Scientists have again identified gravitational waves from black holes that smashed into each other, strengthening the general theory of relativity that was postulated by Albert Einstein a century ago.

They were located by the Laser Interferometer Gravitational-Wave Observatory, or LIGO. It is funded by the National Science Foundation and managed by Caltech and MIT.

"The gargantuan gravitational forces involved when two such incredibly dense objects ram into each other are so catastrophic that they wrench spacetime out of shape, curving it in powerful waves that travel clear across the cosmos," explains Scientific American.

You can listen to the interesting sound of the collisions here.

With this, new horizons of research open up in astronomy and astrophysics , which may even take us beyond his general theory of relativity, according to Dave Reitze, a professor of physics at the University of Florida, as well as executive director of LIGO.

"Gravitational waves are a different kind of information, and it is a kind of information we have never had before these two detections," Reitze said. "The gravitational wave is a way of understanding how massive objects like black holes and neutron stars move and accelerate. And when they collide and merge with each other, the gravitational wave signals we see gives us deep insights into the mechanisms, the dynamics of those collisions."

"This is a new kind of astronomy, this is a new frontier for high energy astrophysics," he said. "It will let us look at these events in ways that nobody else can look at them."

The second finding of waves was made on Dec. 26, and published Wednesday in the journal Physical Review Letters.

Earlier, LIGO scientists confirmed the waves in September 2015, announcing the detection on Feb. 11. Two LIGO detectors, one in Livingston, Louisiana, and another in Hanford, Washington, identified the waves.

The general theory of relativity shows that space curves around objects, and also affects their movements in space. Hence, gravitational waves like "ripples" are caused by large objects that move through space and create disturbances.

Signals were received from two black holes about 1.4 billion light years away. Being 14 and 8 times the size of the sun, they orbited each other and ultimately blended together, leading to an even larger massive black hole that was 21 times bigger than the sun. It sent ripples into space. In the original detection, they were about the same distance from earth as the latest one.

The detectors could "hear" the gravitational waves even as they ran in only half their full sensitivity, so "in the future, when we start running again, we are going to be seeing a lot of these binary black hole systems," Reitze added. "We are going to learn a lot about black holes, using LIGO. Even if nothing else comes into our detectors, we are going to own black hole astronomy."

In future, they can hope to see a number of other sources of waves, such as neutron stars colliding, or even, perhaps, a supernova going off somewhere in the galaxy.

"We are going to add to the future of this field, which we call multi-messenger astronomy, and I think that is very exciting," he explained.

The field is defined as the ability to collect data about space in ways much beyond traditional astronomy.

"The future of gravitational astronomy is very bright," he said."We are going to be discovering things we know or expect to see, but we are also going to be discovering things we did not expect to see.

"What would be my best hope is if we would start to see something in our data that might start to show that general relativity might not be right, at least in the regimes that we are looking at. So we would start to get a sense of what comes after general relativity. And that would be tremendously exciting. I am not going to bet against Einstein, but we could, and that would be fantastic."