Einstein's prediction of gravitational waves is best understood through comparison with electromagnetic waves, which were predicted by Maxwell in 1864 and discovered by Hertz 22 years later. We now know that light is one tiny band of the enormous electromagnetic spectrum. Electromagnetic waves are waves of electrical energy which give us our sense of 'vision' with which to comprehend the universe. The discovery of electromagnetic waves set the foundation for the electronic revolution of the 20th century. This not only revolutionised our lives, but also our understanding of the universe, as astronomers gradually harnessed the electromagnetic spectrum, first with visible light, and then by radio waves, microwaves, x-rays and gamma-rays. Each new part of the spectrum provided dramatic new insights into the universe, while driving the development of ever more sophisticated technology. Einstein predicted the existence of gravitational waves in 1916, but the world had to wait until 1993, when Joseph Taylor and Russell Hulse were awarded the Nobel Prize for an indirect proof of their existence. They proved that the loss of energy from a pair of neutron stars was due to the production of gravitational waves. Gravitational waves are akin to sound waves, but they travel through space at the speed of light. When black holes are formed they can produce more gravity wave power than the light power of all the stars in the universe put together! And yet gravitational waves pass through the earth as if it was not there. Even when their energy is enormous, they make infinitesimal vibrations, much smaller than the size of an atom. Over the last 30 years, scientists have created increasingly sensitive detectors with the hope of detecting these signals from space. At last, we are at a threshold where detectors have been designed that are certain to detect known signals from coalescing pairs of superdense neutron stars and black holes. It is likely that gravitational waves will be detected within the next decade and once detected, the exploration of this new spectrum offers the most exciting frontier of physics today.