Assignment 6
CETI
Due: March 15, 2012


The Search for Extraterrestrial Intelligence (SETI) is a passive attempt to search for extraterrestrials. It involves only listening. SETI has as its nonpassive counterpart Communication with Extraterrestrial Intelligence (CETI). The issue for SETI is simply knowing whether or not extraterrestrials have communicated with us. Later, we determine what the extraterrestrials are saying. For CETI, the key is to devise a message which can be beamed into space and which an extraterrestrial would have a fighting chance of understanding. This task is not so simple. Below is a trial message made by Frank Drake (using a method he believed to be promising) which could be sent to an extraterrestrial civilization.

1. Coming up with an understandable message is difficult. Consider the following message constructed by Frank Drake which he envisioned could be beamed into space. The signal was composed of a string of 551 bits (pieces) of information, each bit either a "zero" or a "one." The sequence of 0s and 1s is shown below. The message is actually a single string of 551 numbers and it is only for convenience that it is broken into rows (whch run left to right).

Imagine you are an extraterrestrial who received this string of 0s and 1s and determined firstly, that the message was sent from the Earth, the third planet from the star in our little Solar System, and that the message was from an intelligent civilization. Your next goal is to transform the radio transmission's sequence of 0s and 1s into a message (make a picture) which you can interpret. Your first task is to figure out how to divide the sequence of 1s and 0s into a two-dimensional grid (using the graph paper below). How should you divide up the string of 551 numbers? What is a sensible number of rows and colums you should have in your grid? Is there a best way? How did you finally choose to divide up the string of bits?

2. After you decide how to divide the string of bits, transfer the numbers to the grid (graph paper below) to form a picture. For the squares which contain ones, blacken the box. For the squares which contain zeroes, leave the box white.

2. What do you make of the message? What information can you discern in the message?

3. Was this a sensible attempt? If you were asked to improve this attempt to communicate, what would you suggest?