Columbia Encyclopedia

Search results

500 results found

Eudoxus of Cnidus

(Encyclopedia)Eudoxus of Cnidus yo͞odŏkˈsəs, nīˈdəs [key], 408?–355? b.c., Greek astronomer, mathematician, and physician. From the accounts of various ancient writers, he appears to have studied with Plat...

Pegasus, in astronomy

(Encyclopedia)Pegasus pĕgˈəsəs [key], in astronomy, northern constellation lying SW of Andromeda and SE of Cygnus. It is named for the mythological winged horse Pegasus. The constellation is easily recognized b...

planet

(Encyclopedia)planet [Gr.,=wanderer], a large nonluminous body of rock, gas, or ice that orbits the sun or another star, has a rounded shape due to gravity, and has cleared its orbit of smaller objects. The term, o...

Neptune, in astronomy

(Encyclopedia)Neptune, in astronomy, 8th planet from the sun at a mean distance of about 2.8 billion mi (4.5 billion km) with an orbit lying between those of Uranus and the dwarf planet Pluto; its period of revolut...

calendar

(Encyclopedia)calendar [Lat., from Kalends], system of reckoning time for the practical purpose of recording past events and calculating dates for future plans. The calendar is based on noting ordinary and easily o...

De la Rue, Warren

(Encyclopedia)De la Rue, Warren dĕlˈəro͞o, dĕləro͞oˈ [key], 1815–89, British scientist and inventor. Especially noted as an astronomer, he was a pioneer in celestial photography. He adapted the wet-plate ...

Borschberg, André

(Encyclopedia)Borschberg, André, 1952–, Swiss engineer, businessman, and pilot. With Bertrand Piccard (see under Piccard, Auguste) he founded Solar Impulse to develop a solar-powered plane capable of circumnavig...

heating

(Encyclopedia)CE5 Typical warm-air heating system heating, means of making a building comfortably warm relative to a colder outside temperature. Old, primitive methods of heating a building or a room within it ...

gegenschein

(Encyclopedia)gegenschein gāˈgənshīnˌ [key] or counterglow, a slight brightening of the night sky in the region of the zodiac directly opposite the sun, i.e., 180° from the sun. Discovered by the Danish astro...

terrestrial planet

(Encyclopedia)terrestrial planet, the earth or a planet that resembles the earth in its physical characteristics. The terrestrial planets in the solar system are the earth, Mercury, Venus, and Mars. These planets a...