英语听力：自然百科 探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit02（在线收听）

探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit02

But we are just one in 125 billion galaxies of different shapes and sizes spinning through space. Yet scientists haven't been able to explain how a single one of these galaxies was created.

Galaxy formation is a very complicated process, we think, it involves gravity and it involves large balls of gas colliding, it involves the dynamics of stars and it involves the chemistry of the gas coming together.

All we know is that when the universe was young, there were no stars or planets, just great swirling clouds of hydrogen gas. The mystery is how each of these clouds turned into the complex galaxies of stars we see today.

We just don't know how they do it, how galaxies formed out of the, the ionized hot gas that('s) filled the universe is still physics that we do not really understand yet.

Exactly how galaxies were created has troubled the world's leading astronomers and physicists for decades. But in March 2000, scientists found evidence for an extraordinary answer.

The Nuker team is a group of world respected astronomers, but they are not galaxy experts. They are experts in the most violent and destructive forces known to science---supermassive black holes. Until recently, supermassive black holes were mere theory. These are giant black holes of apocalyptic proportion.

Supermassive black holes are a million to a billion times the mass of, of a, of a typical black hole.

They could fill a whole solar system.

ionization: Process by which electrically neutral atoms or molecules are converted to electrically charged atoms or molecules (ions) by the removal or addition of negatively charged electrons.

The Nuker Team was organized in 1985 to use Hubble Space Telescope high-resolution imaging and spectroscopy to investigate the central structure and dynamics of normal galaxies