Astronomy experiments could soon test an idea developed by Albert Einstein almost exactly a century ago, scientists say.
Tests using advanced technology could resolve a longstanding puzzle over what is driving the accelerated expansion of the Universe.
Researchers have long sought to determine how the Universe's accelerated expansion is being driven. Calculations in a new study could help to explain whether dark energy- as required by Einstein's theory of general relativity - or a revised theory of gravity are responsible.
Einstein's theory, which describes gravity as distortions of space and time, included a mathematical element known as a Cosmological Constant. Einstein originally introduced it to explain a static universe, but discarded his mathematical factor as a blunder after it was discovered that our Universe is expanding.
Research carried out two decades ago, however, showed that this expansion is accelerating, which suggests that Einstein's Constant may still have a part to play in accounting for dark energy. Without dark energy, the acceleration implies a failure of Einstein's theory of gravity across the largest distances in our Universe.
Scientists from the University of Edinburgh have discovered that the puzzle could be resolved by determining the speed of gravity in the cosmos from a study of gravitational waves -space-time ripples propagating through the universe.
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