The relationship between black holes and galaxies is complex, with supermassive black holes likely playing a critical role in the formation and evolution of galaxies, possibly influencing their growth through jets of material they emit.

Almost all the information in the universe is in the form of black holes; they contain significantly more information than anything else.

When two black holes merge, they emit gravitational waves, and the final black hole's mass is less than the sum of the original black holes due to energy radiated away as gravitational waves.

The final mass of a merged black hole is less than the sum of the two original black holes due to the energy radiated away in the form of gravitational waves, which is not detectable as light but rather as ripples in spacetime.

Gravitational waves are created when massive objects like black holes move, causing ripples in the fabric of spacetime that can be detected on Earth.

Black holes curve space and time around them, creating a gravitational field that affects the movement of objects nearby. When two black holes orbit each other, they create waves in the shape of space that follow their movement, eventually merging into a larger black hole that emits gravitational waves as it settles down.

Inside the event horizon, the nature of space and time changes dramatically. As an object falls into a black hole, it experiences time differently, with their future leading them inevitably to the singularity, which is a point in time rather than space from their perspective.

Dark energy, which makes up 73% of the universe, could allow for a Type IV civilization that harnesses energy from the entire universe.

One of the most incredible things humans have accomplished is detecting gravitational waves through LIGO, which allows us to observe events from the early universe.