1. IOT POLY ENGINEERING 2-3 COMMUNICATION TECHNOLOGY October 21, 2010 "In the deepest sense the search for extraterrestrial intelligence is a search for ourselves." - Carl Sagan Are you smarter than an extraterrestrial space alien?

2. IOT POLY ENGINEERING 2-3 As we go through this lesson, you should letter your answers to these questions.

3. IOT POLY ENGINEERING 2-3 "In the deepest sense the search for extraterrestrial intelligence is a search for ourselves." - Carl Sagan

4. This is the radio telescope located at Arecibo, Puerto Rico. The facility is a part of the NSF operated by Cornell University.

5. IOT POLY ENGINEERING 2-3 The Arecibo message was composed by Professors Frank Drake and Carl Sagan of Cornell University. The message was beamed into space a single time via frequency modulated (FM) radio waves at a ceremony to mark the remodeling of the Arecibo radio telescope on 16 November 1974. It was aimed at the star cluster M13 about 25,000 light years away. M13 is a large collection of stars that was available in the sky at the time and place of the ceremony. The message was transmitted at a frequency of 2380 MHz and modulated by shifting the frequency by 10 Hz, with a power of 1000 kW. The "ones" and "zeroes" were transmitted by frequency shifting at the rate of 10 bits per second. The total broadcast was less than three minutes.

6. IOT POLY ENGINEERING 2-2 Reminder from last week’s lessons: Radio: Pulse Modulation: turn the voltage (sine wave) on/off (Morse Code) Amplitude Modulation: vary the amplitude (peak-to-peak) voltage Frequency Modulation: vary the frequency (speed) PM AM FM Encoder: Devices that convert sound and information into a modulated sine wave

7. IOT POLY ENGINEERING 2-3 00000010101010000000000001010000010100000 00100100010001000100101100101010101010101 01001001000000000000000000000000000000000 00001100000000000000000001101000000000000 00000001101000000000000000000101010000000 00000000000111110000000000000000000000000 00000001100001110001100001100010000000000 00011001000011010001100011000011010111110 11111011111011111000000000000000000000000 00100000000000000000100000000000000000000 00000000100000000000000000111111000000000 00001111100000000000000000000000110000110 00011100011000100000001000000000100001101 00001100011100110101111101111101111101111 10000000000000000000000000010000001100000 00001000000000001100000000000000010000011 00000000001111110000011000000111110000000 00011000000000000010000000010000000010000 01000000110000000100000001100001100000010 00000000011000100001100000000000000011001 10000000000000110001000011000000000110000 11000000100000001000000100000000100000100 00000110000000010001000000001100000000100 01000000000100000001000001000000010000000 10000000100000000000011000000000110000000 01100000000010001110101100000000000100000 00100000000000000100000111110000000000001 00001011101001011011000000100111001001111 11101110000111000001101110000000001010000 01110110010000001010000011111100100000010 10000011000000100000110110000000000000000 00000000000000000001110000010000000000000 01110101000101010101010011100000000010101 01000000000000000010100000000000000111110 00000000000000011111111100000000000011100 00000111000000000110000000000011000000011 01000000000101100000110011000000011001100 00100010100000101000100001000100100010010 00100000000100010100010000000000001000010 00010000000000001000000000100000000000000 100101000000000001111001111101001111000 This is the binary code sent from Arecibo observatory on 16 November 1974. ?

8. IOT POLY ENGINEERING 2-3 Cryptography (or cryptology; from Greek κρυπτός, kryptos, "hidden, secret"; and γράφω, gráphō, "I write", or -λογία, -logia, respectively) is the practice and study of hiding information. Modern cryptography intersects the disciplines of mathematics, computer science, and engineering. Applications of cryptography include ATM cards, computer passwords, and electronic commerce.

9. IOT POLY ENGINEERING 2-3 As a clue to decoding the message, count the number of “ones” and the total number of binary digits, “ones” and “zeros”. Also count the number of rows and columns.

10. IOT POLY ENGINEERING 2-3 The binary digits form a pattern of 41 columns by 41 rows,.. less two binary digits at the end. There are a total of (41)(41) =1681 less 2, or 1679 binary digits. Of the 1679 binary digits, there are 397 ‘ones’ and 1282 ‘zeros’. 1679 is the product of two prime numbers: 23 and 73. 397 is a prime number. There are two ways to arrange the 1679 binary digits as a pattern of rows and column using prime numbers: a pattern of 23 rows deep by 73 columns wide, or a pattern of 73 rows deep by 23 columns wide.

11. IOT POLY ENGINEERING 2-3 There are two ways to arrange the 1679 binary digits as a pattern of rows and column using prime numbers: a pattern of 23 rows deep by 73 columns wide, or a pattern of 73 rows deep by 23 columns wide.

12. IOT POLY ENGINEERING 2-3 There are two ways to arrange the 1679 binary digits as a pattern of rows and column using prime numbers: a pattern of 23 rows deep by 73 columns wide, or a pattern of 73 rows deep by 23 columns wide. You may now begin to decode the message here in class, and complete it at home for homework.

13. IOT POLY ENGINEERING 2-3 There are two ways to arrange the 1679 binary digits as a pattern of rows and column using prime numbers: a pattern of 23 rows deep by 73 columns wide, or a pattern of 73 rows deep by 23 columns wide. The next slide shows the decoded message.

14. IOT POLY ENGINEERING 2-3 There are two ways to arrange the 1679 binary digits as a pattern of rows and column using prime numbers: a pattern of 23 rows deep by 73 columns wide, or a pattern of 73 rows deep by 23 columns wide.

15. IOT POLY ENGINEERING 2-3 "Here is how we count from one to ten. Here are five atoms that we think are interesting or important: hydrogen, carbon, nitrogen, oxygen and phosphorus. Here are some ways to put these atoms together that we think interesting or important - the molecules thymine, adenine, guanine and cytosine, and a chain composed of alternating sugars and phosphates. These molecular building blocks are put together to form a long molecule of DNA comprising about four billion links in the chain. The molecule is a double helix. In some way this molecule is important for the clumsy looking creature at the center of the message. That creature is 14 radio wavelengths or 5 feet 9.5 inches tall. There are about four billion of these creatures on the third plant from our star. There are nine planets altogether, four big ones toward the outside and one little one at the extremity. This message is brought to you courtesy of a radio telescope 2,430 wavelengths or 1,004 feet in diameter. Yours truly."