Berlin. 100 years ago, Albert Einstein revolutionized physics with his theory of general relativity, although it was not until much later that it was discovered its true scope.
Who today turns the GPS finds a way to get destination thanks to, among others, Einstein, whose theory of relativity allowed the accuracy provided by the satellite navigation. However, this German scientist could not imagine this handy application when it proposed the core of it on November 25, 1915 before the Prussian Academy of Sciences in Berlin.
The scope of work of this genius Science, however, was much deeper. It revolutionized the way we see the world, although this was not clear from the start
“It was a millennial milestone of science which took place in Berlin,” says the Professor Hermann Nicolai, director of the Albert Einstein Institute of the Max Planck Society in the city of Potsdam. “But only after several decades it became clear what kind of achievement that was.”
Ten years earlier, Einstein had proposed his theory of special relativity, which holds that space and time can not be measuring separately. Einstein recognized that simultaneity is a relative quality, which depends on the observer.
Two events occurring in different areas may seem simultaneous and consecutive to one another. Only one place is apparent simultaneity of two events.
The special relativity leads to the existence of a fourth spatial dimension through interaction of the three spatial dimensions and time, which thus lost its status absolute measure.
In his theory of general relativity, Einstein added gravity field. The theory argues that space-time is warped by mass. This effect is greater the larger the mass.
“It was a paradigm shift,” explains Nicolai. “The claim is that gravity is a consequence of the curvature of the geometry of space-time.” According to the theory, light deviates measurably due to this curvature when it passes in front of a large mass such as the sun. This proposition made Einstein famous coup four years later.
British Sir Arthur Eddington in 1919 sent two expeditions to observe a solar eclipse, organized by the Royal Astronomical Society (RAS). During that eclipse expeditions measured the positions of stars near the sun darkened. And indeed, positions varied as Einstein had predicted.
“It was a spectacular success, which put Einstein on the cover of the world press,” says Nicolai. “The stars are not where you appear to be,” he wrote at the time for example the New York Times. “But do not worry”.
The first experimental confirmation of the theory of general relativity shook the entire “establishment” scientist. Today, astronomers use this effect as a natural telescope, because the masses of the universe, like a galaxy can bend light from objects that are behind, distant, and increase as a magnifying glass. Astronomers call gravitational lensing.
But after the initial success, there was silence for some time. “The theory disappeared for 20 to 30 years of physical focus, because the effects are so small that many of them can only be measured with the new devices available,” said Nicolai.
For example, too clocks run slower when they are next to a gravitational field. “This is so extreme that time almost stopped next to a black hole,” he explains. However, in the gravitational field of the Earth this effect is so small that on a day to day do not notice. But change is essential for syncing and navigation satellites must be corrected, otherwise the positions are not correct.
“In the 60s and 70s the theory of general relativity came to a foreground, “writes science historian Alexander Blum, the Max Planck Institute. The reason was, among other things, the discovery of exotic celestial objects, very distant, with particular characteristics could explain Einstein’s theory. For example black holes and the fact that its huge gravitational field does not reflect light.
“The researchers had addressed this theory and black holes became superstars physical medium century after the triumph of Einstein, including Britain’s Stephen Hawking, “writes Blum.
The Big Bang, black holes, the constant expansion of the universe can be explained by the theory of general relativity.
“This whole modern cosmology is based on Einstein’s equations,” says Nicolai. The theory has become a cornerstone of modern physics. “Today there are really only two basic physical theories: quantum theory and general relativity”
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