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Reality-Bending Black Holes




Black holes curve the fabric of spacetime so extremely that it rends. The superdense objects devour anything--even light--that strays too close, a trip from which there is no escape. Perhaps their most singular power, however, is their hold on our imagination. Learning more about these implacable gluttons offers the same shivery frisson as watching a stalking horror-movie creature while knowing we are safe in our cushioned seats.

As the authors in this special issue explain, black holes offer much more to science than the can't-look-can't-look-away spectacle of destruction. The forces they unleash shape the regions around them, providing clues to the evolution of stars and galaxies. For instance, the dark sinkholes reveal a surprising bright side. In their quest to solve an enduring mystery, astronomers have learned that black holes are responsible for some of the most dazzling fireworks in the universe. When a massive star collapses to birth a black hole, it releases a titanic pulse of radiation in a gamma-ray burst that can be seen from billions of light-years away, as Neil Gehrels, Luigi Piro and Peter J. T. Leonard discuss in their article, "The Brightest Explosions in the Universe." Greedily feeding supermassive black holes also exist in regions called starbursts, where stars are forming at a phenomenal rate. How? Turn to "The Galactic Odd Couple," by Kimberly Weaver.

Studying black holes yields insights into other mind-bending areas of physics. In the coming years the highest-energy particle accelerators on earth might be able to produce distant cousins of the astrophysical behemoths: microscopic black holes. They would explode immediately after they formed, giving clues about how spacetime is woven together and whether it has unseen higher dimensions, explain Bernard J. Carr and Steven B. Giddings in "Quantum Black Holes." Still other features in the issue explore what black holes can tell us about time travel, the nature of gravity, the ultimate amount of information the universe can hold and whether our seemingly 3-D reality is actually an illusion. So draw up that comfortable chair and get ready to learn more about one of the most awesome beasts in the universe. --The Editors

THE FORCES WITHIN

The Reluctant Father of Black Holes by Jeremy Bernstein
Albert Einstein's equations of gravity are the foundation of the modern view of black holes; ironically, he used the equations in trying to prove that these objects cannot exist

An Echo of Black Holes by Theodore A. Jacobson and Renaud Parentani
Sound waves in a fluid behave uncannily like light waves in space. Black holes even have acoustic counterparts. Could spacetime literally be a kind of fluid, like the ether of pre-Einsteinian physics?

Quantum Black Holes by Bernard J. Carr and Steven B. Giddings
Physicists could soon be creating black holes in the laboratory

How to Build a Time Machine by Paul Davies
It wouldn't be easy, but it might be possible

VIOLENT BIRTHS

The Brightest Explosions in the Universe by Neil Gehrels, Luigi Piro and Peter J. T. Leonard
Every time a gamma-ray burst goes off, a black hole is born

The Galactic Odd Couple by Kimberly Weaver
Why do giant black holes and stellar baby booms, two phenomena with little in common, so often go together?

Colossal Galactic Explosions by Sylvain Veilleux, Gerald Cecil and Joss Bland-Hawthorn
Enormous outpourings of gas from the centers of nearby galaxies may ultimately help explain both star formation and the intergalactic medium

The Midlife Crisis of the Cosmos by Amy J. Barger
Although it is not as active as it used to be, the universe is still forming stars and building black holes at an impressive pace

BENDING PHYSICS

Information in the Holographic Universe by Jacob D. Bekenstein
Theoretical results about black holes suggest that the universe could be like a gigantic hologram.

The Illusion of Gravity by Juan Maldacena
The force of gravity and one of the dimensions of space might be generated out of the peculiar interactions of particles and fields existing in a lower-dimensional realm

Black Hole Computers by Seth Lloyd and Y. Jack Ng
In keeping with the spirit of the age, researchers can think of the laws of physics as computer programs and the universe as a computer