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Galaxies
Review of three galaxies
Term | Definition |
---|---|
Milky way | Spiral shaped galaxy that we live in |
Galaxy | A massive collection of stars, dust and gas held together by gravity |
Approximate age of the universe | 13.5- 14.5 billion years |
Gravity | A pull force that holds the planets in orbit around the sun |
Stellar Region | group of neighboring stars |
Andromeda | Closest galaxy to the milky way. It is 2 Billion light years away |
Fusion | Combining two small nuclei to form a large nucleus. |
Big Bang Theory | The accepted scientific theory of how the universe was formed from a big explosion which caused matter to fly apart |
E=mc2 | Albert Einstein's equation which explains that you only need a small amount of matter to make lots of energy. |
Hubble's Law | A law that supports that the universe is expanding. It states that objects further away move away faster and appear red; Objects that are closer appear blue. |
Doppler Effect (Redshift) | Objects moving toward us look blue, have short wavelengths, high energy, and high frequency Objects moving away from us look red, have long wavelengths, low energy, and low frequency |
Hydrogen | First element created 1 sec after the big bang. Only element that can withstand such extreme temperature. It is the simplest to make with 1 proton, 1 neutron, and 1 electron. |
Helium | This element formed 3 minutes after the big bang. it is the second element |
Spiral Galaxy | This type of galaxy has a lot of gas and dust and is the youngest galaxy |
Elliptical Galaxy | This type of galaxy has no gas and dust, has a sphere shape, is the oldest galaxy, and is made of all old stars |
Irregular Galaxy | This type of galaxy, had no definite shape, little dust and gas, and have mostly old, but some young stars. |
As the universe expands... | ...it cools and decreases in energy |
Hydrogen, Helium, Lithium | 1st 3 elements created after big bang |
Strong Nuclear Force | What is weakened by extreme heat? |
Hydrogen & Helium | What are the most abundant (common) elements? |
Heavy Elements | What type of elements form under cooler temperatures? |
Gamma Radiation | What type of radiation was evident at the Big Bang? |
Microwaves | What type of radiation is evident today? |
Decreases | The universe cools as it expands. What happens to energy as the universe cools? |