Fix the solutions and have all copies of orig HW *and* solns match

Large Numbers: Models for Large Time Scales
Working in groups of two allowed and encouraged

Some Facts to use:
  1. Age of the universe: about 13.7 billion years ago
  2. Age of planet Earth: about 4½ billion years ago
  3. Earliest life forms on Earth: about 3.7 billions years ago
  4. Dinosaurs: lived roughly between 230 and 65 million years ago; let's use 150 million years ago (roughly the middle of the period)
  5. Family Hominidae emerges: about 6½ million years ago
  6. Genus Homo emerges: about 2½ million years ago
  7. "Anatomically modern humans [homo sapiens sapiens] appear in the fossil record in Africa about 130,000 years ago" [Wikipedia]
  8. Agriculture emerges ~10,000 years ago
  9. Industrial revolution starts: about 200-250 years ago
  10. First humans to walk on the moon: about 39 years ago
  11. World Wide Web emerges from labs into wider public domain: about 15 years ago

Assignment: Your next assignment with large numbers will probably be an environmental one related to the total amount of energy typical US households use per year, or the like. So here is one more exercise to practice and show your quantitative literacy facility with large numbers and metric/English conversions (as well as scaling).

Imagine you are drawing a huge, scaled down "time line" along the highways of the US, to represent the Grant Time Line with the events A through K. above. Your Starting Mark marks the beginning of the Universe, 13.7 billion years ago. With a billion years being represented (see below) by 100 kilometers (km) in this huge timeline, this means the mark for "today" and the mark for the "Big Bang" will be 1,370 km apart. The Earth was "born" roughly 4.5 billion years ago, so its position on the Grand Timeline is 450 km away from the "Today" mark. Fill out the rest of the chart; a few boxes have been filled out to help you get started (you can use maps.google.com for ideas for filling out the last column) Also use appropriate units; avoid writing "0.000378787879 miles" for 3 feet, etc.

Using the scale of "100 km = 1 billion years"
 In metric systemIn English unitsExample of such a distance
1. Big Bang 1,370 km~850 miles Straight line from Salsibury to a point
somewhere between Chicago IL and Dubuque IA
2.Planet Earth forms 450 km   
3. Earliest life on Earth   
4. Dinosaurs   
5. Hominidae    
6. Homo   
7. Modern Humans emerge   
8. Agriculture    
9. Industrial revolution    
10. Moon walk    
11. Public WWW    

Show all your work:
1. If 1 billion years corresponds to 100km then 13.7 billion years corresponds to (13.7)·(100km) = 1,370 km. I typed "1370 km in miles" into Google Calculator and got "1,370 kilometers = 851.278533 miles" and then rounded to 850 miles. I then used maps.google.com and found about 800 miles from Salisbury MD to Chicago IL but that is not a straight line (it is driving) so a straight line 800 miles long would take you a bit past Chicago if you started at Salisbury. Then I added 50 miles visually, and it's roughly between the two cities mentioned above.

2. Fill this and subsequent parts in..]