The Universe and All That’s In It

1. Unit 5: Sixth Grade The Universe and All That’s In It

2. How big is space? • How big is space? • That is a question man has been asking since the beginning of time. • When your grandparents were in school, it was thought that the Universe was very small, perhaps only 5000 light years across. • A light-year is a unit of distance. It is the distance that light can travel in one year • It is about 6 trillion miles

3. Millions, Billions and Trillions • One million is a thousand thousands. • One million is a 1 with six zeros after it, denoted by 1,000,000. • One million seconds is about 11 and a half days. • One million pennies stacked on top of each other would make a tower nearly a mile high. • If you earn $45,000 a year, it would take 22 years to amass a fortune of one million dollars. • One million ants would weigh a little over six pounds.<\li> • One million dollars divided evenly among the U.S. population would mean everyone in the United States would receive about one third of one cent.

4. Millions, Billions and Trillions • Next up is one billion: • One billion is a thousand millions. • One billion is a 1 with nine zeros after it, denoted by 1,000,000,000. • One billion seconds is about 31 and a half years. • One billion pennies stacked on top of each other would make a tower almost 870 miles high. • If you earn $45,000 a year, it would take 22,000 years to amass a fortune of one billion dollars. • One billion ants would weight over 3 tons - a little less than the weight of an elephant. • One billion dollars divided equally among the U.S. population would mean that everyone in the United States would receive about $3.33.

5. Millions, Billions and Trillions • After this is a trillion: • One trillion is a thousand billions, or equivalently a million millions. • It is a 1 with twelve zeros after it, denoted by 1,000,000,000,000. • One trillion seconds is over 31 thousand years. • One trillion pennies stacked on top of each other would make a tower about 870,000 miles high - the same distance obtained by going to the moon, back to earth, then to the moon again. • One trillion ants would weigh over 3000 tons. • One trillion dollars divided evenly among the U.S. population would mean that everyone in the United States would receive a little over $3000.

6. How Big is The Universe? • 500 years ago it was thought that the Universe was only a little bit bigger than the Earth. • In modern times, with the power of technology, we are finally starting to grasp the immense size of the Universe, and it is much bigger than anyone could have ever imagined. • http://www.kidsastronomy.com/space_size.htm

7. Hierarchy of the Universe • Name • Street Address • City • State • Country • Planet(s) • Terrestrial /Inner Planets---Mercury, Venus, Earth, Mars • Gaseous/Outer Planets----Jupiter, Saturn, Uranus, Neptune, and Pluto the Dwarf • Solar System---planets, Sun, asteroid belt • Galaxy---The Milky Way • Universe

8. Unit 6: Sixth Grade Galaxies and our expanding Universe

9. Galaxies • Large groups of stars, dust and gas are called galaxies. • Nebulas= large clouds of dust and gas • Galaxies come in a variety of shapes and sizes. • The largest galaxies contain trillions of stars

10. Types of Galaxies • There are many types of galaxies. • Edwin Hubble, the man who first declared that the Milky Way is not the only galaxy in our universe classified galaxies, mostly by their shapes in the 1920’s • Galaxies are classified as: Spiral, Elliptical and Irregular

11. Spiral Galaxies • Spiral Galaxies have a bulge at the center, and spiral arms. • The arms are made of gas, dust and new stars. • Contain many nebulae that are forming new stars • The Milky Way (our galaxy) is believed to be a spiral galaxy

12. Elliptical Galaxies • Elliptical galaxies have very bright centers and little dust and gas. • They have no “arms” • Made of mostly old stars • Look like massive blobs of stars

13. Irregular Galaxies • “Leftover” galaxies. • They are not spiral, nor are they elliptical galaxies. • They do not fit into any classification group. • Irregularly shaped

14. Formation of the Universe • To understand how the galaxies are moving, imagine a loaf of raisin bread before it is baked. • Inside, each raisin is a certain distance from another raisin. • Why happens as the dough warms and rises?

15. Raisin Bread and the Universe • As the dough warms and rises, it expands, and all of the raisins begin to move further apart. • No matter which raisin you observe, the other raisins are moving farther away from it!

16. Raisin Bread and the Universe • Scientists believe that our universe, like the rising dough, is expanding. • Think of the raisins as galaxies. • As the universe expands, the galaxies move farther apart!

17. The Big Bang Theory • Leading scientific theory about the formation of the universe. • 13.7 billion years ago, all contents of the universe were compressed under extreme pressure, temperature, and density in a tiny spot. • Then, the universe rapidly expanded after a tremendous explosion. • The explosion continues to cause the universe to expand.

18. A Forever Expanding Universe • As our galaxies move farther apart, they get older and stop forming stars. • Therefore, stars will age and die, and the universe will get cold and dark after many billions of years. • However, the universe will continue to expand forever