Lots of signals have gone into space such as TV, radar and radio. The signals have been betraying our presence for 60 years and have passed over about 6000 star systems and are reaching new systems every day.
This would seem to be enough, even though we haven’t received anything back yet, but what if our messages are unintelligible or lost in the background noise of other planets? Language and culture is another problem as ET probably does not have the Oxford English dictionary or a maths book to hand.
Help could be at hand though from a language called lincos which was first described in 1960 by Dr Hans Freudenthal in one of his books called “lincos: design of a language for cosmic intercourse, part one”. In 1999 Yvan Dutil from Canada created a message from Lincos that he thinks may be able to be decoded and read by aliens with no knowledge of humans.
Dutil is an anti-cryptographer as opposed to a cryptographer and therefore tries to make information as easy to read as possible. The four hour message was transmitted into space by a Russian radio telescope in 1999. The radio signal shifts back and forth between two frequencies which are 48 kHz apart. It is a form of binary with one frequency representing on and the other off. Put together, just like a computer does, the ons and offs can form any language that is required.
The message’s journey will encounter distortion by static which will make it hard to read at the other end. Redundancy is the solution. Redundancy is a way to make the message readable even if information is lost. T-e ca- jum–d is readable with a little thought and comparison of other words in the message. We compare the words to the words that we already know but the aliens would compare it to other words in the message.
Patterns are also a part of the redundancy in the message one pattern being a box around each page. If one page’s box is distorted comparison with other page’s boxes will show how to correct the distorted page. This will allow the message inside the box to be read.
Even more redundancy is included in the actual message. Each symbol is a picture which is seven bits high and five bits wide representing a single concept such as numbers, objects or ideas such as pressure (one bit = one frequency, the other bit = the other frequency). Each one of these symbols differs from the others by at least seven bits which is enough to correct any error of three bits. This means that if a 10th of the message was lost it would be possible to reconstruct the whole message.
The actual message is full of patterns at regular intervals which it is hoped they would pick up. For this some sort of sight is necessary and it is assumed that they would have this sight if they had received the signal through a radio telescope.
To learn our language they need to be taught the various symbols. This is done within the body of the message by making the beginning of a message very predictable. This is where lincos comes in which is a jumble of mathematical symbols. All our assumptions about maths and language are put to one side and lincos build them up from scratch. Every symbol is defined by symbols that come before and this means that the first symbols must be concepts that have no definition.
Maths is the best language to send as nations on earth in the early days learnt how to count but weren’t communicating with each other. This would imply that aliens would be able to read the mathematical message. The first line of the message that Dutil sent contains numbers from zero upwards. Each number is transmitted in three different ways as dots, as a binary number and larstly as a strange looking numeral.
The second page lists prime numbers and the third teaches them how to add up. Edition is followed by subtraction, multiplication, division and exponentiation. The section ends with good old Pi which can be found in a lot of places in mathematics and the Pythagorean theory (remember triangles!). These are some of the oldest mathematical objects that were made by human beings.
Then the message moves on to chemistry and physics including time and distance, mass and charge and temperature amongst others. From these basic concepts sounds, solar systems the Earth and humans are described. DNA and the radio telescope’s properties come close to the end with the message finally finishing with a request from the aliens for the same information back, let us hope they are not freeloaders!
Nothing has been heard yet (unless it was filtered into the spam box) and we are still waiting. If this message worked we should receive a message at any time but let’s hope we recognise the message back.