• 460–370 BC) believed that the saturation of the Earth with water caused them; Anaximenes (c. 585–c. 525 BC) believed they were the result of massive pieces of the Earth falling into the cavernous hollows due to drying; and Aristotle (384–322 BC) believed they were caused by instability of vapor (pneuma) caused by the drying of the moist Earth by the Sun's rays.
  • Wikipedia: Zhang Heng
  • A recent theory claims that there are magnetic instabilities in the core of the Sun that cause fluctuations with periods of either 41,000 or 100,000 years.
  • Wikipedia: Sun
  • Although local traditions generally help protect lemurs and their forests, illegal logging, widespread poverty, and political instability hinder and undermine conservation efforts.
  • Wikipedia: Lemur
  • Although the state's GDP has risen significantly since the 1990s, West Bengal has remained affected by political instability and bad governance.
  • Wikipedia: West Bengal
  • As nuncio during the 1920s, he had made unsuccessful attempts to obtain German agreement for such a treaty, and between 1930 and 1933 he attempted to initiate negotiations with representatives of successive German governments, but the opposition of Protestant and Socialist parties, the instability of national governments and the care of the individual states to guard their autonomy thwarted this aim.
  • Wikipedia: Pope Pius XII
  • At very low metallicity, stars of around 140–250 solar masses will reach core collapse by pair instability while they still have a hydrogen atmosphere and an oxygen core and the result will be a supernova with type II characteristics but a very large mass of ejected Ni56 and high luminosity.
  • Wikipedia: Supernova
  • Due to its instability and rarity, there are no commercial applications for francium.
  • Wikipedia: Francium
  • During the early years of the Republic, endemic struggles for power between military leaders caused political instability.
  • Wikipedia: Peru
  • Finally the Queen's instability and religious mania degenerated into complete insanity.
  • Wikipedia: Queluz National Palace
  • He was mentally ill and had gone to numerous clerics for assistance in overcoming this instability.
  • Wikipedia: Wail al-Shehri
  • Her father endured a series of failed entrepreneurial ventures and the instability caused her mother to move them abruptly to the Trefethen family house in Taunton, Massachusetts.
  • Wikipedia: Marjory Stoneman Douglas
  • However, their heavy hammerblow at speed meant that they were prone to rough riding and instability.
  • Wikipedia: LSWR N15 class
  • However, Walpole commanded a substantial majority in Parliament and George II had little choice but to retain him or risk ministerial instability.
  • Wikipedia: George I of Great Britain
  • Illegal logging has been facilitated by insufficient governance, unclear forest regulation, and undermined judicial control while the exportation of the acquired logs (in 1992, 2006, and 2009–2010) has been permitted by government decrees that either precede elections or are issued during periods of political instability.
  • Wikipedia: Marojejy National Park
  • In the 1830s, due to the instability of the Regency, European immigration ground to a halt, only recovering after Pedro II took the reins of government and the country entered a period of peace and prosperity.
  • Wikipedia: Empire of Brazil
  • Its representative parliamentary monarchy also stood in stark contrast to the mix of dictatorships and instability endemic in the other nations of South America during this period.
  • Wikipedia: Pedro II of Brazil
  • Khanh said the instability was due to troublemaking by members and supporters of the Catholic-aligned Dai Viet Quoc Dan Dang (Nationalist Party of Greater Vietnam), whom he accused of putting partisan plotting ahead of the national interest.
  • Wikipedia: September 1964 South Vietnamese coup attempt
  • Luongo's arrival in Vancouver ended a seven-and-a-half-year period of instability for Canucks netminding, with a total of 18 goaltenders having played for the club since Kirk McLean's departure in 1998.
  • Wikipedia: Roberto Luongo
  • Nonlinear optical processes are another active research area, with topics such as two-photon absorption, self-phase modulation, modulational instability and optical parametric oscillators.
  • Wikipedia: Photon
  • One is that the ice giants were not created by core accretion but from instabilities within the original protoplanetary disc, and later had their atmospheres blasted away by radiation from a nearby massive OB star.
  • Wikipedia: Neptune
  • Other classes of unstable main-sequence stars, like beta Cephei variables, are unrelated to this instability strip.
  • Wikipedia: Main sequence
  • Playford inherited a minority government and many independents to deal with, and instability was expected; Playford was seen as a transitional leader.
  • Wikipedia: Thomas Playford IV
  • Postural instability is typical in the late stages of the disease, leading to impaired balance and frequent falls, and secondarily to bone fractures.
  • Wikipedia: Parkinson's disease
  • Rocky planets, which have managed to coalesce, settle eventually into more or less stable orbits, explaining why planetary systems are generally packed to the limit; or, in other words, why they always appear to be at the brink of instability.
  • Wikipedia: Nebular hypothesis
  • Some accounts claim that he showed signs of mental instability towards the end of his life, although less extreme than his father.
  • Wikipedia: George IV of the United Kingdom
  • Spring and fall experience peaks of activity as those are the seasons when stronger winds, wind shear, and atmospheric instability are present.
  • Wikipedia: Tornado
  • Stream bank instability and siltation are common, and landslides deter urban development at higher elevations.
  • Wikipedia: Forest Park (Portland, Oregon)
  • Such a plan, he wrote, would end the political instability and reduce the large number of smaller parties.
  • Wikipedia: George I of Greece
  • Taking advantage of instability in the kingdom of Kent to establish himself as overlord, Offa was also in control of Sussex by 771, though his authority did not remain unchallenged in either territory.
  • Wikipedia: Offa of Mercia