I don't know really why but one night before trying to sleep it came to my mind, how it could be possible to communicate with aliens. Since I don't really know anything about this stuff this could be mostly regarded as fiction. But since I spend some time thinking, I want to publish it nevertheless ;)
Before I start - some assumptions about the other species and data transmission:
- Communication can't be done in realtime - so there is no question-response possible (maybe with 10 years difference)
- The transmitted Signals are 0, 1 and a break (no communication) which I would write as _ I think this is the most basic a Signal could get - first I don't know what technologies are possible. Second I don't know if an alien race would understand something more complex (I mean binary is easier than something with 1024 states)
- The transmission is lossless (could be achieved by resending everything -> redundancy)
- the aliens are at minimum as advanced as we were 30 years ago.. So maybe they only could monitor the space but not send and maybe they don't even have machine assisted computation or just very basic computation
- they have many people who can decrypt our messages and brainstorm about it
- they are interested in communication
How to communicate?
The question could also be written as "What can be understood?".
language/words -> probably not - (I think) it is not possible to get a translation without having any connection - we have a different culture/history/environment
math/numbers -> probably - we could send the numbers from 0-100 as something like: 001_010_011_100 ... This sequence could be made to show them that we are intelligent enough for counting :) - so a first hello I'm not sure how to display fractions in binary, so that they are understood without explanation. So I think it is easier to just send them our decimal, and then send them a special code for a decimal separator. Like this: 0=0000,1=0001,2=0010,3=0011,4=0100,5=0101,6=0110,7=0111,8=100,9=1001 - and a special sign the ","=00001 all separated by _ My first introduction would be the basic counting from 0-100 this time in decimal - I think they could grasp it. Then I would send them 3.14159 and some other universal constants.. This would show them what the ","(00001) means. With that we also could show them other stuff and introduce more signs: 00010="+" and send them 5+3=8 and some other equations for a learning effect. With the above we could try to teach them shapes.. I think we could just encode our letters in binary and say: "Circle: 3.14159" or "Square: a²+b²" And so on.. But with this I fear a bit that they might have a problem with one word/symbol and then wouldn't understand most of the messages which build upon them... So my next idea raise:
pictures -> this was one of my last thoughts because I had it as something in mind where I would think this is to hard to understand.. But there exists a really intuitive encoding. Just take 0 as black, 1 as white and _ as newline and you can craft basic pictures.. Like this:
000000000000000000 000011000000011000 000011000000011000 000000000000000000 (if you don't see: a Smiley) 000010000000010000 000001111111100000
I would send them following: 3.14159 and then a picture of a circle. Then a picture of a smiley and maybe some stick figure comics :) This would make them see we are very funny and so it don't get boring for them to decode.. To send them better quality images it should be possible to use the numbers between 0 and 1 for lightning (so 0.5 means grey and 0.9 light-grey) or we should send them large pictures with thousands of bits per line.. Disadvantage of this method: what if they are very large ants and communicate with touching/sniffing? What if they don't see in 2D (is this possible)? Also the data required for sending would be very high without any encoding (But I think: Run-length-encoding should be not too hard to teach)
What should we send?
Since we don't know anything about them, I think it probably would be best to send them some science.. Either they will learn, or they will find mistakes or they already know, but see that we try to help other species. Also one often gets what one is giving -> so they might send us their science too.. Besides that I think it would be great to send our DNA to them. Additionally it would be great to give them cultural insight - like sending them movies of us, nature and so on. And in the end, when communication gets cheap.. I would dump the whole internet on them so they get the full picture and will read my blog post and will praise me as the inventor of alien-communication :).
I think it is possible to communicate with someone even if only 0 and 1 could be sent. Pictures and math might be best understood. Science, DNA and entertainment should be sent.