INVITATION TO CYBERSECURITY 14 263 = 23 x 260 260 has six groups of ten binary places (60 ÷ 10 = 6). Therefore, we need six groups of three decimal places for a total of eighteen (6 x 3 = 18). 260 ≈ 1018 Then we can calculate 23: 23 = 8 Therefore, the final approximation is: 8 x 1018 = 8,000,000,000,000,000,000 This is eight quintillion, an enormous number approximately equal to the number of the grains of sand on Earth. Note that the number of people and the grains of sand, 233 and 263, are different by a factor of 230. This means that there are a billion grains of sand for every person on Earth. 2.1.4 Computer Illustration “‘And what is the use of a book,’ thought Alice, ‘without pictures or conversations?’” - Alice’s Adventures in Wonderland by Lewis Carroll To illustrate how computers work at the most basic level, and to show how it is human intelligence that extracts the meaning from their calculations, suppose someone needs help deciding where to go on his next vacation. He has determined he wants to go someplace where he can see exotic animals in their natural habitat, or someplace where he can eat at nice restaurants and collect sea shells. Figure 2.4 shows a very simple computer that helps solve this problem. Figure 2.4 A simple computer.
RkJQdWJsaXNoZXIy MTM4ODY=