This article is part of FT Globetrotter’s London
For a navigator, time and distance are tightly connected. The ground turns 360 degrees to its axis every 24 hours. This means that a person standing at the equator travels to the east a scale of length, approximately 111 km, every four minutes. People have long realized that the passage of the sun, stars and other bodies beyond the sky caused by the represented rotation – with careful observation and some neat calculations – a reliable method for both time and for determining a location on the surface of the earth.
Encouraged by my father -in -law, who was an Air Force navigator, I learned how to navigate in 1999 as part of a long dream to train for my private pilot license. Since then, I have been fascinated by the diverse mixture of geography, astronomy, mechanics, mathematics and history in the heart of navigation.
Although today the Royal Greenwich Observatory, south-east of London, is an excellent museum, for nearly 300 years the site was a center for astronomical and floating observations and research. Its beautiful buildings, some of them I- and II grades listed and one, Flagsteed House, designed by Sir Christopher Wren, sit on top of a hill in Greenwich Park commanding beautiful impeding images as well as night sky- Greenwich municipality, thanhams, Wharf Canary and West. It owes its very existence for a pressing 17th-century need for navigation research. King Charles II founded it in 1675 with a brief summary to find a practical method of adjusting the length for accurate navigation, as naval power was becoming crucial to national success. The walk described below gives an overview of the history of navigation and time of time and the main role of observation in it.
Meridian
A good place to begin with is the Meridian Observatory, a collection of rooms built between the 17th and 19th centuries to house instruments, with large windows and opening roofs to observe the sky along the meridians – imaginary lines on the surface of the earth that connect the northern and southern poles.
Some of the beautiful on -screen instruments are linked as they were initially with meridians bearing the names of the Royal astronomers who placed them: Flagteed (1689), Halley (1725), Bradley (1750) and Airy (1851). They used telescopes to plan positions of heavenly bodies in the sky in the same way that cities are drawn on the earth’s surface maps. The mural quadrant consisting of a telescope mounted on a metal trimester circle that gives the device its name and the telescope installed in the Bradley meridian are delightful examples of 18th -century scientific instruments
Observations of his telescope were precisely observed by microscopes in transit support blocks, plus they were time from a reliable hour. Prior to the International Conference of the International Meridia of 1884, there was no agreement agreed with Meridian Prime Minister – a landing line of zero degrees – with many countries and organizations using a variety of meridians for the purpose. The conference decided that the meridian passing through the airy transit must become the main meridian of the Earth from then on. While Meridian was in Greenwich, GMT at the same time became a standard world time reference. However, in 1988, IERER (International Land Rotation Service) Meridian, based on a new group of coordinates calculated from satellite data, entered into action. Differences in the methods for regulating satellites and positions of the transit circle imply that the meridian Iers is actually 102.5 meters east of Airy, though still based on his main meridian. You can demonstrate this and impress your friends by placing a smartphone with a cartography app in the prime minister’s meridian and you will notice that the length given is not exactly zero.
Lit
You then cross the observation yard – stopping, as every visitor does, stay in the main meridian with one foot in the eastern and western hemispheres – and enter the Flagsteed house, the oldest building of the museum. It is an extremely practical design. The ground floor contains former livelihoods for astronomers Royal, 10 of whom lived there for nearly 300 years until 1948. His rooms give a mirror in their lives, with objects such as a visible teaching paint presented to George Airy to advise the city of Chester at the heights of the decease . ‘
Above the living neighborhoods is the Octagon room, a rare chance to see an original interior designed by Christopher Wren. Large windows designed to give unhindered views of the sky and, inadvertently, local areas, make a sublime, bright space and high ceilings allowed the long pendulum needed for the accuracy of room hours. Beautiful though it is, the room is flawed. As a measure of cost savings, it was built on the foundations of the previous building, which means it was not compatible with a meridian, making it frustrating impractical for observations.
Return to the first floor, another gallery explains the role of observation in the problem of length, finding a reliable and practical way of determining an east-west location at sea to enable safe and efficient maritime travel. Two rival theories competed to solve it, one involving the observation of the celestial bodies and the other depending on the correct retention of time at sea. Both had their supporters, advantages and shortcomings.
Personally, the highlights of this gallery, and in fact the museum, are John Harrison’s hours (1693–1776), one of my heroes. Harrison was a capable and extremely determined schedule creator who devoted years to solve the length with his amazing schedules in pursuit of the wealth offered by the British Government’s length price, which he finally won. The four on-screen mechanisms are as smart as they are beautiful, offsetting all the bad things that a dangerous 18th-century ocean journey could throw in them.
Another floor below is the Koha and Greenwich Gallery, where exhibitions illustrate the modern time of time and the role the observatory has played in creating increasingly accurate hours. Tracking accuracy is essential here, and intriguing schedules in the show illustrate how regular oscillation of pendulum watches was repealed by electronic devices and other equipment. One hour’s signals were broadcast by the Telegraph to provide GMT for Britain’s railways, creating standard time across the country and replacing the 19th-century chaotic system, which each city placed its hours near the noon sun-for example, pre-GMT, the hours in Bristol were 10 minutes after those in London. Another hour on screen was the source from 1924 to 1949 of the time signals used by the BBC as the basis of its “six PI” hours.
Amazing watches based on the frequencies of atom components (1949) and later in GPS signals from space satellites (1993) brought further accuracy. The developing quantum clock will now eventually evaluate their accuracy in billions of years.
The gallery of time and society and the great equatorial telescope
Going back to the yard, above the Meridian Observatory is the gallery of time and society. Civilization goes in accurate time, and exhibits here the chronicles of inventions that achieved it: devices that benefited from heavenly movements such as exquisite rule, astrolabes and quadrants; mechanical hours with intricate escape and pendulum; and modern Electronic and GPS Timekeepers. One remembers what time is the essential time, whether it is in a London transport time recorder, a second hour of World War II “Zigzag” used to make ships change their course to avoid enemy attacks or a Russian hour for time movements in chess matches.
The progress of a spiral ladder leads you to the large equatorial telescope of 1893, placed in the onion cubes that makes the observatory a special landmark on the Greenwich horizon. Telescopes The largest refractory telescope in the UK and still in use by the Museum for public astronomy sessions. At the original view, it seems to be compatible with a strange strange angle, but this stretch means that the telescope moves parallel to the equator so that the stars can be easily tracked throughout the sky while slowly progressing. Mounting the telescope in a frame originally created for a narrow instrument adds to its strange appearance. The images are fraudulent, however, and the exact observations of the telescope were useful in calculating the masses of double stars rotating around each other.
When the time is, don’t forget to check your clock at the Shepherd 1852 gate clock as you leave. The first public hour to display Greenwich’s average time (though with a 24-hour face) is still very accurate and a recent reminder of the importance of Greenwich to help us know our time and country.
Have you visited the Royal Observatory of London Greenwich? Tell us in the comments below. AND Follow FT Globetrotter on Instagram at @Ftglobetrotter
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