Universe Notes

History of the Universe

KEY Terms

The Universe- Space and all the matter/ energy in it.

Cosmology- Study of the origin of the universe

Astronomical Unit- Average distance between Earth and the Sun (93 million miles), it takes lights 8 minutes to cover this distance.

Light Year-Distance light travels in a year. (6 trillion miles)

Multiple Choice

What best defines the Universe?

• Just space

• Space and all the matter and energy in it.

• The matter and energy contained in the world.

• Just energy

Open Ended

How many minutes does it take for light to cover one astronomical unit?

Edwin Hubble

• Determined that other galaxies exist besides the Milky Way.

• Observed galaxies were moving away from each other.

Hubble's Law- the farther away a galaxy is, the faster it is moving away from us (supports the big bang theory).

Multiple Choice

What theory does Hubble's Law support?

• Big Bang theory

• Scientific Method

• Binary System (theory)

• Galaxy theory

Dropdown

Edwin Hubble observed that ​

Select answer

were movin​g​

Select answer

from each other. This proves the ​

Select answer

theory.

Big Bang Theory

- 13.8 billion years ago.
- Universe began as a small spec of dust and expanded rapidly into what we see today.
- Based on the observation galaxies are moving away from each other.

​Proves the Universe is expanding.

Dropdown

Objects moving away from us are ​

Select answer

objects moving towards us are ​

Select answer

.

​More proof of the history of our Universe.

Galaxy

Large assemblage of stars (often gas and dust), typically containing billions of member stars.
Star: large hot ball of gas which generates energy.

- Around 100 billion galaxies in the universe.
- Held together by gravitational attraction of stars.
- Formed around 200 million years after the "Big Bang"

Three major types:
1.) Spiral
2.) Elliptical
3.) Irregular

Categorize

Options (12)

Arms that curve away from center.

Sphere shape

No definite shape.

Arms that are tightly wound.

Examples include the Milky Way and Andromeda.

Typically contain older stars.

Can range from nearly spherical to more elongated shapes.

Typically smaller than spiral and elliptical galaxies.

Smaller than other galaxies

Faint and contains few stars.

Almost no gas or dust between stars.

Spiral shaped

Sort the following based on the type of galaxy that is described.

Spiral

Elliptical

Irregular

Constellation

• Group of stars that form a pattern in the sky.

• Stars are far away from each other in space.

• Patterns of constellations are dynamic; therefore, the constellations of 100,000 years ago are quite different from today's.

Open Ended

Why is it not possible to see all constellations at once?