Astronomy 10 Spring 2000

Worksheet #1

1. Let’s practice with units (dimensions) and estimation:

a) when you look at the Sun (through appropriate filters!), how far back in the past are you seeing it? (1 AU = 1.5x10¹¹ m, speed of light=3x10⁸ m/s)

b) if we scale up an atomic nucleus (R=10^-15 m) to the size of the head of a BB (R=1mm), how big would an atom (R=10^-10 m) be?

c) How many AU are there in a light year?

d) How many drops of water are there in all the oceans?

2. Would the constellations look the same from Neptune? From a star 10 light years away? From a star 1000 light years away?

3. Organize a demonstration of retrograde motion using people in the classroom.

4. Divide up into opposing sides, and argue the following propositions (using evidence you could gather yourself in modern times):

a) the Earth is spinning

b) the Earth is going around the Sun

c) the Earth is round

d) the stars are very far away