The glass harmonica, also known as the glass armonica, glass harmonium, bowl organ, hydrocrystalophone, or simply the armonica or harmonica (derived from ἁρμονία, harmonia, the Greek word for harmony), is a type of musical instrument that uses a series of glass bowls or goblets graduated in size to produce musical tones by means of friction (instruments of this …

Theory of Colours (German: Zur Farbenlehre) is a book by Johann Wolfgang von Goethe about the poet's views on the nature of colours and how these are perceived by humans. It was published in German in 1810 and in English in 1840. The book contains detailed descriptions of phenomena such as coloured shadows, refraction, and chromatic aberration.. The work …

The streetlight effect, or the drunkard's search principle, is a type of observational bias that occurs when people only search for something where it is easiest to look. Both names refer to a well-known joke: A policeman sees a drunk man searching for something under a streetlight and asks what the drunk has lost.

Maximilien François Marie Isidore de Robespierre (French: [maksimiljɛ̃ ʁɔbɛspjɛʁ]; 6 May 1758 – 28 July 1794) was a French lawyer and statesman who became one of the best-known, influential and controversial figures of the French Revolution.As a member of the Estates-General, the Constituent Assembly, and the Jacobin Club, he campaigned for universal manhood suffrage, …

Perception (from Latin perceptio 'gathering, receiving') is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system, which in turn result from physical or chemical stimulation of the sensory system.

Medievalism is a system of belief and practice inspired by the Middle Ages of Europe, or by devotion to elements of that period, which have been expressed in areas such as architecture, literature, music, art, philosophy, scholarship, and various vehicles of popular culture. Since the 17th century, a variety of movements have used the medieval period as a model or inspiration …

Washington's Farewell Address is a letter written by American President George Washington as a valedictory to "friends and fellow-citizens" after 20 years of public service to the United States. He wrote it near the end of his second term of presidency before retiring to his home at Mount Vernon in Virginia.. The letter was first published as The Address of Gen. Washington to …

The Road to Enlightenment. Littering a dark and dreary road lay the past relics of browser-specific tags, incompatible DOMs, broken CSS support, and abandoned browsers. We must clear the mind of the past. Web enlightenment has been achieved thanks to the tireless efforts of folk like the W3C, WaSP, and the major browser creators.

The Irish (Irish: Muintir na hÉireann or Na hÉireannaigh) are an ethnic group and nation native to the island of Ireland, who share a common history and culture.There have been humans in Ireland for about 33,000 years, and it has been continually inhabited for more than 10,000 years (see Prehistoric Ireland).For most of Ireland's recorded history, the Irish have been primarily a …

Rodelinda, regina de' Longobardi (HWV 19) is an opera seria in three acts composed for the first Royal Academy of Music by George Frideric Handel. The libretto is by Nicola Francesco Haym, based on an earlier libretto by Antonio Salvi. Rodelinda has long been regarded as one of Handel's greatest works.

The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going from hand production methods to machines, new chemical manufacturing and iron production processes, the increasing use of steam power and …

Antecedents Enlightenment thinkers. During the Age of Enlightenment (an era from the 1650s to the 1780s), concepts of monogenism and polygenism became popular, though they would only be systematized epistemologically during the 19th century. Monogenism contends that all races have a single origin, while polygenism is the idea that each race has a separate origin.

Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths).. In physics, the term "light" may …

Thomas Hobbes (/ h ɒ b z / HOBZ; 5/15 April 1588 – 4/14 December 1679) was an English philosopher, considered to be one of the founders of modern political philosophy. Hobbes is best known for his 1651 book Leviathan, in which he expounds an influential formulation of social contract theory. In addition to political philosophy, Hobbes contributed to a diverse array of …