August 2001
Isacc Newton determined in the late 1600’s that the force of gravity was due to matter or more specifically mass. The force of gravity is created by mass and gravity always attracts other mass. Newton’s theories first appeared in his famous book, "The Principia." In the 1700’s scientists speculated on the existence of massive objects with tremendous gravitational forces which today we call black holes. However it was not until Einstein published his theory of general relativity in 1915 that the black hole theory really received wide attention.
Relativity showed that gravity is related to the curvature of space and that a black hole is a place where the curvature becomes so extreme that a "hole" forms. Imagine a waterbed with a flat surface. Now place a bowling ball on it, the surface is distorted or bent. With a lot of mass, say a lead bowling ball, a "hole" forms on the surface of the bed. Similarly, a mass distorts or bends space. To form a black hole, a lot of matter is needed and must be concentrated in a small amount of space.
With sufficient mass, gravitational attraction within the matter itself overcomes all other forces and matter begins to collapse. The matter continues to collapse to a point that is known as a singularity. This point has infinite density and is infinitely small. The effect of this point on space-time is to distort it so that nothing can escape from the immediate region, not even light. Since no light can escape we say the region is black hence the name black hole. Near singularities the known laws of physics break down. For this reason considerable time and effort is being spent studying this strange phenomena.
In 1916, German astrophysicist Karl Schwarzschild derived an equation for the radius of a black hole. This Schwarzschild radius, also called the event horizon, is proportional to the mass of the black hole, M, and may be written as Rs = (1.48 x 10-27) times M. This radius is the point or distance from the singularity at which light can still escape from the region. At a distance less than the event horizon radius, everything disappears. Although the matter at the center is really a singularity, we say it is a black hole the size of the event horizon distance.
When matter falls into or comes closer than the event horizon of a black hole, it becomes isolated from the rest of space-time. It can never leave that region. For all practical purposes the matter has disappeared from the universe. Once inside the black hole’s event horizon, matter will be torn apart into its smallest subatomic components and eventually be squeezed into the singularity. As the singularity accumulates more and more matter, the size of the black hole’s event horizon increases proportionally.
While everyone thought matter in a black hole was gone forever, Stephen Hawking in 1974 predicted that black holes could radiate energy away (Hawking radiation). Thus a black hole may give up some of what it had absorbed, but it does so very, very slowly. Theoretically then we say a black hole may evaporate over time by the emission of energy, but the time it would take for even a small black hole to evaporate is beyond our comprehension, on the order of a one with 67 zeros of years. Considerable work is needed to understand these strange phenomena, but for now that is where our understanding of physics has taken us.
FAQs
Once inside the black hole's event horizon, matter will be torn apart into its smallest subatomic components and eventually be squeezed into the singularity. As the singularity accumulates more and more matter, the size of the black hole's event horizon increases proportionally.
Where does matter go when it enters a black hole? ›
Once inside the black hole the matter will be torn apart into its smallest subatomic components which will be stretched and squeezed until they to become part of the singularity and increase the radius of the black hole accordingly.
How do black holes absorb matter? ›
Black holes grow in mass by capturing nearby material. Anything that enters the event horizon cannot escape the black hole's gravity. So objects that do not keep a safe distance get swallowed. Despite their reputation, black holes will not actually suck in objects from large distances.
What happens when dark matter falls into a black hole? ›
As the mass of the black hole enhances, the dark matter sees its distribution contract, become more compact and denser. The black hole accumulates a colossal black mass that is equivalent to dark energy. The latter means a gigantic density of matter- dark energy inside the horizon.
What happens when you get sucked into a black hole? ›
If you leapt heroically into a stellar-mass black hole, your body would be subjected to a process called 'spaghettification' (no, really, it is). The black hole's gravity force would compress you from top to toe, while stretching you at the same time… thus, spaghetti.
Does time exist in a black hole? ›
From the viewpoint of an observer outside the black hole, time stops. For example, an object falling into the hole would appear frozen in time at the edge of the hole. Inside a black hole is where the real mystery lies. According to Einstein's theory, time and space, in a way, trade places inside the hole.
Where does energy go in black holes? ›
While no energy can escape from beyond the event horizon around the black hole, energy is released from the material as it falls in. Accretion onto a black hole is the most efficient process for emitting energy from matter in the Universe, releasing up to 40% of the rest mass energy of the material falling in.
What would happen if a human fell in a black hole? ›
A jump into a black hole is a one-way trip. Black holes are regions of space where gravity is so strong that nothing can escape them, not even light. Even before you reach the event horizon – the point of no return – you would be “spaghettified” by the black hole's tidal forces.
Will everything eventually fall into a black hole? ›
Unlikely. Recent developments that show our universe is expanding at an ever-increasing rate.
Can a black hole swallow dark matter? ›
The team's results, published Jan. 30 in The Astrophysical Journal Letters, help to confirm a long-held theory in cosmology that black holes can swallow dark matter that comes close enough to them.
Your body stretches out, not uncomfortably at first, but over time, the stretching will become more severe. Astronomers call this spaghettification because the intense gravitational field pulls you into a long, thin piece of spaghetti. When you start feeling pain depends on the size of the black hole.
Would Earth survive a black hole? ›
If the Sun were replaced by an equally massive black hole, all the planets would remain in their present orbits, circling the black hole at a safe distance. Life would be impossible without the light and heat from the Sun, but at least Earth would survive.
Can a human survive entering a black hole? ›
A stellar-mass black hole would quickly tear you apart. But a person encountering a supermassive black hole could survive for hours.
What happens if strange matter touches a black hole? ›
If strange matter, which is incredibly dense and stable, were to encounter a black hole, theoretical predictions suggest it might be absorbed. The interaction's specifics, such as whether strange matter could alter the black hole's properties, remain a topic of speculation among physicists.
What is at the bottom of a black hole? ›
Black holes have two parts. There is the event horizon, which you can think of as the surface, though it's simply the point where the gravity gets too strong for anything to escape. And then, at the center, is the singularity. That's the word we use to describe a point that is infinitely small and infinitely dense.
Do black holes recycle matter? ›
So black holes have numerous essential and necessary roles in the Universe. Their first role is to recycle spatial debris and reproduce them as valid universal building material. As the black hole sucks and decomposes debris, it then releases the material and excess energy into space.
Is information lost in a black hole? ›
In physics, information can't just disappear, but if something falls into a black hole and the Hawking radiation only contains some of the information about it, then when the black hole evaporates some information would be lost forever.
