Arecibo Message
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Arecibo_Message".

This is the message with color added to highlight its separate parts. The actual binary transmission carried no color information.
The Arecibo message as decoded into 23 rows and 73 columns.

The Arecibo message was beamed via frequency modulated radio waves into space at a ceremony to mark the remodeling of the Arecibo radio telescope on 16 November 1974.1 It was aimed at the globular star cluster M13 some 25,000 light years away because M13 was a large and close collection of stars that was available in the sky at the time and place of the ceremony.2 The message consisted of 1679 binary digits, approximately 210 bytes, transmitted at a frequency of 2380 MHz and modulated by shifting the frequency by 10 Hz, with a power of 1000kW.1 The cardinality was chosen because it is a semiprime3 (the product of two prime numbers), to be arranged rectangularly as 73 rows by 23 columns. The alternate arrangement, 23 rows by 73 columns, produces jumbled nonsense. The message forms the image shown on the right, or its inverse,3 when translated into graphics characters and spaces. The entire transmission lasted 1679 seconds and was not repeated.4

Dr. Frank Drake, then at Cornell University and creator of the famous Drake equation, wrote the message, with help from Carl Sagan, among others.1 The message consists of 7 parts that encode the following3:

  1. the numbers one (1) through ten (10)
  2. the atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA)
  3. the formulas for the sugars and bases in the nucleotides of DNA
  4. the number of nucleotides in DNA, and a graphic of the double helix structure of DNA
  5. a graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth
  6. a graphic of Earth's solar system
  7. a graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish

Because it will take 25,000 years for the message to reach its intended destination of stars (and an additional 25,000 years for any reply), the Arecibo message was more a demonstration of human technological achievement than a real attempt to enter into a conversation with extraterrestrials. In fact, the stars that the message was aimed at will no longer be there when it arrives.1 According to the Cornell News press release of Nov. 12, 1999, the real purpose of the message was not to make contact, but to demonstrate the capabilities of newly installed equipment.1

content

Contents

Explanation

Numbers

Part 1 — The numbers from 1 to 10
1 2 3 4 5 6 7 8  9  10
----------------------
0 0 0 1 1 1 1 00 00 00
0 1 1 0 0 1 1 00 00 10
1 0 1 0 1 0 1 01 11 01
X X X X X X X X  X  X <-least-significant-digit marker


The numbers from 1 to 10 appear in binary format (the bottom row marks the beginning of each number).

Even knowing binary, the encoding of the numbers may not be immediately obvious due to the way they have been written. To read the first seven digits, ignore the bottom row, and read them as three binary digits from top to bottom, with the top digit being the most significant.

The readings for 8, 9 and 10 are a little different, as they have been given an additional column next to the first (to the right in the image). This is probably intended to show that numbers too large to fit in a column can be written in several contiguous ones, where the contiguous columns do not have the base marker.

DNA elements

Part 2 — The elements constituting DNA
H C N O P
1 6 7 8 15
----------
0 0 0 1 1
0 1 1 0 1
0 1 1 0 1
1 0 1 0 1
X X X X X


The numbers 1, 6, 7, 8 and 15 appear. These are the atomic numbers of hydrogen (H), carbon (C), nitrogen (N), oxygen (O), and phosphorus (P), the components of DNA.

The numbers 8 and 15 are written in a logical extension of binary encoding, rather than with the contiguous-columns method shown in the message's number figures at the top:

Nucleotides

Part 3 — The nucleotides of DNA
Deoxyribose Adenine Thymine Deoxyribose
(C5OH7) (C5H4N5) (C5H5N2O2) (C5OH7)

Phosphate Phosphate
(PO4) (PO4)

Deoxyribose Cytosine Guanine Deoxyribose
(C5OH7) (C4H4N3O) (C5H4N5O) (C5OH7)

Phosphate Phosphate
(PO4) (PO4)


The nucleotides are described as sequences of the five atoms that appear on the preceding line. Each sequence represents the molecular formula of the nucleotide as incorporated into DNA (as opposed to the free form of the nucleotide).

For example, deoxyribose (C5OH7 in DNA, C5O4H10 when free), the nucleotide in the top left in the image, is read as:

11000
10000
11010
XXXXX
-----
75010

i.e. 7 atoms of hydrogen, 5 atoms of carbon, 0 atoms of nitrogen, 1 atom of oxygen, and 0 atoms of phosphorus.

Double helix

Part 4 — The DNA double helix structure
11
11
11
11
11
01
11
11
01
11
01
11
10
11
11
01
X

1111111111110111 1111101101011110 (binary)
= 4,294,441,822 (decimal)


DNA double helix (the vertical bar represents the number of nucleotides, but the value depicted is around 4.3 billion when in fact there are about 3.2 billion base pairs in the human genome).

Humanity

Part 5 — Human form, the height and population of humans
        X011011
         111111
X0111    110111
         111011
         111111
         110000

1110 (binary) = 14 (decimal)

000011 111111 110111 111011 111111 110110 (binary)
= 4,292,853,750 (decimal)


The element in the center represents a human. The element on the left (in the image) indicates the average height of a person: 1764 mm. This corresponds to the horizontally written binary 14 multiplied by the wavelength of the message (126 mm). The element on the right depicts the size of human population in 1974, around 4.3 billion. In this case, the number is oriented horizontally rather than vertically, with the least-significant-digit marker to the upper left in the image.

