Stuff that falls into a black hole is pulled beyond its event horizon, where it is ultimately compressed into an infinitely dense point known as a singularity.
The Irreversible Path Beyond the Event Horizon
When matter, whether it's a star, dust, or a stray atom, ventures too close to a black hole, it encounters an extreme gravitational pull. This force is so immense that beyond a certain boundary—the event horizon—nothing, not even light, can escape. This boundary marks the point of no return.
Spaghettification: The Stretching Effect
Before reaching the singularity, matter experiences an incredible phenomenon called spaghettification. This occurs because the black hole's gravity is much stronger closer to its center than it is slightly farther away. Imagine falling feet-first into a black hole: the gravitational pull on your feet would be vastly greater than on your head, stretching your body out like a noodle. This extreme differential gravitational force tears apart celestial bodies, stars, and ultimately, even individual atoms.
The Final Destination: The Singularity
Once inside the event horizon, matter's fate is sealed. It is subjected to ever-increasing gravitational forces. Matter, regardless of its original form, is torn apart into its smallest subatomic components. These particles are then squeezed into the singularity.
The Infinitely Dense Singularity
The singularity is the theoretical point at the heart of a black hole where all its mass is concentrated. It is believed to be a point of infinite density and zero volume. At this point, the laws of physics as we understand them, including those governing space and time, are thought to break down. Therefore, the "stuff" doesn't just cease to exist; rather, it contributes to the singularity's mass, becoming an inseparable part of this incredibly dense core.
Black Hole Growth and Event Horizon Expansion
As the singularity accumulates more and more matter, the black hole effectively grows. The more mass that falls in and is compressed into the singularity, the larger the black hole becomes. Consequently, the size of the black hole's event horizon increases proportionally. This means a larger black hole has a wider "point of no return" surrounding its singularity, encompassing more space and gravitational influence.
The Information Paradox and Hawking Radiation
While matter seems to vanish into the singularity, physicists grapple with the "information paradox" – what happens to the information contained within the matter that falls in? According to quantum mechanics, information cannot be truly destroyed. One leading theory, proposed by Stephen Hawking, suggests that black holes are not entirely "black." They slowly emit a faint thermal radiation known as Hawking radiation.
This radiation is not the original matter escaping; rather, it's energy that slowly causes the black hole to "evaporate" over an extremely long period, potentially billions or trillions of years. For practical purposes, however, for anything crossing the event horizon, there is no known way for it to escape or return to our observable universe.
