There's no two without three

On January 4th, 2017, LIGO detected two black holes merging into one. One of the black holes was 32 times the mass of the Sun, while the other was 19 times the mass of the Sun. When they merged, they created a black hole 49 times the mass of the Sun. The coalescence instantly converted 2 solar masses of black hole mass into the energy that rattled spacetime enough to generate the gravitational waves we detected almost 3 billion years after it occurred. (Caltech/MIT/LIGO Lab)

Read also: LIGO Picks Up on the Third Ring

LIGO Scientific and Virgo Collaboration (2017). GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2 Physical Review Letters, 118 (22) DOI: 10.1103/PhysRevLett.118.221101

Another bit of gravity

by Marco De Angelis

After the first detection of gravitational waves from merged black holes, LIGO detected a new signal:

The two LIGO gravitational wave detectors in Hanford Washington and Livingston Louisiana have caught a second robust signal from two black holes in their final orbits and then their coalescence into a single black hole. This event, dubbed GW151226, was seen on December 26th at 03:38:53 (in Universal Coordinated Time, also known as Greenwich Mean Time), near the end of LIGO's first observing period ("O1"), and was immediately nicknamed "the Boxing Day event".

A paper (pdf) about this observation was published on Physical Review Letters:

The inferred component masses are consistent with values dynamically measured in x-ray binaries, but are obtained through the independent measurement process of gravitational-wave detection. Although it is challenging to constrain the spins of the initial black holes, we can conclude that at least one black hole had spin greater than 0.2. These recent detections in Advanced LIGO's first observing period have revealed a population of binary black holes that heralds the opening of the field of gravitational-wave astronomy.

About the first observation, GW150914, you can read Binary Black Hole Mergers in the first Advanced LIGO Observing Run and Dynamical formation of the GW150914 binary black hole (sci-hub) (or Black hole pairs spat out of mosh pits make gravitational waves).

via University of Birmingham

"We are hearing the universe"

When we describe a geometric space, we need to define a metric, or in other words a way to measure distances: in particular in general relativity we use the tensor metric, $g_{\mu \nu}$. Supposing the existence of gravitational waves, it is possible to calculate their effect on the radiation coming from some cosmic objects like a binary or a couple of merging black holes.

On September 14, 2015, within the first two days of Advanced LIGO's operation, the researchers detected a signal so strong that it could be seen by eye. The most intense portion of the signal lasted for about 0.2 s and was observed in both detectors, with a combined signal-to-noise ratio of 24. Fittingly, this first gravitational wave signal, dubbed GW150914, arrived less than two months before the 100-year anniversary of the publication of Einstein's general relativity theory.⁽¹⁾

A blink of an eye

Almost 14 billion years ago, the universe we inhabit burst into existence in an extraordinary event that initiated the Big Bang. In the first fleeting fraction of a second, the universe expanded exponentially, stretching far beyond the view of our best telescopes. All this, of course, was just theory.
Researchers from the BICEP2 collaboration today announced the first direct evidence for this cosmic inflation. Their data also represent the first images of gravitational waves, or ripples in space-time. These waves have been described as the "first tremors of the Big Bang." Finally, the data confirm a deep connection between quantum mechanics and general relativity.

(from the press release)

In physics, gravitational waves are ripples in the curvature of spacetime that propagate as a wave, travelling outward from the source. Predicted in 1916 by Albert Einstein to exist on the basis of his theory of general relativity, gravitational waves theoretically transport energy as gravitational radiation. Sources of detectable gravitational waves could possibly include binary star systems composed of white dwarfs, neutron stars, or black holes. The existence of gravitational waves is a possible consequence of the Lorentz invariance of general relativity since it brings the concept of a limiting speed of propagation of the physical interactions with it. Gravitational waves cannot exist in the Newtonian theory of gravitation, in which physical interactions propagate at infinite speed.

(from Wikipedia) Cosmic inflation was introduced by Alan Guth and Andrei Linde in 1981:

One of the intriguing consequences of inflation is that quantum fluctuations in the early universe can be stretched to astronomical proportions, providing the seeds for the large scale structure of the universe. The predicted spectrum of these fluctuations was calculated by Guth and others in 1982. These fluctuations can be seen today as ripples in the cosmic background radiation, but the amplitude of these faint ripples is only about one part in 100,000. Nonetheless, these ripples were detected by the COBE satellite in 1992, and they have now been measured to much higher precision by the WMAP satellite and other experiments. The properties of the radiation are found to be in excellent agreement with the predictions of the simplest models of inflation.

(from MIT)
So our universe is born after a quantum blink of an eye, or like a solution of the equation of everything.
In the following a storify with a collection of link about one of the most important discovery of the... universe!