LIGO scientists estimate the black holes were 29 and 36 times the mass of the Sun, and the event took place 1.3 billion years ago. Similar gravitational waves have probably passed through the Earth before, but this time, someone was watching.

"In a landmark discovery for physics and astronomy, scientists yesterday said they have glimpsed the first direct evidence of gravitational waves, ripples in the fabric of space-time that Albert Einstein predicted a century ago". Since gravity is a weak force, Einstein predicted it would be nearly impossible to detect these ripples, even as they passed through people and objects on Earth.

Physicist Kip Thorne said: "With this discovery, we humans are embarking on a marvelous new quest: the quest to explore the warped side of the universe-objects and phenomena that are made from warped space-time".

Albert Einstein's general theory of relativity has been proved right after more than a hundred years. Importantly, last week's announcement is expected to add momentum to the efforts of Indian scientists hoping to set up the first Ligo-like device in India. "We will be able to measure the rate the universe is expanding, or how much dark energy there is in the universe to extraordinary precision - far, far greater than we can do today".

"That's the chirp we've been looking for", said Louisiana State University physicist Gabriela Gonzalez, scientific spokeswoman for the LIGO team. Now, the detection of these undulations has changed how we see the universe.

The new facilities will help astrophysicists pinpoint the precise location of cataclysmic events such as black hole mergers and supernovas. MIT astrophysicist Nergis Mavalvala said that they have opened a new door for astronomy.

"And when we hear the universe, we will learn about the secret life of black holes - their birth, their death, their marriage, their feeding".

Scientists mostly use the word "hear" when describing gravitational waves, and the data does, in fact, arrive in audio form. "We will not only understand it, we will "see" it. It's the most fascinating thing I can imagine". Discovery of gravitational waves would confirm their existence.