Verum looked up from her crystal ball and said, “Orak, I need your help to understand today’s news. It’s quite sciency-wiency. It’s about supermassive black holes.”
“Yay! That’s one of the most mysterious topics in science,” said an excited Orak.
Felix said, “I still don’t understand what exactly are black holes. Are they holes that are black in color?”
Orak stepped in with an explanation, “A black hole is a region of space with strong gravity. Gravity is a force that attracts objects toward each other. It is present everywhere in the universe. Due to its powerful gravity, black holes attract and consume everything close to it.”
“But we cannot observe black holes directly. They are invisible to us,” added Verum, “However, scientists did find a way! They observed black holes through their effect on nearby planets or stars. When an object is about to enter a black hole, it gives off energy. Scientists can detect the energy and study the black hole. The other way to study black holes is through gravitational waves.”
“To understand gravitational waves, we need to understand neutron stars,” said Orak, “Stars are made up of hydrogen gas. Hydrogen is its fuel. When a star runs out of hydrogen gas, it cannot produce energy anymore. So, the star’s gravity starts crushing it to become smaller and smaller. And it explodes into a supernova!”
He added, “If the dying star was six to eight times the mass of the Sun, its outer layers could blow off in a spectacular display. But its inner core remains – which is super dense. It’s called a neutron star. When a black hole collides with a neutron star, it creates ripples in spacetime. These ripples are called gravitational waves.”
“Thank you, Orak,” said Verum, “These waves were first detected in 2015. Since then huge observatories like the Laser Interferometer Gravitational-wave Observatories (LIGO) in the United States, and the Virgo facility near Pisa, Italy, have been detecting these waves. But they have certain limitations. They can detect gravitational waves only from relatively modest-sized black holes.”
“That brings us to supermassive black holes,” said Orak, “A supermassive black hole is extremely large. It has the mass of millions of stars! But very little is known about these monstrous entities.”
“This is set to change with the development of new telescopes and techniques,” said Verum, “In the 2030s, the United States National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) will launch Laser Interferometer Space Antenna (LISA). LISA will be powerful enough to gather data about supermassive black holes.”