What is this mysterious black hole?
Let's first understand the life cycle of a star
stellar nebula
massive star
red supergiant
supernova
neutron star
black hole
A black hole is a region of space in which the gravitational field is so strong that nothing, not even light, can leave it
A black holes appear after the collapse of huge stars, when their core cannot resist gravity and collapses inward on itself
A black hole has a spherical shape and is invisible to an observer because it absorbs all light rays
Let's take a closer look at what a black hole consists of
Event horizon
A black hole has a gravitational field that is so strong that no radiation or matter can leave it. This gravitational field forms a boundary called the event horizon
When an object falls outside the event horizon of the black hole, it can no longer return and will be attracted to the center of the black hole until it reaches a singularity
Photon sphere
A spherical region of space in which photons (elementary particles of light) interact with matter in such a way that they cannot propagate freely either outward or inward in this region
This means that photons that are born inside the photon sphere will not be able to leave it, and photons that get inside the sphere will be stuck in it
Accretion disk
An accretion disk around a black hole is a rotating disk of gas and dust that forms when matter (such as the remnants of stars or gas) falls toward the black hole
When this matter approaches the black hole, it begins to rotate and heat up due to friction. This causes the disk to glow and emit energy, making it visible to astronomers
Singularity
The point in spacetime where curvature becomes infinite. In the context of black holes, the singularity is located in the center of the black hole and is considered to be the point at which the volume and density of matter become infinite
how do you detect a black hole if you can't see it?
There are some ways that can help detect a black hole:
Black holes can have accretion disks. The disk will emit X-rays and other kinds of radiation
When a beam of light passes through the gravitational field of a black hole, the gravitational forces curve its trajectory. This can lead to «gravitational lensing» effects
Rotating objects
Accretion disk radiation
Gravitational lensing
The gravity of a black hole can make different objects, such as a star, move around itself
What lurks on the other side of the black hole
Theoretically, there could be another region of space-time beyond the black hole
For example...
a secret alien base that learns human dances
an emergency exit from our reality where all the lost socks go
a warehouse stocked with popcorn for the universe where the gods watch our adventures
In fact, the scientific community has not yet been able to determine exactly what lies behind the black hole
Is it true that nothing can come out of black holes?
Stephen Hawking expressed the opinion that in quantum mechanics space-time is not empty. Here live virtual particles and antiparticles, which appear from vacuum for a very short time
If a particle-antiparticle pair occurs near the event horizon of a black hole, one of they can fall into the black hole and the other can fly off into outer space. Thus black holes, which normally absorb everything around them, begin to emit energy in the form of particles
This energy reduces the mass of the black hole until it reaches zero
reaches zero
