Cidersomerset
8th January 2012, 16:47
I was watching a news article on the BBC this morning and they had a report on Dark Matter saying that scientists now thought it kept everthing in place stoping Stars and planets flying apart...
NASA/ Hubble Deep Field Team
http://www.centauri-dreams.org/wp-content/uploads/2007/05/dark_matter_ring.jpg
When you look up at night, you see myriads of stars spread across the sky. When astronomers look into the deepest reaches of the universe with powerful telescopes, they see myriads of galaxies, organized into large clusters and other structures. This might lead you to believe that the universe is composed mainly of galaxies, stars, gas and dust -- things that you can see. However, most astronomers believe that visible matter makes up only a small fraction of the mass of the universe. The majority of the universe is made of stuff we can't see -- so-called dark matter. Exactly what is dark matter? How can we detect it? What is its importance in the universe as a whole?
In this article, we'll examine these questions. We will look at the evidence for dark matter, how it can be detected and studied, the nature of dark matter, and how it helps define the structure and fate of the universe.
What is Dark Matter?
Simply put, dark matter cannot be seen by astronomers with telescopes. It doesn't emit or reflect enough light to detect, so it's not bright, like a star. Atoms, molecules and subatomic particles are dark matter. You and I are dark matter. Everything on Earth is dark matter. Planets, brown dwarf stars and black holes are dark matter. Basically, dark matter cannot be seen -- scientists can only estimate where it is based on gravitational effects on what they can see.
We can't see dark matter, but we can detect it by its effects on normal matter through gravity (rotation, gravitational-lensing) and by the X-rays emitted by hot, dark matter. So, what actually is dark matter? What is it made of? Let's take a look.
0ZoC2-_uVqo
http://science.howstuffworks.com/dictionary/astronomy-terms/dark-matter.htm
http://www.newscientist.com/article/mg21328465.800-mundane-dark-matter-may-lurk-in-starry-clusters.html
NASA/ Hubble Deep Field Team
http://www.centauri-dreams.org/wp-content/uploads/2007/05/dark_matter_ring.jpg
When you look up at night, you see myriads of stars spread across the sky. When astronomers look into the deepest reaches of the universe with powerful telescopes, they see myriads of galaxies, organized into large clusters and other structures. This might lead you to believe that the universe is composed mainly of galaxies, stars, gas and dust -- things that you can see. However, most astronomers believe that visible matter makes up only a small fraction of the mass of the universe. The majority of the universe is made of stuff we can't see -- so-called dark matter. Exactly what is dark matter? How can we detect it? What is its importance in the universe as a whole?
In this article, we'll examine these questions. We will look at the evidence for dark matter, how it can be detected and studied, the nature of dark matter, and how it helps define the structure and fate of the universe.
What is Dark Matter?
Simply put, dark matter cannot be seen by astronomers with telescopes. It doesn't emit or reflect enough light to detect, so it's not bright, like a star. Atoms, molecules and subatomic particles are dark matter. You and I are dark matter. Everything on Earth is dark matter. Planets, brown dwarf stars and black holes are dark matter. Basically, dark matter cannot be seen -- scientists can only estimate where it is based on gravitational effects on what they can see.
We can't see dark matter, but we can detect it by its effects on normal matter through gravity (rotation, gravitational-lensing) and by the X-rays emitted by hot, dark matter. So, what actually is dark matter? What is it made of? Let's take a look.
0ZoC2-_uVqo
http://science.howstuffworks.com/dictionary/astronomy-terms/dark-matter.htm
http://www.newscientist.com/article/mg21328465.800-mundane-dark-matter-may-lurk-in-starry-clusters.html