The Big Bang The Big Bang Cosmology The
The Big Bang
The Big Bang ØCosmology – The study of the structure and evolution of the universe. ØBig Bang Theory – The universe was very hot and small. Billions of years ago it violently exploded and has been expanding and cooling ever since. ØAstronomers estimate the universe to be about 13. 7 billion years old.
The Big Bang Proving the Big Bang: 1. Moving Galaxies: Galaxies are moving away from each other. ØHubble’s Law – The farther away the galaxy is, the faster it is moving away from us. This supports the Big Bang. 2. Cosmic background Radiation – Mysterious energy glow picked from a telescope in 1965. Turns out it was leftover thermal energy from the Big Bang.
The Big Bang ØThis glow seemed to come from all directions like it came from a central source. 3. Age of the Universe – Astronomers can measure approximately how fast the universe is expanding. ØBetween measuring the movement of galaxies and cosmic background radiation astronomers can estimate the age of the universe to be 13. 7 billion years old.
The Big Bang Formation of the Solar System: ØSolar Nebula – large cloud of dust and gas that formed our solar system. (about 5 billion years ago) ØAs it spun, it flattened like a disk and gravity pulled the solar nebula together to form our sun.
The Big Bang ØGas and dust gathered together in the outer parts of the rotating disk to form planetisimals. ØOver time, these planetisimals formed the planets
The Big Bang
The Big Bang Galaxies: Group of stars, star systems, star clusters, dust, and gas bound together by gravity. ØSpiral – Bulge in the middle with arms that curve outward. Most new stars are found in the arms. ØElliptical – A round flattened ball. Contains mostly old stars. ØIrregular – No certain shape. Contain many bright young stars and much dust and gas.
The Big Bang The Future of the Universe: ØNo one knows for sure what will happen to the universe. ØIt seems to be in constant motion ØAstronomers think it will continue to expand.
The Big Bang ØDark matter – does not give off light so can not be seen. Makes up 23% of the universe ØGalaxies seem to be moving apart faster than they used to. Astronomers think this is because of dark energy. Most of the universe is made up of dark matter and dark energy
The Big Bang
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