Black Holes: Event Horizon and Singularity

Study Notes

The point of no return around a black hole where the gravitational pull is so strong that anything, including light, cannot escape
Marks the boundary beyond which anything that enters cannot leave the black hole
Not a physical surface but a mathematical boundary
Once crossed, the curvature of spacetime is so extreme that escape is impossible

A point of infinite density and zero volume at the center of a black hole
The laws of physics as we know them break down at this point
Singularity is thought to be a one-dimensional point, rather than a region
The extreme gravitational pull of the singularity warps spacetime, creating the event horizon

Formed when a massive star collapses in on itself and its gravity becomes so strong that it warps spacetime
Can also be formed through the merger of two neutron stars or black holes
The collapse of a star with a mass at least three times that of the sun can create a black hole
Supermassive black holes found at the centers of galaxies are thought to have formed through the merger of smaller black holes.

The event horizon is the critical boundary around a black hole marking the point of no return.
Once crossed, all matter and light are trapped, unable to escape due to the intense gravitational pull.
It is a theoretical construct, not a physical surface, representing a mathematical limit.
At the event horizon, the curvature of spacetime becomes extreme, making escape physically impossible.

The singularity exists at the core of a black hole, representing a point of infinite density and negligible volume.
Conventional laws of physics cease to apply at this point, leading to a breakdown of our understanding of the universe.
It is considered a one-dimensional point rather than a defined region in space.
The singularity's immense gravitational influence distorts spacetime, thereby creating the event horizon.

Black holes exhibit unique characteristics due to their extraordinarily strong gravitational force.
The gravitational strength is so pronounced that even light cannot escape once it enters the vicinity.
The gravitational pull is proportional to the mass of the black hole; larger black holes exert a stronger gravitational force.
It is the mass and density of a black hole that dictates its gravitational influence over surrounding objects.

Black holes originate from the collapse of massive stars that implode under their own gravity.
They can also form through the merger of two neutron stars or existing black holes.
A star must have a mass exceeding three times that of the sun to be capable of forming a black hole upon its collapse.
Supermassive black holes, typically located at galactic centers, are believed to have developed from the accumulation and merger of smaller black holes over time.