What Exactly Is a Black Hole?
A black hole is a region of space where gravity is so strong that nothing — not even light — can escape once it passes a boundary called the event horizon.
Black holes are not cosmic vacuum cleaners. They only affect objects that come very close to them, just like any other massive object.
How Black Holes Form
Most black holes form from the deaths of very massive stars.
The process:
A massive star runs out of fuel
Fusion stops in the core
Gravity causes the core to collapse
If the core is massive enough, it collapses indefinitely
The result is a black hole with immense density.
Types of Black Holes
There are three main types:
Stellar black holes
Form from collapsing stars
A few to tens of solar masses
Supermassive black holes
Found at galaxy centres
Millions to billions of solar masses
Intermediate black holes
Still being actively studied
The Milky Way contains a supermassive black hole called Sagittarius A*.
Event Horizon & Singularity
Event Horizon: The point of no return
Singularity: The central region where current physics breaks down
We do not yet understand what truly happens at the singularity.
Key Takeaways
Black holes are real, measurable objects
They form from extreme gravitational collapse
They don’t “suck in” everything
Their behaviour follows known physics (mostly)