Signal to show we are an intelligent race

Question

Background Information

Let's say that we are trying to catch the attention of other potentially intelligent species. This signal would be used to attract the attention of other intelligent species. If another species (of any possible number system, shape, technology...) were to intercept this signal, they could assume that it was from another intelligent species. For example, we could transmit:

11.0010010000111111011010101...

, which is pi in binary, both of which are concepts likely to have been developed in another species.

The Question

What would be a (semi-)universally understood signal to transmit to show to other species that we are intelligent?

Answer 1

Using the digits of a number isn't really the best way to express a number when communicating with an alien race as Extra Terrestrials would almost certainly use completely different methods for expressing number from us. In order to show our mathematical knowledge to aliens it would be better to find a method of communicating mathematics that doesn't involve any symbols. One way we could communicate our knowledge of math could be to send signal that looks like AA AAA AAAAA AAAAAAA AAAAAAAAAAA AAAAAAAAAAAAA AAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA as this would be a sequence of groups that all have the sequence of prime numbers as the number of individuals instead of using the symbols for the prime numbers so that they would not need to know what symbols we use for the prime numbers in order to recognize that it is a sequence of prime numbers. We could also send a signal like A AAAA AAAAAAAA AAAAAAAAA AAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA to represent perfect powers. Basically we would represent number in the most literal sense in terms of showing them by having numbers of things instead of the symbol for a number so that aliens could understand it even if they use different symbols for numbers. If we wanted to use pi we might send them a series of signals in which the length of each signal was close to pi times the length of the previous signal instead of using the digits of pi as they would likely have different symbols for 0 and 1 than the ones we use. If we wanted to teach aliens what symbols we use for different numbers we might send them the symbol next to clusters of objects that would have that number of objects and do it with many different types of objects so that they could see the pattern.

Answer 2

There is no need to try to convey any meaning to prove intelligence. Just the ability to send the signal proves a certain level of intelligence. The goal must be to make a signal that is likely to be picked up by the receiver, and interpreted as something other than a natural phenomenon.

Using several frequency and sending patterns we assume if structured enough to not replicate any natural phenomenon, and then cycling through the pattern on different frequency.

For instance first you do prime numbers on frequency 1, and even numbers on frequency 2, odd number on frequency 3, fibonacci on frequency 4. Then once you have done that for a while change it so that frequency 1 now does fibonacci, and frequency 2 does prime and so on.

Answer 3

A few years back, the SETI institute received what they thought was a signal from another intelligent species, it was a steady pulse of on/off at regular intervals, this turned out to be a neutron star (or quasar) that created the effect because it was spinning quickly. The principle, however, remains: the simplest signal you can send is something so regular in amplitude, frequency, and wavelength that it simply cannot be interpreted as background noise. However the signal is interpreted, it will always be shown to be extremely uniform; unlike most natural radiation. (excepting, of course, neutron stars)

Answer 4

The idea of using pi is a good idea, math after all is a constant in the universe. But you would have to incode it use some thing really basic. Morse code is the only thing that comes to mind, some one else could probably think of something better.

Answer 5

The signal would have to be really long. You cannot guarantee that the encoding we use would be understood by the target peoples too, so you would want to send a shipload of signals in the direction of target in order to give them enough information that they can start decoding it. It is a known rule that the quantity of encoded information is directly proportional to the probability of having it decoded.

Simply sending mathematical tables of 2 or 3 would be a good idea

2x1=2 2x2=4 2x3=6

The reason for this is that such information is relatively easier to decode than a single value such as pi or some other constant value.

Now you might question how would such basic information reveal our intelligence to the target species? The answer is that this information does not prove a much about our intelligence but the transmission of this information on radio waves means we have mastered e.m. communication, which is indeed a proof of tech development.

Answer 6

Prime numbers are a very good start. There is no known natural process that generates them. Once you have established primes as the context by transmitting the first few in some transparently simple coding scheme such as a number of pulses separated by silence, you can then repeat the same with gradually improved coding schemes, including checksums and redundancy and message start / end codes. And then you can transmit a large number that has only two prime factors M and N followed by M lines of N Bits.

If maths is a universal language it ought to be obvious to assemble the lines as "black" and "white" pixels in a 2D grid. We're now transmitting imagery. Whether we are perceived as intelligent or as moronic now depends on other factors far less definite than mathematical fact.

Answer 7

You can send out pulses using the numbers of the Fibonacci sequence as length, with every pulse separated from the next by an interval represented by the first 100 prime number, then repeating it from the beginning, with all the time in tenths of a second

So you have a transmission like:

F1 P1 F2 P2 F3 P3 ...

where Fn is the nth number of the fibonacci sequence and Pn is the nth prime number.

So you send a 1/10 pulse, wait 2/20, send a 1/10 pulse, wait 3/10, send a 2/10 pulse, wait 5/10, send a 3/10 pulse and so on.

The problem however is what frequency/encoding to use, since it's not obvious how an alien species communicate, but maybe the "magic" frequency of 1420 MHz (as used by Frank Drake) can be a good choice.