At the center of our galaxy, a supermassive black hole churns. Learn about the types of black holes, how they form, and how scientists discovered these invisible, yet extraordinary objects in our universe. About National Geographic: National Geographic is the world's premium destination for science, exploration, and adventure. Through their world-class scientists, photographers, journalists, and filmmakers, Nat Geo gets you closer to the stories that matter and past the edge of what's possible.

What if every single black hole that formed in our universe sparked the big bang of a new universe? Cosmological natural selection proposes exactly this - but even better, it claims to be able to test the hypothesis. Physicists have been struggling for some time to figure out why our universe is so comfy. Why, for example, are the fundamental constants - like the mass of the electron or the strength of the forces - just right for the emergence of life? Tweak them too much and life, stars, galaxies, the universe as we know it wouldn’t exist. In recent episodes we explored one possible explanation for this - the anthropic principle and the idea of the multiverse. If there are countless universes with different fundamental constants, then it’s not surprising that a few exist with the right numbers for life - and certainly not surprising that we find ourselves in one of those good ones. But if you don’t like the anthropic principle - and many scientists don’t - then rest assured, there’s an alternative. You only need to accept two things: that our universe formed inside a black hole, and that universes can evolve.

This show was converted to 4K/UHD using an AI program. What do you think? For the best collection of 4k Space-Science content, go to... This SpaceRip classic explores one of the greatest mysteries in modern science: a series of brief but extremely bright flashes of ultra-high energy light coming from somewhere out in space. These gamma ray bursts were first spotted by spy satellites in the 1960s. It took three decades and a revolution in high-energy astronomy for scientists to figure out what they were: black holes at the moment of their birth. Far out in space, in the center of a seething cosmic maelstrom. Extreme heat. High velocities. Atoms tear, and space literally buckles. Photons fly out across the universe, energized to the limits found in nature. Billions of years later, they enter the detectors of spacecraft stationed above our atmosphere. Our ability to record them is part of a new age of high-energy astronomy, and a new age of insights into nature at its most extreme. What can we learn by witnessing the violent birth of a black hole? The outer limits of a black hole, call the event horizon, is subject to what Albert Einstein called frame dragging, in which space and time are pulled along on a path that leads into the black hole. As gas, dust, stars or planets fall into the hole, they form into a disk that spirals in with the flow of space time, reaching the speed of light just as it hits the event horizon. The spinning motion of this so-called "accretion disk" can channel some of the inflowing matter out into a pair of high-energy beams, or jets. How a jet can form was shown in a supercomputer simulation of a short gamma ray burst. It was based on a 40-millisecond long burst recorded by Swift on May 9, 2005. It took five minutes for the afterglow to fade, but that was enough for astronomers to capture crucial details. It had come from a giant galaxy 2.6 billion light years away, filled with old stars. Scientists suspected that this was a case of two dead stars falling into a catastrophic embrace. Orbiting each other, they moved ever closer, gradually gaining speed. At the end of the line, they began tearing each other apart, until they finally merged. NASA scientists simulated the final 35 thousandths of a second, when a black hole forms. Chaos reigns. But the new structure becomes steadily more organized, and a magnetic field takes on the character of a jet. Within less than a second after the black hole is born, it launches a jet of particles to a speed approaching light. A similar chain of events, in the death of a large star, is responsible for longer gamma ray bursts. Stars resist gravity by generating photons that push outward on their enormous mass. But the weight of a large star's core increases from the accumulation of heavy elements produced in nuclear fusion. In time, its outer layers cannot resist the inward pull... and the star collapses. The crash produces a shock wave that races through the star and obliterates it. In the largest of these dying stars, known as collapsars or hypernovae, a black hole forms in the collapse. Matter flowing in forms a disk. Charged particles create magnetic fields that twist off this disk, sending a portion out in high-speed jets. Simulations show that the jet is powerful enough to plow its way through the star. In so doing, it may help trigger the explosion. The birth of a black hole does not simply light up the universe. It is a crucial event in the spread of heavy elements that seed the birth of new solar systems and planets. But the black hole birth cries that we can now register with a fleet of high-energy telescopes are part of wider response to gravity's convulsive power.

At the center of a galaxy more than 55 million light-years away, there's a supermassive black hole with the mass of several billion suns. And now, for the first time ever, we can see it. Astrophysicist Sheperd Doeleman, head of the Event Horizon Telescope collaboration, speaks with TED's Chris Anderson about the iconic, first-ever image of a black hole -- and the epic, worldwide effort involved in capturing it. The TED Talks channel features the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and more.

How would it look to have four suns in the sky? Planets of the HD 98800 system, if they exist, would experience such a view. HD 98800 is a multiple star system about 150 light years from Earth - right in our section of the Milky Way Galaxy. For years it has been known that HD 98800 consists of two pairs of double stars, with one pair surrounded by a disk of dust. Recent data from the Earth-trailing Spitzer Space Telescope in infrared light indicate that the dust disk has gaps that appear consistent with being cleared by planets orbiting in the disk. If so, one planet appears to be orbiting at a distance similar to Mars of our own Solar System. Pictured below is an artist's drawing of how the HD 98800 system might appear to a nearby observer.