Recently, scientists observed the merger of giant ‘blackholes’ billions of light-years away from the Earth. What is the significance of this observation?

The merger of giant black holes, billions of light-years away, is significant because it resulted in the detection of gravitational waves.

When two black holes collide and merge, they release immense energy, some of which is converted into gravitational waves. These waves are ripples in the fabric of spacetime.

The observed merger involved black holes with a combined mass more than 80 times that of the sun, releasing energy equivalent to five solar masses in the form of gravitational waves.

This event was detected by gravitational wave detectors on Earth and is the most distant collision detected so far, approximately nine billion light-years away.

The detection of gravitational waves confirms predictions made by Einstein's theory of general relativity.

Therefore, the correct answer is that 'Gravitational waves' were detected.

Sources:

• Cosmos Magazine