The history of timekeeping devices dates back to ancient civilizations
observing astronomical bodies. Sundials and water clocks originated in
ancient Egypt, while incense clocks were used in China. Mechanical
clocks were developed in medieval Europe after the invention of the
bell-striking alarm; Henry de Vick built a mechanical clock around 1360
that was the basis for improvements in timekeeping for the next 300
years. The mainspring, invented in the 15th century, allowed small
clocks to be built. Leonardo da Vinci produced the earliest drawings of
a pendulum. The pendulum clock, designed by Christiaan Huygens in 1656,
was more accurate than other mechanical timekeepers. The electric clock,
invented in 1840, controlled the most accurate pendulum clocks until the
1940s, when quartz timers became the basis for precise measurement of
time and frequency. Atomic clocks are the most accurate timekeeping
devices in practical use today and are used to calibrate timekeeping
instruments.
Read more: <https://en.wikipedia.org/wiki/History_of_timekeeping_devices>
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Today's selected anniversaries:
1773:
The hymn "Amazing Grace" was probably first used in a prayer
meeting in Olney, England, without the music familiar to modern
listeners.
<https://en.wikipedia.org/wiki/Amazing_Grace>
1892:
The immigration station on Ellis Island in New York Harbor
opened, and would process almost 12 million immigrants to the United
States over the course of its existence.
<https://en.wikipedia.org/wiki/Ellis_Island>
1928:
Joseph Stalin's personal secretary, Boris Bazhanov, crossed the
Iranian border and defected from the Soviet Union.
<https://en.wikipedia.org/wiki/Boris_Bazhanov>
1998:
Argentinian physicist Juan Maldacena published a landmark paper
initiating the study of AdS/CFT correspondence, which links string
theory and quantum gravity.
<https://en.wikipedia.org/wiki/AdS/CFT_correspondence>
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Wiktionary's word of the day:
qualtagh:
(Isle of Man) The first person one encounters, either after leaving
one's home or (sometimes) outside one's home, especially on New Year's
Day; a first-foot.
<https://en.wiktionary.org/wiki/qualtagh>
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Wikiquote quote of the day:
Love — caritas — is an extraordinary force which leads people
to opt for courageous and generous engagement in the field of justice
and peace. It is a force that has its origin in God, Eternal Love and
Absolute Truth. Each person finds his good by adherence to God's plan
for him, in order to realize it fully: in this plan, he finds his truth,
and through adherence to this truth he becomes free … To defend the
truth, to articulate it with humility and conviction, and to bear
witness to it in life are therefore exacting and indispensable forms of
charity.
--Pope Benedict XVI
<https://en.wikiquote.org/wiki/Pope_Benedict_XVI>