We have optional homework for Astronomy class. I’m not even sure when it’s due. This teacher has been somewhat fuzzy on these issues; for example, the syllabus says that attendance is part of our grade, but he has yet to take roll. Anyway…
A “scale model” in this case is when you compare something that is too large to be comprehended to something that really relates the size. My favorite example from last night is one regarding the number of stars in the universe.
Scientists estimate that there are 1021 stars in the universe. That’s 1,000,000,000,000,000,000,000. Can you really get your head around this number? No. Hence the scale model:
Know that there are 100,000 to 150,000 hairs on an average human head. Let’s just say that there are 100,000 to account for bald people. There are roughly 6,374,589,428 on the planet, and we’ll round that to a even 6 billion.
Take all of the people and shave all of the hair from their heads. Collect all of the hair and chop each piece into, literally, a million pieces. Do you now have more pieces of hair or more stars? Look at the math:
105 hairs * 6109 people * 106 pieces= 61020 pieces of hair.
There are about 4*1020 more stars than hairs. Almost double. Cool, huh?
