In a world first, scientists have directly observed proof that gravitational waves exist, a discovery that is likely to dramatically deepen our understanding of the universe.

A team of researchers from the California Institute of Technology, the Massachusetts Institute of Technology and the LIGO Scientific Collaboration announced the discovery on Friday morning (AEDT) of these ripples in the fabric of space-time.

The gravitational waves were seen emanating from a collision and merger of two black holes, the researchers told a press conference in the US. They were observed in September 2015, but the collision actually occurred 1.5 billion years ago.

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“We’re getting a signal which arrives at Earth, and we can put it on a speaker, and we can hear these black holes go, ‘Whoop.’ There’s a very visceral connection to this observation,” MIT physicist Matthew Evans said.

LIGO director David Reitze makes the announcement in Washington, DC. Photo: Getty

Famed theoretical physicist Albert Einstein hypothesised that gravitational waves existed as an outgrowth of his seminal theory of relativity. It is the last of his theories to be proven correct.

“Gravitational waves are literally ripples in the curvature of space-time that are caused by collisions of heavy and compact objects like black holes and neutron stars,” Dr Abhay Ashtekar, director of Penn State University’s Institute for Gravitation and the Cosmos, said before the announcement.

The discovery will allow scientists to gain an unprecedented and intimate look at moments like the Big Bang, and discover new information about space we never knew.

“We are really witnessing the opening of a new tool for doing astronomy,” MIT astrophysicist Nergis Mavalvala told the press conference.

Scientists observed the waves using two enormous laser instruments in the United States known as the Laser Interferometer Gravitational-Wave Observatory (LIGO), as well as another in Italy.

(Click on the owl to read how the lasers detect gravitational waves  )

Australian researchers assisted in the discovery.

What are gravitational waves?

Einstein thought this day would never come. Photo: Getty

Gravitational waves occur when objects with strong gravity accelerate.

As the objects accelerate, ripples of space move away at the speed of light.

Gravity is the curvature of space and time, according to Einstein’s theory of relativity.

A greater deformation of gravity will occur the stronger the object’s gravity is.

These waves are actual waves in space, described as the rhythmic stretching and squeezing of space.

Because gravity is weak, it is only possible for humans to detect the strongest of its ripples — such as when two black holes smash into each other.

Einstein thought the ripples would never be discovered by human technology because they were so small.

Why does the discovery matter?

The massive laser telescopes at LIGO have been trying to detect the waves. Photo: Getty

Proof of gravitational waves opens up a completely new field of astronomy, giving us a potentially sharper picture of the universe. For example, it could allow us to look even closer at the earliest instant after the Big Bang.

Everything we know about the cosmos stems from electromagnetic waves such as radio waves, visible light, infrared light, X-rays and gamma rays.
 But because such waves encounter interference as they travel across the universe, they give ‘blurry’ results that tells only part of the story.

Gravitational waves experience no such barriers, meaning they may give us cleaner, sharper images, offering a wealth of additional information far back in time and deep inside the most extreme objects in the sky.

The pattern of movement as black holes coalesce, the changes inside a supernova, the mechanisms of a gamma ray burst will all become visible to us.

This video explains what gravitational waves are:

– with AAP and ABC