1. Homework: Due at Midnight
Google classroom

2. Learning Goals: I will:
4. Complex Knowledge: demonstrations of learning that go aboveand above and beyond what was explicitly taught. 3. Knowledge: meeting the learning goals and expectations. 2. Foundational knowledge: simpler procedures, isolated details, vocabulary. 1. Limited knowledge: know very little details but working toward a higher level.
I will:
understand the properties of different types of galaxies.
understand how the universe came to be what we observe today.
understand how astronomers use astronomical objects (standard candles)
as a distance ladder to estimate the size of the universe and to measure large
distances in the universe.
understand how astronomers determine the age and size of the universe?.

3. What you were supposed to learn from the “classifying galaxies” activity
Elliptical galaxies: contain mostly old stars, with very little gas and dust found between stars. Since new stars form from clouds of interstellar gas and dust, elliptical galaxies lack the raw ingredients to make new stars.
Spiral galaxies: on the other hand, have a mix of young and old stars. Interstellar gas and dust fill the disks of spiral galaxies, and new star formation continues to take place in their disks.
Irregular galaxies: appear chaotic, and often have many bright, young stars, the result of recent bursts of intense star formation.
Do Irregular Galaxies have gas and dust clouds?

4. Modeling the Movement of Galaxies
Instructions and Questions are on Google Classroom
Work in pairs
A pair is 2 people
Only one person blow up the balloon. – obviously.

5. Modeling the Movement of Galaxies
Inflate the balloon until it has a circumference of about 40 cm. Do not tie the balloon.
Draw five dots, with the sharpie, on the top of the balloon. The dots should be in a random pattern at various distances from each other.
Pick one dot to represent your Home Galaxy. Measure and record the distance to the other dots (which are other galaxies) from your Home Galaxy. – Record your data
Inflate the balloon so its circumference increases by an additional 8 cm.
Record the new distances of the dots (galaxies) from your Home Galaxy.
Calculate the difference between starting distance and current distance from home galaxy
Inflate the balloon another 8 cm.
Record the new distances of galaxies from your Home Galaxy.
Calculate the difference between original starting location and its final location

8. I have already created this for you on google classroom
(the instructions are also on google classroom)
Galaxy
Distance
New
Distance 1
Amount
Of change
(Distance-New Distance 1)
Distance 2
Amount of change (Distance-New Distance 2)
Home Galaxy
(*)
0 cm
Closest
2nd Closest
3rd
Closest Galaxy
4th closest

9. Conclusion: (Answer in your science journal – underneath your data table)
As the balloon was inflated what happened to the distances of the other galaxies from your Home Galaxy?
Did all the galaxies move away at the same rate?
Which ones moved away faster? Which slower?
If a different galaxy was selected as the Home Galaxy would the results be the same?
Why or Why Not?
What do you think this model represents?
If your observed results were representative of what really happens in the universe, what should the effect be that we see in the spectrum of the light from distant galaxies?
If you started with a fully expanded balloon (ie. The Universe), and ran this experiment in reverse, what would happen to the dots? (ie. The galaxies)
In this experiment your breath caused the balloon to expand, what causes the actual Universe to expand?