Date: Tue, 22 Sep 2009 15:58:06 -0500 (CDT) From: Mark Jacobson To: 810-025-01-fall@uni.edu Subject: [810-025-01-FALL] Exponential Growth and Exponential Decay... Hello 025 students, Folding a sheet of paper in half 50 times exercise summary. 2 ^ 50 1125899906842624 sheets of paper you would have after doubling the number of sheets 50 times, if you start with 1 sheet. (Or fold one sheet of paper in half 50 times, if it were possible!) 2 ^ 50 / 500 2251799813685.24800000000000000000 number of reams of paper, where a ream of paper has 500 sheets, which is the typical pack size. 2 ^ 50 / 500 * 2 4503599627370.49600000000000000000 2 inches is about the thickness of 500 sheets or one ream of paper, so this number is the inches thick the entire pile of sheets is. 4503599627370.49 / (12 * 5280) 5,280 feet per mile * 12 inches/foot 71079539.57339788510101010101 is the divisor. 71,079,539.6 miles is a pretty good estimate for the height of the stack of paper. Distance of the moon from the earth: 238,857 miles "The average centre-to-centre distance from the Earth to the Moon is 384,403 kilometres (238,857 mi), about thirty times the diameter of the Earth." Distance of the sun from the earth: 92,580,000 miles "The average distance from the Sun to the Earth is 1.496 x 1011metres (149 million kilometres or 92.58 million miles)." 92,580,000 miles from the earth to the sun 71,079,540 miles for the paper's height 71,079,539.6 miles is a pretty good estimate for the height of the stack of paper. We will use the Dictionary sometime in class to illustrate exponential decay concept and the binary search for a secret word in an unabridged dictionary. Mark