# An unknown message from an unknown world

Overview:

On 10-29-2097 at 14:37, a prototype hyper-luminal communications device was turned on for the first time at Research Site 1039. To the marked suprise of the research team, one of the broadcast bands was in use. Someone is broadcasting a message on loop on broadcast band 20763. Every other band is silent.

The message is made of 6 series of tones. After each series, there is a 14.3 second pause; between repeats of the message, there is a 10.56 minute pause. In the below transcript, each tone is represented by a different number.

Given that the message is repeated with no other communications through the system, we assume the message is sent by the first group to invent the system and is intended to be received by someone else who invents the system.

At present, we don't know what the message means. Decoding it could be of extreme importance; that's where you come in. We need to know everything we can about the transmitting group, such as where they are and what they want.

We can say with 98.69% confidence that no other human civilization has invented this device, so the group responsible for the message must a non-human organization of some kind.

Message Transcript:

00 01 02 03 02 04 02 05 02 06 02 07 02 08 02 09
02 10 02 11 02 12 02 13 02 14 02 15 02 16 02 17
02 18 02 19 02 20 02 21 02 22 02 23 24 01 02 03
02 04 02 05 02 06 02 07 02 08 02 09 02 10 02 11
02 12 02 13 02 03 01 02 03 03 02 03 04 02 03 05
02 03 06 02 03 07 02 03 08 02 03 09 02 03 10 02
03 11 02 03 12 02 03 13 02 04 01 24 04 02 05 02
07 02 09 02 13 02 03 03 02 03 07 02 03 09 02 03
13 24 03 15 03 02 04 15 04 02 05 15 05 02 06 15
06 02 07 15 07 02 08 15 08 02 09 15 09 02 10 15
10 24 03 14 03 15 04 02 04 14 03 15 05 02 05 14
03 15 06 02 04 14 04 15 06 02 06 14 04 15 08 02
08 14 08 15 03 01 02 03 14 01 15 03 02 04 14 01
15 04 24 07 16 03 15 06 02 06 16 03 15 05 02 05
16 03 15 04 02 05 16 04 15 03 02 05 16 04 15 03
02 10 16 01 15 10 02 03 16 04 15 17 03 02 04 16
07 15 17 05 24 03 18 03 15 03 02 03 18 04 15 04
02 04 18 04 15 06 02 04 18 05 15 08 02 05 18 06
15 13 02 06 18 07 15 03 10 02 12 18 03 01 15 12
01 02 04 18 01 15 01 24 06 19 04 15 04 02 08 19
04 15 05 02 08 19 05 15 04 02 13 19 03 15 13 02
03 19 04 15 20 08 02 03 19 05 15 20 06 02 03 19
06 15 20 05 02 03 19 07 15 20 04 06 11 09 24 04
21 04 15 06 02 04 21 05 15 10 02 05 21 04 15 11
02 03 21 13 15 03 02 06 21 20 08 15 04 02 11 21
20 08 15 05 02 10 21 20 06 15 04 02 04 21 20 08
15 03 20 06 13 09 11 24 03 22 04 02 04 22 05 02
06 22 13 02 10 22 03 06 02 04 01 22 04 03 02 06
22 10 02 08 22 11 02 01 22 12 24 04 23 03 02 05
23 04 02 13 23 06 02 03 06 23 10 02 04 03 23 04
01 02 10 23 06 02 11 23 08 02 12 23 01

00 25 02 26 02 27 02 28 02 29 02 30 02 31 24 03
14 03 15 04 27 25 02 04 14 04 15 06 27 25 02 05
16 04 15 03 27 25 02 04 23 03 27 25 24 03 14 03
15 07 27 26 02 04 14 04 15 12 27 26 02 05 16 04
15 09 27 26 02 04 22 03 27 26 24 25 28 25 27 25
02 26 28 25 27 26 02 25 28 26 27 26 02 26 28 26
27 26 24 25 29 25 27 25 02 26 29 25 27 25 02 25
29 26 27 25 02 26 29 26 27 26 24 25 30 25 27 26
02 26 30 25 27 25 02 25 30 26 27 25 02 26 30 26
27 26 24 25 31 27 26 02 26 31 27 25 24 25 31 28
25 27 26 02 26 31 28 25 27 25 02 25 31 28 26 27
25 02 26 31 28 26 27 25 24 25 31 29 25 27 26 02
26 31 29 25 27 26 02 25 31 29 26 27 26 02 26 31
29 26 27 25 24 25 31 30 25 27 25 02 26 31 30 25
27 26 02 25 31 30 26 27 26 02 26 31 30 26 27 25

