New paper suggests that the hotly contested physics thesis, which involves the existence of six ‘extra dimensions’, may be settled by cutting-edge laser detectors
String theory makes the grand promise of weaving together all of physics into a single sublime framework. The only downside is that scientists have yet to find any experimental proof that it is right – and critics question whether its predictions are even testable.
Now, a new paper has claimed that gravitational wave measurements could hold the key to whether string theory is destined to fulfil its lofty goals or be consigned to the dustbin of discarded ideas. The study suggests that the first observable evidence for the existence of extra dimensions, one of string theory’s predictions, could be hidden within the ripples of gravitational waves.
“It would be amazing because general relativity and Einstein do not predict this at all,” said David Andriot, a physicist at the Max Planck Institute for Gravitational Physics in Potsdam and lead author of the study.
The crux of string theory – although there are many competing versions – is that all particles can be viewed as one-dimensional strings on which the fundamental forces of nature (gravity, electromagnetism and so on) act as different modes of vibration. For reasons better explained in maths than words, the framework also requires there to be at least six extra spatial dimensions, in addition to time and the three spatial ones of everyday life.
Scientists, notably those working at the Large Hadron Collider, have looked for energy vanishing into these hypothetical extra dimensions, but so far efforts have been inconclusive. One possibility is that the dimensions are coiled up so tightly that they are imperceptible; another is that they are not there at all.