Friday, January 8, 2010

Dark Matter

 This is the oral report I have to give on Monday! READ IT! I want criticism. (Do we just say the ten facts or work them in???)

Dark Matter is a theoretical form of matter that is invisible, but whose presence can be inferred from gravitational effects on visible matter. In terms that most people can understand, that means that nobody is really sure that dark matter is actually there, but that there's something in all that space. Dark matter changes the orbits of planets and galaxies. Fritz Zwicky presented the idea in 1934 as a reason for the Universe being HUGE but only 4.6% of it being matter. He called this invisible matter 'dark matter' because it is completely transparent, but space is black, meaning that the matter would have to be dark. Most dark matter in the universe is non-baryonic, which basically means that it has no atoms. Non-baryonic dark matter didn't contribute to the formation of the elements during the Big Bang, while baryonic dark matter, which has atoms, did. There are three types of dark matter in the universe: cold dark matter, hot dark matter, and a combination of the two, warm dark matter. It's cold dark matter that's non-baryonic. Hot dark matter is baryonic, and warm dark matter is mostly non-baryonic, but it has a few atoms. If you're really rich and have an extremely powerful telescope, an easy way to never be bored is to look at something in the sky and determine if it has any dark matter. All you have to do is calculate the mass to light ratio by dividing the total mass by the luminosity, then determine whether it's a high number. The baryonic dark matter in the universe is made of Weakly Interacting Massive Particles (or WIMPs). A large number pass thorough Earth every second. Dark matter is a huge part of the popular British book series His Dark Materials, more commonly known as the Golden Compass Series. Although dark matter is the most widely accepted theory for gravitational pulls on orbits, several other theories have been proposed. However, none of these have as much respect in the scientific community as Dark Matter. 
 My interesting facts:  
 1. Dark matter changes planet's and galaxy's orbits.
 2. Dark matter fills up the nothingness in space. 
 3. Fritz Zwicky (that name's interesting in itself) discovered dark matter in 1934. 
 4. The Universe is only 4.6% matter; the rest is all dark matter
 5. Dark matter got it's name because it's transparent in the darkness of space. 
 6. Most dark matter is atom-free.
 7. You can determine whether an object has dark matter by calculating it's mass to light ratio.
 8. Baryonic dark matter is made up of WIMPS 
 9. A large amount of dark matter passes through Earth every second. 
10. Dark matter has a central role in the popular British book series His Dark Materials, where it is a conscious being. 

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