Answer:
fragile
Step-by-step explanation:
from A Black Hole is NOT a Hole
Gravity is the source of a black hole’s super pull.
You deal with gravity every day. You count on it to bring you back to the ground when you jump up. You depend on it when you try to catch a pop fly, knowing the ball will fall down. You expect it to be there, even if you don’t think about it much.
People must have always noticed that objects fall, but they didn’t know what made this happen. They certainly didn’t guess that falling objects had anything to do with the stars, Moon, planets, and Sun—but then one man came along with some new ideas.
That man was Isaac Newton. In 1687 he proposed that objects fall to the ground because Earth pulls on them. But his idea reached beyond Earth. He suggested that all things pull on each other, even when they are not touching. He considered this pull a force of nature and referred to it as gravitas—whatwe now call gravity.
According to Newton, the force of gravity is a two-way tug between any two objects. It works with anything—any matter at all. The matter can be a tiny bit of a thing, as small as a speck of stardust. It can be a huge collection of material, as gigantic as a galaxy. It can be as rigid as rock or as flimsy as flame. No matter what it is, if it’s made of matter, then it possesses the power to pull on anything else.
Newton also noted that in any situation, the strength of the pull depends on how much matter, or mass, is involved. When there’s a lot of matter, there’s a strong pull. Less matter means a weaker pull. For example, imagine a fluffy snowball and a harder-packed snowball of the same size. The fluffier ball is made of less stuff. Its pull is wimpier than the pull of the densely packed ball.
You can feel this difference when you hold the two snowballs in your hands. Each one presses down on your hand because of the gravitational attraction it shares with Earth. The hard-packed snowball has a stronger attraction to Earth because it is made of more material. It presses more forcefully than the fluffy one. It feels heavier.
Gravity works everywhere in the universe (as far as anyone can tell). It’s gravity that holds the solar system together. Even faraway Pluto and Neptune, as well as the outer comets, are gravitationally connected to the Sun. Instead of flying off into other parts of space, they stay in our solar neighborhood. The Sun’s gravitational pull extends so far out because the Sun has a lot of matter packed into it—about five hundred times the mass of everything else in the solar system combined!
Even so, our Sun and solar system are just a tiny part of the universe. Most things are too far away to be swept in by the Sun’s gravity. Thanks again to Newton, we know that the closer things are, the harder they pull on each other, and the farther apart they are, the weaker they pull.
This is true for all matter in the universe, including black holes. It’s just that with black holes, the close-up effect is extreme.
How densely packed is the material that forms a black hole? Imagine a black hole the size of a snowball. Now compare it to a “snowball” made of different materials.
A snowball-sized
Ball of fluffy snow
Ball of hard-packed snow
Rock (granite)
Ball of plasma from the Sun’s center
Black hole* Has a mass of
37 grams
87 grams
287 grams
29,000 grams
50 octillion grams This weighs about the same as
A slice of bread
A small candy bar
A rock, of course!
An 8- or 9-year-old human
*In a black hole the size of a snowball, most of the “snowball” would be empty space (the extreme gravity zone) surrounding a densely packed center. The center would contain all the mass, yet take up less room than a single snowflake.
Remember that super-pulling space around a black hole—the one with the strongest pull in the universe? That super pull is the close-up gravitational power of a black hole. Here in this zone, the gravity is so intense that nothing can move fast enough to fly, launch, jump, or zoom away.
Around this extreme zone is a boundary called the event horizon. This boundary acts like a point of no return. Once past it, there’s no going back. Only black holes have such extreme gravity zones, and only black holes have event horizons. This is what makes a black hole different from everything else.
But a black hole is more than just a gravity zone—more than just empty space inside an event horizon. A black hole also includes the source of its tremendous gravitation: a massive amount of densely packed matter sitting at its center. The matter is so densely packed that it forms a single point, called a singularity.