Search results
Results from the WOW.Com Content Network
Olbers's paradox says that because the night sky is dark, at least one of these three assumptions must be false. Olbers's paradox , also known as the dark night paradox or Olbers and Cheseaux's paradox , is an argument in astrophysics and physical cosmology that says the darkness of the night sky conflicts with the assumption of an infinite and ...
Olbers' paradox, described by him in 1823 (and then reformulated in 1826), states that the darkness of the night sky conflicts with the supposition of an infinite and eternal static universe. In July 1804, the young Friedrich Wilhelm Bessel contacted Olbers to get his opinion of Bessel's treatise on orbit calculation of Halley's Comet .
Olbers' paradox: Why is the night sky dark if there is an infinity of stars, covering every part of the celestial sphere? GZK paradox : Extreme-energy cosmic rays (like the Oh-My-God particle and several others after it) have been observed that seem to violate the Greisen–Zatsepin–Kuzmin limit , which is a consequence of special relativity .
Brass is an example of an alloy, being a homogeneous mixture of copper and zinc. Another example is steel, which is an alloy of iron with carbon and possibly other metals. The purpose of alloying is to produce desired properties in a metal that naturally lacks them. Brass, for example, is harder than copper and has a more gold-like color.
Homeless Children in 2010: 31,386 11 For the complete Report Card (including sources), please visit: www.HomelessChildrenAmerica.org STATE RANKS (1-50, 1 = best)
1720 – Edmund Halley puts forth an early form of Olbers' paradox (if the universe is infinite, every line of sight would end at a star, thus the night sky would be entirely bright). 1729 – James Bradley discovers the aberration of light , which proved the Earth's motion around the Sun, [ 72 ] and also provides a more accurate method to ...
English: Olbers' Paradox: If stars distributed evenly in the universe, proportions of star surfaces must approximately equal at each distance. If so, we would see a star surface in almost any direction and the darkness of the night sky disappearred.
13P/Olbers, a periodic comet; Heinrich Wilhelm Matthias Olbers was a German astronomer; Olbers (crater), on the Moon; Olbers, a 200 km diameter dark albedo feature on 4 Vesta's surface; Olbers' paradox, evidence for a finite, dynamic universe, based on the luminosity of the night sky