- Radium (Wikipedia)
Radium is a chemical element; it has symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are radioactive, the most stable isotope being radium-226 with a half-life of 1,600 years. When radium decays, it emits ionizing radiation as a by-product, which can excite fluorescent chemicals and cause radioluminescence. For this property, it was widely used in self-luminous paints following its discovery. Of the radioactive elements that occur in quantity, radium is considered particularly toxic, and it is carcinogenic due to the radioactivity of both it and its immediate decay product radon as well as its tendency to accumulate in the bones.
- Star Tales - Sculptor (ianridpath.com)
A faint constellation south of Cetus and Aquarius, invented by the French astronomer Nicolas Louis de Lacaille during his mapping of the southern skies in 1751–52. His original name for it, given on his planisphere of 1756, was l’Atelier du Sculpteur, the sculptor’s studio, although in the accompanying star catalogue he spelled (or mis-spelled) the first part of the name as ‘attelier’. As described by Lacaille, it consisted of a carved head on a three-legged table, with the artist’s mallet and a chisel on a block of marble next to it (although his illustration actually showed two chisels). On Lacaille’s 1763 planisphere the title was Latinized to Apparatus Sculptoris.
- Sculptor (constellation) (Wikipedia)
Sculptor is a small and faint constellation in the southern sky. It represents a sculptor. It was introduced by Nicolas Louis de Lacaille in the 18th century. He originally named it Apparatus Sculptoris (the sculptor’s studio), but the name was later shortened.
