The Earth in Space

A) Earth's solar system is located in the Milky Way Galaxy. Our solar system in the Milky Way galaxy is located on the outer edge of the galaxy. The size of our galaxy is about 80,000-120,000 light years across but only 7,000 light years thick. For our solar system to complete one cycle/orbit around the Milky Way it takes about 200-250 million years while we are moving about 155 miles per second. "The universe is made up of voids and filaments, which can be broken down into super clusters, clusters, galaxy groups, and subsequently into galaxies." The age of the universe is about 13.7 billion years ago. The way we know that the universe was formed about 13.7 billion years ago was because of background radiation.

B) The definition of the Big Bang Theory is a theory that the universe originated sometime between 10 and 20 billion years ago from the cataclysmic explosion of a small volume of matter at an extremely high density and temperature. It is said that the universe was "significantly smaller than a pore on your skin" and has been increasingly expanding. As the universe expanded, clumps of matter would come together due to gravitaional attraction to form stars and galaxies.

C) The way we can tell the age of the universe is by cosmic microwave background. Cosmic microwave background is photons that have cooled as the universe has expanded and have stopped interacting. The Doppler Effect tells us that when sound moves it makes a different frequency when it's moving toward us and away from us. This has the same effect on light. By determining different frequencies on the cosmic microwave background we are able to tell if an object is moving toward us or moving away from us. The way we determine the different frequencies of light is because they show up as different colors.

Bibliography
http://www.learner.org/courses/physics/glossary/definition.html?invariant=cmb. Learner. Cosmic Microwave Background. 2010.
http://lcogt.net/education/article/milky-way-galaxy. Las Cumbres Observatory. The Milky Way Galaxy. 2012.




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