00 32 02 33 02 34 02 35 02 36 02 37 24 32 14 05
15 07 02 32 15 05 27 26 02 32 15 04 27 25 24 32
16 05 15 06 02 32 15 06 27 26 02 32 15 09 27 25
24 32 18 04 15 10 02 32 15 06 27 25 02 32 15 05
27 26 24 32 14 07 15 33 02 32 15 07 35 33 15 03
01 02 33 15 10 35 32 15 05 24 32 19 04 15 33 02
32 15 06 35 33 15 04 02 33 15 03 20 08 35 32 15
05 24 32 14 04 21 34 15 33 02 32 15 03 36 33 15
07 35 34 15 04 02 32 15 06 36 34 15 05 35 33 15
03 01 24 32 21 04 16 34 15 33 02 32 15 06 36 33
15 06 35 34 15 03 01 02 32 15 04 36 34 15 07 35
33 15 17 03 24 32 21 04 14 33 21 04 15 34 21 04
02 32 15 03 36 33 15 03 35 34 15 03 20 06 13 09
11 24 08 20 05 06 11 06 15 37 02 37 18 32 15 34
02 37 19 04 18 32 21 04 15 34

00 38 02 39 02 40 02 41 02 42 02 43 24 38 03 02
03 24 38 04 02 06 24 38 05 02 08 20 12 24 38 06
02 11 24 38 07 02 12 20 11 24 38 08 02 03 04 24
38 09 02 03 06 24 38 10 02 03 08 24 04 38 10 15
39 24 04 38 03 14 03 38 10 15 40 24 04 38 10 14
03 38 08 15 41 24 03 01 38 03 14 08 38 08 14 08
38 10 15 42 24 42 14 08 39 15 08 41 14 08 40 24
03 01 21 04 01 40 15 03 43 02 03 01 21 04 01 20
11 04 09 03 39 15 05 43

00 44 02 45 02 46 02 47 02 48 24 44 03 45 05 14
04 15 46 02 44 04 45 06 02 44 03 45 26 02 44 04
45 07 02 44 03 45 25 24 44 04 45 05 19 04 15 46
02 44 03 45 03 02 44 04 45 26 02 44 03 45 03 20
08 02 44 04 45 25 24 44 03 45 05 23 07 02 44 04
45 26 02 44 03 45 25 24 44 05 45 38 04 02 44 03
45 44 05 45 46 02 44 04 45 44 05 45 38 04 02 44
03 45 25 24 44 03 47 05 43 40 02 44 04 47 01 43
40 02 44 03 48 03 43 40 44 04 02 44 03 47 04 40
02 44 04 47 03 43 40 24 44 03 47 09 43 42 02 44
05 47 04 43 42 02 44 03 48 04 43 42 44 05 02 44
03 47 07 42 02 44 05 47 06 43 42

00 49 02 50 02 51 02 52 02 53 24 44 03 15 49 02
44 04 15 50 24 49 15 03 12 43 02 50 15 46 43 24
49 15 03 04 38 10 14 06 38 08 14 05 38 03 14 04
38 09 14 03 32 02 50 15 46 24 51 49 15 09 40 14
07 52 02 52 49 15 38 10 14 38 03 04 14 38 03 03
14 38 04 04 14 38 03 10 02 51 50 15 46 24 53 49
15 10 38 03 14 05 38 04 14 03 32 02 53 50 15 46
24 03 01 21 04 05 15 32 02 53 49 03 15 32 18 09
20 06 11 09 04 43 02 03 01 21 04 05 15 33 02 53
49 04 15 33 18 07 20 11 07 03 10 43 24 49 45 50
48 42 49 27 46 02 49 45 49 48 38 09 10 50 27 46


Partial answer: last two sections, and conclusion

For the first four sections, see Sconibulus's answer. For the rest I propose the following interpretations:

44 is "person" or "agent" or "party" or something like that. 45 is "says". 46 is "what?". 47 is "has". 48 is "gives". So the first section of series 5 has Alice asking Bob what 3+2 is; first Bob says 4 and Alice says no, then Bob says 5 and Alice says yes.

Then, in the last series,

49 and 50 are introduced as names for "person 1" and "person 2", presumably indicating Them and Us in that order. They weigh about 52kg; what do we weigh? Their bodily makeup is O,C,H,N,other in proportions roughly 14:4:3:2:1; what about us? The place they live is water and crust in ratio roughly 7:5, and the crust is O,Si,Al,Fe,Ca in unspecified proportions; what about where we live? Their star is H,He,other in ratios roughly 8:3:1; what about ours? Actually, they have a binary star system rather than a single star, masses about 2.4x10^30kg and 2.9x10^39kg. Those are about 1.2 and 0.15 times the mass of our sun.

