Universe Reference Libraries

Page 2 of about 17 Articles
2004-10-19 04:45:41

Multiverse -- The term Multiverse was invented in December 1960, by Andy Nimmo, then vice chairman of the British Interplanetary Society, Scottish Branch, for a talk on the Everett many-worlds interpretation of quantum physics which had been published in 1957, to the branch. This was given in February 1961, and the word with its original definition, "an apparent universe, a multiplicity of...

Quintessence Dark Energy
2004-10-19 04:45:41

Quintessence (Dark Energy) -- Quintessence or dark energy is a hypothetical form of energy postulated to exist in order to explain observations of an accelerating universe. This energy would act like a vacuum pressure, pushing things apart. Other attempts to explain these recent observations involve a non-zero cosmological constant, which has the same effect. Indeed, sometimes...

Cosmological Constant
2004-10-19 04:45:41

Cosmological Constant -- The cosmological constant (usually denoted by the Greek capital letter lambda: Λ) is a value occurring in Einstein's theory of general relativity. The units of Λ are 1/second2; its value is unknown but believed to be positive based on recent observations. The constant is proportional to the energy density of the vacuum ρ, where π is Pi, G is the...

Big Bang
2004-10-19 04:45:41

Big Bang -- The Big Bang theory is the dominant theory in cosmology about the early development and current shape of the universe. According to this theory, the universe expanded rapidly starting 13.7 0.2 billion years ago. Extrapolating the history of the universe backwards using current physical models leads to a gravitational singularity, at which all distances become zero and...

Accelerating Universe
2004-10-19 04:45:41

Accelerating universe -- In the late 1990s, observations of type I supernova produced the unexpected result that the expansion of the universe appears to be accelerating. These observations appear more firm as new data has appeared. This means that the speed with which a distant galaxy recedes from us increases over time. If this trend continues, eventually we won't be able to see any...

2004-10-19 04:45:40

Sirius -- Sirius (α Canis Major, also known as the Dog Star) is the brightest star (-1.46m) in the night sky and can be seen from every inhabited region of the Earth's surface. At a distance of 8.6 light years, Sirius is also one of the nearest stars to Earth. It is a main sequence star of spectral type A0 or A1 and has a mass about 2.4 times that of the Sun. Sirius has a white dwarf...

Rosette Nebula
2004-10-19 04:45:40

Rosette Nebula -- Discovered by John Flamsteed about 1690. The Rosetta Nebula is a vast cloud of dust and gas, extending over an area of more than 1 degree across, or about 5 times the area covered by the full moon. Its parts have been assigned different NGC numbers: 2237, 2238, 2239, and 2246. Within the nebula, open star cluster NGC 2244 is situated, consisted of the young stars which...

Word of the Day
  • In the month which preceded the present; in the last month, as distinguished from the current or present month and all others.
  • In the month which preceded the present; in the last month, as distinguished from the current or present month and all others.
The word 'ultimo' comes from the Latin phrase 'ultimo mense', 'in the last month'.