Black holes are made of matter packed so tightly that gravity overwhelms all other forces.
When you pick up a bowling ball, it’s heavy because the matter is densely packed. If you packed more and more mass into the same tiny space, eventually it would create gravity so strong that it would exert a significant pull on passing rays of light.
Black holes are created when massive stars collapse at the end of their lives (and perhaps under other circumstances that we don’t know about yet). One of the first steps toward the discovery of black holes was made by University of Chicago professor Subrahmanyan Chandrasekhar, when he realized that massive stars would have to collapse after they ran out of fuel for the fusion reactions which keep them hot and bright.
The universe is full of black holes. In the past decade, scientists have detected the signals of their collisions and taken images of the light from the gas swirling around them—and this has helped us learn many things about the universe. For example, black holes have helped us test Einstein’s theory of general relativity, which describes how mass, space, and time are related to one another. Scientists think they can tell us much more about these and other essential rules of the universe. Continue reading from the UChicago News
From the wealth of Hubble data, astronomers now understand that black holes can have profound influences on the galaxy as a whole. For example, the jets from supermassive black holes can propel massive amounts of gas and dust into intergalactic space, thus ridding the galaxy of much-needed fuel for ongoing star formation. Or in the case of a 2015 result using Hubble observations of large elliptical galaxies, jets from supermassive black holes may regulate star formation in such a way that it keeps going, albeit at a slower rate.
Perhaps the most surprising result from Hubble’s observations is that supermassive black holes must reside in the majority, or even in all, galaxies. Once the objects of extreme speculation, supermassive black holes are now considered integral components of galaxies and crucial to the study of how galaxies evolve over time. Continue reading from NASA Hubblesite
Our solar system formed about 4.5 billion years ago from a dense cloud of interstellar gas and dust. The cloud collapsed, possibly due to the shockwave of a nearby exploding star, called a supernova. When this dust cloud collapsed, it formed a solar nebula—a spinning, swirling disk of material.
At the center, gravity pulled more and more material in. Eventually the pressure in the core was so great that hydrogen atoms began to combine and form helium, releasing a tremendous amount of energy. With that, our Sun was born, and it eventually amassed more than 99 percent of the available matter. Continue reading from NASA