Planets

Part 6 — The Sun and the planets
               Earth
Sun Mercury Venus Mars Jupiter Saturn Uranus Neptune Pluto


The solar system, showing the Sun and the planets in the order of their position from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. (Pluto is now classified as a dwarf planet, but was still considered a planet at the time the message was written.)

The Earth is the third planet from the Sun - its graphic is shifted up to identify it as the planet from which the signal was sent. The human figure is shown "standing on" the Earth graphic.

In addition to showing position, the graphic provides a general, not-to-scale size reference of each planet and the Sun.

Telescope

Part 7 — The Arecibo radio telescope
bottom two rows:
     100101
<--- 111110X --->

100101 111110 (binary) = 2,430 (decimal)


The last part represents the Arecibo radio telescope with its diameter (2430 multiplied by the wavelength gives 306.18 m). In this case, the number is oriented horizontally, with the least-significant-digit marker to the lower right in the image.

Message as binary string3

0000001010101000000000000101000001010000000100100010001000100101100101010
1010101010100100100000000000000000000000000000000000001100000000000000000
0011010000000000000000000110100000000000000000010101000000000000000000111
1100000000000000000000000000000000110000111000110000110001000000000000011
0010000110100011000110000110101111101111101111101111100000000000000000000
0000001000000000000000001000000000000000000000000000010000000000000000011
1111000000000000011111000000000000000000000001100001100001110001100010000
0001000000000100001101000011000111001101011111011111011111011111000000000
0000000000000000010000001100000000010000000000011000000000000000100000110
0000000001111110000011000000111110000000000110000000000000100000000100000
0001000001000000110000000100000001100001100000010000000000110001000011000
0000000000001100110000000000000110001000011000000000110000110000001000000
0100000010000000010000010000000110000000010001000000001100000000100010000
0000010000000100000100000001000000010000000100000000000011000000000110000
0000110000000001000111010110000000000010000000100000000000000100000111110
0000000000010000101110100101101100000010011100100111111101110000111000001
1011100000000010100000111011001000000101000001111110010000001010000011000
0001000001101100000000000000000000000000000000000111000001000000000000001
1101010001010101010100111000000000101010100000000000000001010000000000000
0111110000000000000000111111111000000000000111000000011100000000011000000
0000011000000011010000000001011000001100110000000110011000010001010000010
1000100001000100100010010001000000001000101000100000000000010000100001000
0000000001000000000100000000000000100101000000000001111001111101001111000

or

00000010101010000000000
00101000001010000000100
10001000100010010110010
10101010101010100100100
00000000000000000000000
00000000000011000000000
00000000001101000000000
00000000001101000000000
00000000010101000000000
00000000011111000000000
00000000000000000000000
11000011100011000011000
10000000000000110010000
11010001100011000011010
11111011111011111011111
00000000000000000000000
00010000000000000000010
00000000000000000000000
00001000000000000000001
11111000000000000011111
00000000000000000000000
11000011000011100011000
10000000100000000010000
11010000110001110011010
11111011111011111011111
00000000000000000000000
00010000001100000000010
00000000001100000000000
00001000001100000000001
11111000001100000011111
00000000001100000000000
00100000000100000000100
00010000001100000001000
00001100001100000010000
00000011000100001100000
00000000001100110000000
00000011000100001100000
00001100001100000010000
00010000001000000001000
00100000001100000000100
01000000001100000000100
01000000000100000001000
00100000001000000010000
00010000000000001100000
00001100000000110000000
00100011101011000000000
00100000001000000000000
00100000111110000000000
00100001011101001011011
00000010011100100111111
10111000011100000110111
00000000010100000111011
00100000010100000111111
00100000010100000110000
00100000110110000000000
00000000000000000000000
00111000001000000000000
00111010100010101010101
00111000000000101010100
00000000000000101000000
00000000111110000000000
00000011111111100000000
00001110000000111000000
00011000000000001100000
00110100000000010110000
01100110000000110011000
01000101000001010001000
01000100100010010001000
00000100010100010000000
00000100001000010000000
00000100000000010000000
00000001001010000000000
01111001111101001111000

See also

References

  1. ^ a b c d e "Cornell News: It's the 25th anniversary of Earth's first (and only) attempt to phone E.T., FOR RELEASE: Nov. 12, 1999". Retrieved on 2008-03-29.
  2. ^ "Larry Klaes. Ithaca Times - Making Contact". Retrieved on 2007-07-27.
  3. ^ a b c d Cassiday, George. "The Arecibo Message". Retrieved on 2007-07-27.
  4. ^ Jay M. Pasachoff. "Chapter 20: Life in the Universe". Astronomy: From the Earth to the Universe, Updates by Chapter, 5th Ed.. Retrieved on 2007-05-05.

External links
© jGames.co.uk 2007 (some content from Wikipedia under GDL ) !-- ValueClick Media 468x60 and 728x90 Banner CODE for jgames.co.uk -->
Your Ad Here