On 31 May 1919, Einstein’s Theory of Relativity was put to the test.
The total eclipse of the Sun has been the subject of scientific interest ever since the time of the Ancient Babylonian astronomers, but of all the thousands of eclipses studied by scientists, the eclipse of 31 May 1919 was the most important. It was able to provide the clinching evidence in favour of one of the most revolutionary ideas in the history of physics, namely Einstein?s theory of general relativity.
Although general relativity was a radically new formulation of gravity, its predictions were largely consistent with Newton?s highly successful theory of gravity. However, Einstein?s theory did make one or two predictions which distinguished it from Newton?s theory, and, if true, these predictions would show that Einstein?s model was closer to reality. For example, Einstein predicted that a gravitational field should bend rays of light much more than was expected by Newton?s theory of gravity. Although the effect was too small to be observed in the laboratory, Einstein calculated that the immense gravity of the massive sun would deflect a ray of light by 1.75 seconds of arc ? less that one thousandth of a degree, but twice as large as the deflection according to Newton, and significant enough to be measured.
Einstein pictured a scenario whereby the straight line of sight between a star and an observer on Earth would be just blocked by the edge of the Sun. Einstein believed that the star would still be visible because gravity would bend the rays of light around the sun and towards the earth. The sighting of a star that should have been blocked by the sun would prove Einstein right, but it is generally to impossible to see starlight that passes close to the Sun, because it is swamped by the brilliance of the sun itself. However, during an eclipse, the Sun is blacked out by the Moon, and under such conditions a gravitationally distorted star should be visible.
General relativity was born in 1915 during the First World War, and as soon as the war ended the Astronomer Royal Sir Frank Dyson began preparing for the next total eclipse, which would occur on 29 May 1919, and which would be an opportunity to test Einstein?s theory. He had already recruited Arthur Eddington, Plumian Professor of Astronomy at Cambridge, to make the observations, a decision that was largely a consequence of Eddington?s pacifist beliefs. The son of devout Quakers, Eddington had nearly spent the war as a conscientious objector peeling potatoes in an army camp, but instead Dyson had arranged for a letter of deferment, which allowed him to carry on his astronomical research. However, in return, Eddington had to promise to make the trek to the island of Principe, off the coast of West Africa, one of the best locations for observing the 1919 eclipse.
The eclipse seemed almost too good to be true. Totality would last for 410 seconds, almost seven minutes, which is extraordinarily long for an eclipse, and which would provide plenty of opportunity for measurements to be taken. Also, the eclipse would occur against the rich background of the Hyades constellation, increasing the likelihood for an appropriately positioned star. However, as the vital day approached a cloud, or rather several, loomed on the horizon. It rained every day for the nineteen days prior to the eclipse, and as the eclipse began on 29 May, the sun was obscured by clouds. For 400 seconds the eclipse was hidden from view, and throughout this period Eddington prayed. Then with only ten seconds of the eclipse remaining, the skies miraculously cleared, and he was able to take just one meaningful photograph.
Eddington compared his eclipse photos with images taken when the sun was not present, and announced that the sun had caused a deflection of roughly 1.61 seconds of arc, a result that was in agreement with Einstein?s prediction, thereby validating the theory of general relativity.
Eddington?s result was hailed as a wondrous piece of science, experimental validation of the greatest intellectual achievement of the of the youthful twentieth century, a sign of optimism in a world that had been torn apart by war. J.P. McEvoy, author of the ?Eclipse?, encapsulated the significance of the announcement: ?A new theory of the universe, the brain-child of a German Jew working in Berlin, had been confirmed by an English Quaker on a small African island.?
Philharmonic Hall
The Philharmonic Hall was a major music hall throughout the 1860s and early 1870s.
The Philharmonic Hall was built by the contractors Holland and Hannen on the site of some former tenements. It opened with a banquet on 7 November 1860. The Hall was the first of many places of entertainment that would be built on this site, culminating in the Islington Empire of 1908.
The Hall was redecorated in 1874 and the building was also renamed the Philharmonic Theatre, with a seating capacity for some 758 people. Alas it was destroyed by fire in September 1882. The Grand Theatre opened on its site in August 1883.
Like its predecessor, the (first) Grand Theatre was destroyed by fire, this time only four years after being built, during the staging of the annual Christmas pantomime on 29 December 1887.
The owners, Holt and Wilmot, immediately set about rebuilding the Theatre with Frank Matcham again doing the redesign. The second Grand Theatre reopened a year later on 1 December 1888 with a production of ’The Still Alarm’.
Despite constructing every available surface out of concrete, this Theatre too, like all its predecessors, was also devastated by fire on 26 February 1900. The fire broke out on a Monday morning when the Theatre had been staging the drama ’Hearts are Trumps’.
The third Grand Theatre was opened on 26 December 1900 with a production of the pantomime ’Robinson Crusoe’. Again the work was carried out under the supervision of Frank Matcham.
In 1908 the Grand Theatre was renamed the Islington Empire, running as a variety theatre by its manager Walter Gibbons. In 1912 the theatre was renamed again to the Islington Palace, run by Charles Guliver.
After being renamed back to the Islington Empire, it was turned over to full time cinema use and was taken over by the Associated British Cinemas chain in 1938.
ABC closed the cinema on the 10 March 1962. The auditorium was demolished and the site used as a car park, leaving only some of the exterior walls and facade still standing. The entrance of the former theatre became the entrance to the car park.
TUM Book Club: Old Covent Garden
The magic of the old Covent Garden Market is evoked through Clive Boursnell’s photographs, taken over the course of numerous visits to Covent Garden in the 1960s and 1970s.
In the late 1960s and early 1970s Clive Boursnell, then a young photographer, shot thousands of photographs of the old Covent Garden, documenting the end of an era before the markets moved out of central London. Boursnell captured these last days of the market over a period of six years, from 1968 until the market’s closure, in a series of beautiful portraits of the feisty life of a city institution.
Queen’s Road Station, Bayswater (c. 1916)
Walter Richard Sickert (1860–1942)
Video: Oyster
Getting around London with Oyster
TUM Dine With Me:fineart:TUM Books
You must log in to post a comment.