The open philosophy of most wikis, allowing anyone to edit content, does not ensure that every editor is well-meaning. Vandalism can be a major problem. In larger wiki sites, such as those run by the Wikimedia Foundation, vandalism can go unnoticed for a period of time. Wikis by their very nature are susceptible to intentional disruption, known as ""trolling"". Wikis tend to take a soft security approach to the problem of vandalism; making damage easy to undo rather than attempting to prevent damage. Larger wikis often employ sophisticated methods, such as bots that automatically identify and revert vandalism and JavaScript enhancements that show characters that have been added in each edit. In this way vandalism can be limited to just ""minor vandalism"" or ""sneaky vandalism"", where the characters added/eliminated are so few that bots do not identify them and users do not pay much attention to them.

For some time it was thought that the number of neutrinos produced by the nuclear reactions in the Sun was only one third of the number predicted by theory, a result that was termed the solar neutrino problem. Several neutrino observatories were created including the Sudbury Neutrino Observatory to try and measure the amount of neutrinos given off by the Sun. From these observatories and experiments it was recently found that neutrinos had rest mass, and could therefore transform into harder-to-detect varieties of neutrinos while en route from the Sun to Earth; thus measurement and theory were reconciled.

Steuer, Kenneth։ ‘Pursuit of an 'Unparalleled Opportunity' - The American YMCA and Prisoner of War Diplomacy among the Central Power Nations during World War I, 1914-1923’, Kalamazoo (Michigan), 2008.

City Library: The Médiathèque de l’Europe was inaugurated in October 2006. In it can be found CDs, books (novels, comics, documentaries, magazines etc.), DVDs, music scores…

If a player kicks the ball out of play at their end of the field, the other team kicks the ball back into play from the corner (a corner kick);

4000 Years of Algebra, lecture by Robin Wilson, at Gresham College, October 17, 2007 (available for MP3 and MP4 download, as well as a text file).

Each of these power quality problems has a different cause. Some problems are a result of the shared infrastructure. For example, a fault on the network may cause a dip that will affect some customers; the higher the level of the fault, the greater the number affected. A problem on one customer’s site may cause a transient that affects all other customers on the same subsystem. Problems, such as harmonics, arise within the customer’s own installation and may propagate onto the network and affect other customers. Harmonic problems can be dealt with by a combination of good design practice and well proven reduction equipment.