Stories tagged black holes

Jul
11
2008

Spiral galaxy M81: The black hole in the center of this galaxy is 70 million times as massive as the Sun, but it behaves exactly the same as much, much smaller black holes.
Spiral galaxy M81: The black hole in the center of this galaxy is 70 million times as massive as the Sun, but it behaves exactly the same as much, much smaller black holes.Courtesy X-ray: NASA/CXC/Wisconsin/D.Pooley & CfA/A.Zezas; Optical: NASA/ESA/CfA/A.Zezas; UV: NASA/JPL-Caltech/CfA/J.Huchra et al.; IR: NASA/JPL-Caltech/CfA

This may fall under the heading of small comfort, but a new study has shown that all black holes, big or small, suck in matter in the same way. Using NASA’s Chandra X-ray observatory, astronomers studied the different types of light (X-ray, radio and visible) emanating from the region around a massive black hole in the center of galaxy M81. They found that this light was the same as light coming from smaller black holes, even though this one is some 10 million times bigger, and is sucking in matter from a different source. This confirms a part of Einstein’s theory of relativity, which predicted that black holes would be fairly simple objects, not subject to a lot of variation. Which doesn’t really help much if you find yourself getting sucked in, but at least you know it’s nothing personal.

You can learn more about Chandra and X-ray astronomy in our Be an Astronomer! web exhibit. And you can ask questions of Megan Donahue, a scientist who work with the Chandra observatory.

Jul
01
2008

But what a way to go!: Look! I can see my house! Right on the center left, being sucked into an ultra dense, inescapable mass!
But what a way to go!: Look! I can see my house! Right on the center left, being sucked into an ultra dense, inescapable mass!Courtesy NASA
So, what? You wanted to live forever?

Oh, you did? Er…even at the expense of scientific enterprise? Whatever. Deal with it, crybaby, because me and my little Strangelet are going to wring this planet dry.

Do you remember the Large Hadron Collider? No? We posted about it this spring on Science Buzz. It’s a recently completed supercollider in France and Switzerland—the largest supercollider in the world, with a 17-mile circumference. Protons will be blasted through the device so fast that they’ll make the entire circuit 11,000 times per second (which is about the speed of light, I believe). When two streams of protons meet, some of them will collide, and smash apart. At that point two huge detectors will attempt to gather data on just what comes out of the destroyed protons. The hope is that when the machine is switched on in August, we’ll make some fantastic discoveries about the most basic (and yet mysterious) elements of matter.

Oh, and the world might be instantly destroyed. I didn’t mention that last time? Huh. I suppose it just slipped my mind because, you know, who wants to live forever, right?

Some people (read: crybabies) are very concerned that the colliding particles could form a micro-black hole, which could either evaporate instantly, or gobble up the earth. Whoops! There’s some thought that the collider might also produce a spicy little devil we call the “strangelet.”

Stranglets are, it should be said, hypothetical—they’ve never actually been observed. A strangelet is basically a tiny piece of “strange matter,” stuff made up of the same components of regular vanilla matter, but in a unique configuration (equal amounts of up, down, and strange quarks, for those of you in to…quarks, I guess). The fear is that, where a strangelet to come into contact with regular matter on Earth, it could convert that matter into another strangelet, which would convert other matter into strangelets, until the whole of Earth would be turned into a big ball of hot strange matter. Which would just be the pits.

A particular group of people was so worried about the repercussions of turning on the LHC that they actually filed an injunction against its operators. The lawsuit was dismissed, on account of the defenders of humanity just “needing to chill out.”

The plaintiffs claimed that the odds of the LHC creating a global catastrophe are about one in fifty-million—about the same as winning the lottery, but that happens from time to time. Not to me, though.

The scientists behind the LHC, however, argue that the odds are much lower than that even, if not zero. Collisions like those planned for the LHC occur naturally every second, as cosmic rays smack into the earth, and so far everything is all right. Furthermore, should something like a micro-black hole be formed, mega-eggheads like Stephen Hawking predict that it would instantly turn to nothing.

And that’s kind of the thing—some of the world’s biggest smarty-pants are working on this project, and they aren’t concerned. That has to mean something, right? Then again, according to The Incredible Hulk, many scientists aren’t all that concerned about their own certain, imminent death, so long as they get to do some crazy experiments. And I trust comic books implicitly, so who knows.

Nov
02
2007

Galactic glue: Are supermassive black holes holding our galaxies together? That's the conclusion many astronomers are coming to as they study these huge, massive sites at the core of many galaxies. (Photo courtesy of NASA)
Galactic glue: Are supermassive black holes holding our galaxies together? That's the conclusion many astronomers are coming to as they study these huge, massive sites at the core of many galaxies. (Photo courtesy of NASA)
The black hole: our metaphor du joir to describe something that completely sucks up another thing.

But new research is re-examining black holes and the impact they play in space. Not only are they sucking up old space materials, but they may be spitting out new galactic bodies and holding complete galaxies together.

UCLA astronomer Andrea Ghez is at the hub of this new research. Using some of the most technically advanced telescopic equipment available, for four years she’s been watching and reporting on new black hole phenomena. And she may have uncovered a new, more powerful type of black hole, the “supermassive” black hole.

She and others who are studying the same things now postulate that most of the universe’s galaxies have “supermassive” black holes at their center. These mega-black holes have gravitational fields that are hundreds of thousands of times stronger than the conventional black hole.

While research for a long time has chronicled how regular black holes can eat up stars, planets and even light, the new supermassive black holes might also be celestial body creators. Just like what often happens to us after eating a big meal, these super-sized black holes belch out jets of energized particles and radiation over a distance of millions of light years, creating new galaxies and celestial bodies.

If your sitting there starting to feel a mysterious uncomfortable tug on you, don’t worry. Here in the Milky Way it’s believed we have a very small, dormant supermassive black hole holding our galaxy together. It’s about 27,000 light years away from us and is relatively small, having the mass of about 4 millions suns. And there’s no evidence that it is spewing out any jets of radiation and energy particles.

More on supermassive black holes

Oct
13
2005

Scientists have finally solved the mystery of gamma ray bursts, the most violent explosions in the universe. Lasting a fraction of a second, they release 100,000,000,000,000 (100 trillion) times more energy than the Sun. But since they were first detected in 1970, scientists have wondered what exactly gamma ray bursts are.

Now, thanks to three satellites and four ground-based telescopes, they have figures out that the explosions occur when two neutron stars collide, or when a neutron star is swallowed by a black hole.

A neutron star is an old star that has burned off most of its fuel and collapsed under its own weight. Though they are only about 10 miles across, they weigh 1 1/2 times as much as the Sun. Gravity squeezes the atoms of together until the protons and electrons merge, forming neutrons.

Collisions between neutron stars can also create black holes. This study may give scientists their first chance to learn how black holes are formed.