The Universe and All That’s In It

Unit 5: Sixth Grade

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

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.

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.

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.

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

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

GALAXIES AND OUR EXPANDING

UNIVERSE

Unit 6: Sixth Grade

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

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

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

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

Irregular Galaxies “Leftover” galaxies. They are not spiral,

nor are they elliptical galaxies.

They do not fit into any classification group.

Irregularly shaped

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?

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!

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!

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.

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