Models to visualize size and distance in the universe

# JOB 4: A scale for the whole Universe: The Milky Way galaxy a size E ball

Although there are 100 to 200 billion other galaxies in the Universe, the galaxies are relatively close together. The next scale factor brings the whole visible universe into the model, by letting a sphere of size E (4mm diameter) represent the whole Milky Way galaxy.

 Step 1. Establish a scale for your JOB 4 model Make a ratio of the actual diameter of the Milky Way galaxy to the diameter of the model of the Milky Way galaxy (Be sure units are the same in the numerator and denominator before canceling them) SCALE = ____________ / _____________    =    [ ___________ ] : [1]

 The SCALE of this model is: [ _____________ ] : [1] The Scale factor is _________________

In your JOB 4 scale model, the size of the Milky Way galaxy will be the size of the E sphere. All other distances and sizes will be shrunk in the same proportion, that is, their actual size divided by the scale factor that you have calculated.
 Question (A): How far is it to the Andromeda galaxy in your JOB 4 model? The distance in the JOB 4 model will be the actual distance to Andromeda, divided by the scale factor. Solution: The distance to Andromeda in your model is: _____________ / ___________ = _________

 In your JOB 4 model, the distance to the Andromeda galaxy will be _____m or ____cm. Name an object that is approximately this big ________________

 Question (B): The farthest object observed so far (a quasar) is over 12 billion light years away. How far is it to that quasar in your JOB 4 model? Distance to the quasar in your model is the actual distance to the quasar, divided by the scale factor. Solution: Distance to the quasar in your model is: _____________ / ___________ = _________

 In your JOB 4 model, the distance to the farthest object ever observedis________m; or ____ times the length of a football field.

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