1. By Jaedyn Waggoner. Block C. Mr. Horton. Science 9 THE UNIVERSE

2. THE BIG BANG THEORY Happened approximately 13.5 billion years ago The Big Bang was caused by the density of the compressed galaxies. It was in a very high density state, then it expanded. After the beginning expansion, it cool to let subatomic particles and later on, simple atoms to form.

3. EXPANDING UNIVERSES There are 3 types of universes, open, flat, and closed. Open universes expand forever. Flat universes expand forever, but the rate that it expanded at would eventually slow down to zero after an infinite amount of time. Closed universes eventually stop expanding and recollapse on itself, potentially causing another big bang. In all three types of universes, the expansion does slow eventually, and the cause of them slowing is of course, gravity.

4. ASTRONOMER RESEARCH What is an astronomer? - an astronomer is a scientist who studies celestial bodies i.e. black holes, planets, stars, asteroids, comets, nebulae, and galaxies (space). Astronomers use telescopes and radio signal type technologies to better understand our universe and how it works. It is important to know about our universe because if we didn’t, we wouldn’t know the precautions that come with meteors and asteroids and such.

5. THE GALAXY Galaxies are thought to be formed as the result of little quantum fluctuations from the aftermath of the Big Bang. They gain mass by clustering and merging with one another. There are 4 types of galaxies, Elliptical, Spiral, Lenticular, and irregular. Elliptical galaxies don’t have very much gas and dust. Because gas and dust are found in clouds that stars are born from, there are not many young stars in elliptical galaxies. They contain mostly old, red stars. Spiral galaxies have two very distinct regions. The middle – the disk of the galaxy – contains the spiral arms. The disk is where many stars are born, and it has a lot of gas and dust. Most of the stars are young, blue Population I stars. Type C spiral galaxies have the most amount of gas and dust. Lenticular galaxies have central bulges and disks, but lack spiral arms. It’s quite easy to mistake a lenticular galaxy for an elliptical galaxy, but only if the disk is faint. Galaxies that don’t fit into the spiral or elliptical galaxies are considered irregular galaxies. They have a wide variety of shape and characteristics, and are frequently the result of when two or more galaxies collide.

6. EDWIN HUBBLE & GEORGES LEMAÎTRE Edwin Hubble was an American Astronomer who helped in creating the theory about extragalactic astronomy. He also provided evidence that many things back then called Nebulae were actually galaxies past the Milky Way. This theory had been previously discovered by the Belgian Priest and Astronomer, Georges Lemaître, but because it was written down and recorded in an illegible notebook, the theory stays called “Hubble’s Law”. The Hubble’s Law is the observation that objects seen and observed far out in space are often found to have a Doppler Effect that could be considered relative velocity far from Earth and that this Doppler-Effect-measured velocity of certain galaxies moving away from Earth is proportional to their distance from Earth for galaxies that are up to a hundred or so megaparsecs away. The Hubble Law is the first observational basis for the expansion of space paradigm and it is one of the most cited theory for the Big Bang model.

7. RED SHIFT ANALYSIS Redshift is when any electromagnetic radiation from an object is increased in wavelength or shifted to a certain point in the spectrum. Whether the radiation is on the visible spectrum or not, redder means the wavelength has increased. Certain redshifts are an example of the Doppler effect. Cosmological redshift is caused by the expansion of the universe and distant light sources (usually more than a couple million light years away).

8. YOUTUBE VIDEO https://www.youtube.com/watch?v=mYhy7eaazIk