Scientists still have a lot to learn and discover about the mysterious celestial objects known as black holes. These cosmic bodies are known for absorbing everything as they form. Still, an old theory says that black holes have another purpose for advanced alien civilizations.
A hypothesis proposed by British physicist Roger Penrose back in 1969 suggests that a black hole could produce energy by bringing an object towards its ergosphere, which is placed at the outer layer of the black hole’s event horizon. It was speculated that aliens could use these spaces objects to generate energy. By 1971, physicist Yakov Zel’dovich suggested that Penrose’s theory could be tested in a more practical experiment.
Now, researchers from the University of Glasgow’s School of Physics and Astronomy have made some progress in testing both Penrose and Zel’dovich’s theories. Rather than twisting light waves as the latter hypothesis suggested, the scientists twisted sound waves because of its low-frequency source and also because it is easier to test.
Shifting the Frequency
Their aim was to listen for a certain change in frequency and amplitude of the sound waves as it moves through the disc via the doppler effect. The experts found that there was a 30 percent increased amplitude compared to the original.
Lead author Marion Cromb said: “What’s happening is that the frequency of the sound waves is Doppler-shifted to zero as the spin speed increases. When the sound starts back up again, it’s because the waves have been shifted from a positive frequency to a negative frequency. Those negative-frequency waves are capable of taking some of the energy from the spinning foam disc, becoming louder in the process – just as Zel’dovich proposed in 1971.”
Previously, NASA’s Chandra X-ray Observatory was able to capture a flare-up emitted by the black hole and its companion star known as MAXI J1820+070, located 10,000 light-years away from Earth. The black hole boasts a mass of eight times than that of the Sun, and researchers have labeled it as a stellar-mass black hole, which is the outcome of a dying star that collapsed on itself.