5.2.1 Unit Review: Rediscovering the Universe

​Unit Review: Rediscovering the Universe
5.2.1

By Caitlin Ford

​Key Concepts

• Types of galaxies

• Formation and evolution of galaxies

• Big Bang Theory and the fate of the universe

Vocabulary!

Vocab list available in edio.

Match

Match the following.

• a type of active galaxy

• an empty region in space

• the nearest galaxy to us

• our galaxy

quasar

void

Andromeda

Milky Way

• quasar

• void

• Andromeda

• Milky Way

Types of Galaxies

What 4 types of galaxies did Hubble identify?



What 2 other types of galaxies were discovered after Hubble's time?

Types of Galaxies

What 4 types of galaxies did Hubble identify?
- elliptical, spiral, barred-spiral, and lenticular



What 2 other types of galaxies were discovered after Hubble's time?
- barred lenticular and irregular

Match

Match the galaxy types.

lenticular

barred spiral

irregular

spiral

elliptical

• lenticular

• barred spiral

• irregular

• spiral

• elliptical

Formation of Galaxies

Explain the difference between the top-down model and the bottom-up model.



Explain the difference between the monolithc collapse model and the hierarchical model.



Which model is the most widely accepted today?

Formation of Galaxies

Explain the difference between the top-down model and the bottom-up model.
- Top-down states that a large cloud of gas and dust collapsed under gravity and compressed into galaxies. Bottom-up states galaxies formed from small clumps of matter compressed by gravity over time.

Explain the difference between the monolithic collapse model and the hierarchical model.
- Monolithic: all galaxies came from a single source of material. Hierarchical: clumps of matter gained mass and grew into large structures.

Which model is the most widely accepted today?
- hierarchical model!

Hierarchical model explains:

- the variety of galactic shapes and sizes

- the presence of a supermassive black hole in the center of most galaxies

- the large-scale structure of the universe

Dark Matter

What is dark matter?



What is the cold dark matter model?

Dark Matter

What is dark matter?
- invisible matter whose properties are not known



What is the cold dark matter model?
- a revised version of the hierarchical model that takes into account the role of dark matter in the formation of galaxies

Dropdown

The ​

Select answer

model explains the variety of galactic shapes and sizes.

The Big Bang Theory

What is inflation?



What three pieces of evidence support the Big Bang Theory?

The Big Bang Theory

What is inflation?
- the sudden expansion of a single point at the beginning of the universe



What three pieces of evidence support the Big Bang Theory?
- galaxies are moving away from each other (redshift), cosmic microwave background radiation, older stars are made of heavier elements

Timeline

1. Rapid inflation

2. Protons, electrons, and neutrons form

3. Hydrogen and helium form

4. Cosmic microwave background radiation

5. Stars and galaxies form

6. Clusters and superclusters

Fate of the Universe

What is a void?



How big is the observable universe?



What is the ultimate fate of the universe?

Fate of the Universe

What is a void?
- empty regions between superclusters


How big is the observable universe?
- 93 billion light years across


What is the ultimate fate of the universe?
- Big Freeze! The universe will keep expanding, galaxies will grow further apart, stars will die out, and all matter will fall into black holes.

Reorder

Order the events of formation according to the Big Bang Theory.

• inflation

• protons, electrons, neutrons

• molecules

• stars and galaxies

• clusters and superclusters

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Multiple Choice

What force could be capable of halting and reversing the expansion of the universe?

• friction

• electromagnetic force

• magnetic force

• gravitational force

Hotspot

Where on Hubble's galaxy classification system would we put the Milky Way?

Great job!

During our next class, we will play a review game for more review.

Completed notes are available on the course home page. The link will take you to the notebook!

If you feel confident right now, go ahead and take the test!

If you need any help, send me an edio chat :)