At the end of the last series

perhaps they are proposing trade. They say: if you give us glucose, what is the result? And they say: if we give you uranium, what is the result? But this seems like a rather odd set of trades to propose...

Now,

aside from the whole binary-star thing, they and their dwelling-place seem rather similar to us. They have a slightly lower ratio of water to land than we do. They're a bit lighter than we are. And they have a binary star (or maybe they have expanded from one star system to another). But their bodies are of composition similar to ours; likewise their star (though its metallicity is greater than ours', which would tell me more if I knew anything about astronomy) and their planet.

If we are to work out where they live, it seems that

either we have to get it from the information we've been given about their stars (I've had a bit of a look through tables of information about nearby stars and haven't found anything that seems to match) or there's something significant about all those arbitrary-looking numbers at the start of the story. For aesthetic reasons, I hope there isn't.

the mass of the second star was meant to be 0.95 solar masses. That puts the binary system into very much the same ballpark as Alpha Centauri A&B, though unless I've miscalculated neither of the masses is quite right. But maybe either their astronomers or ours aren't very accurate? The list at http://www.johnstonsarchive.net/astro/nearstar.html shows no binary systems that match any better.

After consulting various sources (some recommended by OP, some found elsewhere) this seems like a pretty good match for

Kepler-1647 (AB) b, a planet somewhat larger than Jupiter orbiting nicely in the habitable zone of a pair of stars. (That is: it's a binary star system where the two stars are rather close, and the planet orbits them both.) The masses check out nicely. The metallicity doesn't seem quite right, but I may be misinterpreting the paper that announced the discovery of this planet. (The ways in which metallicities are reported are a bit peculiar.) My understanding from that paper is that the planet is thought to be a gas giant, which wouldn't be habitable by the likes of us nor have the sort of surface described in the message -- but perhaps it has a moon.

So, in conclusion, I think

the senders of the message probably live on a moon orbiting Kepler-1647 (AB) b; they might be somewhat like us biologically; they are interested in trading with us, selling uranium and buying glucose (!).

• Unless I've misread somehow it's A.8497*10^22 units in base 12, which is about 10.7*12^26 units in base 10, which is about 1.22*10^29 units. One unit is about 2.375kg so that's about 2.91*10^29kg. The mass of the sun is about 1.989*10^30kg. – Gareth McCaughan May 12 '17 at 10:03
• I'll be more blatant to bring this to a close: the system has a Wikipedia article, but Wikipedia doesn't know the mass of the second star; that I got from exoplanet.eu; it is on openexoplanetcatalogue.com as well (I just checked). – qwertyu63 May 17 '17 at 14:03

00 is

Start of Message

01 is

Zero

02 is

Number seperator, probably space or comma.

03-13 are

Digits 1-11, in a base 12 system.

14-23 are

Additional Symbols; 15 is equality, 14 is addition, 16 is subtraction, and 17 is negative, 18 is multiplication, 19 is division, 21 is exponentiation, 22 is <, 23 is >, 20 is the equivilent of a decimal point.

24 is

a Sequence Seperator, probably a newline?

Patterns are:

Enumeration of symbols, then Counting, then Primes, then Equalities, then Addition, Subtraction, Multiplication, Division, Exponentiation, Inequalities

25-31 seem to be

Logical Operators, 25 is True, 26 is False, 27 seems to be 'Evaluates To', 28 is AND, 29 is OR, 30 is XOR, 31 is NOT.

Patterns are:

Enumeration of symbols, True math, False math, AND, OR, XOR, NOT, NAND, NOR, XNOR

32-37 are

32-34, variables A,B,C 35 is an Implication (A+5=B, A=3 implies B=8), 36 is an Additional Assumption (A+C=B, A=3 and also C=2 implies B=5) 37 appears to be 2pi. The last set of messages in the section is 2piradius=circumference and piradius^2=area

38-43 are

38 is the Periodic Table clued by Atomic Mass, 39 is Diatomic Oxygen, 40 is Water, 41 is Carbon Dioxide, 42 is Glucose, my guess for 43 is a unit of mass? About 5.8Kg?

• Looks to me like it's more like 2.375 kg. – Gareth McCaughan May 8 '17 at 21:16
• Ah, I think there may be an error. It says 10^20 (water) = one unit, and 10^20.9271 (oxygen) = 6 units -- all numbers base-12, of course -- and that's correct only if we take oxygen to mean O rather than O2 in the second. Or have I goofed? – Gareth McCaughan May 8 '17 at 22:10
• It's supposed to be ~2.37 kg. Oxygen is my mistake. I meant O2, but my math used O. I'll have to fix that. – qwertyu63 May 12 '17 at 2:13