A black hole as an invisible spot in space where gravity is so intense that nothing can escape it. Even light is trapped by this celestial body. Black holes can form when a star has died and collapsed in on itself, becoming incredibly dense.
Black holes are hard to detect, but special telescopes in space are able to detect them by studying the movement of stars and gas around them. Scientists believe the Milky Way galaxy may be home to numerous black holes, and the size of black holes can range from the size of an atom to more than 1 million times the size of the sun.Learn More
A black hole is not, strictly, made of anything in the conventional sense. Black holes are so exotic that they defy commonsense ideas about matter. While an object such as Earth can be described in terms of its atoms and molecules, the unchecked gravity of a black hole shreds atoms until what remains is describable only as a quantum singularity.Full Answer >
Since Einstein's time, scientists have thought of gravity as a force governed by an incredibly small particle called a graviton, which is thought to be present throughout the universe. This particle is part of the theory of quantum gravity, which itself is a part of the effort to form the theory of everything.Full Answer >
Specific gravity, also known as relative density, is the ratio of the weight of a substance to the weight of an equal volume of water at a temperature of 4 degrees Celsius. The weight value in the equation can be substituted with the density of that substance.Full Answer >
Gravity is one of the fundamental forces of the universe, and it keeps us on Earth because it is relentlessly attractive. Every massive particle exhibits gravity by pulling closer to every other particle. The strength of this interaction is dependent on two quantities: the amount of mass and the distance between objects. It is possible to escape Earth's gravity if you have enough energy to speed up sufficiently.Full Answer >