synonym) Ir, atomic number 77
(hypernym) metallic element, metal
Iridium (das)
n.
iridium, precious metallic element of the platinum group (Chemistry)
iridium
nm.
iridium, precious metallic element of the platinum group (Chemistry); modern satellite communications system that enables mobile telephone communications everywhere in the world (Cellular Communication)
