A message has come from another galaxy. The radio receiver detects 7 different wave forms and translates those into letters; now your task is pretty easy.

Decipher the message, and determine how many fingers the aliens have on one hand.


Do you think the alien's idea was good? Any answers need to be accompanied with an explanation.


Perfectly equivalent message if aliens have 2 finger less


  • $\begingroup$ Yes it was better just asking for how many fingers in one hand. I already edited thanks, feel free to improve that further. The point is that number of hands and feet does not matter at all. $\endgroup$ Commented Sep 7, 2016 at 16:52
  • 1
    $\begingroup$ Gotcha. Good stuff. $\endgroup$
    – John
    Commented Sep 7, 2016 at 16:53
  • $\begingroup$ How do you know the message is related to fingers? $\endgroup$
    – newzad
    Commented Sep 7, 2016 at 17:06
  • 4
    $\begingroup$ Because I know the alien who wrote it. $\endgroup$ Commented Sep 7, 2016 at 17:07
  • $\begingroup$ How many fingers does your alien friend have on one hand? $\endgroup$
    – Avigrail
    Commented Sep 16, 2016 at 7:53

3 Answers 3


I initially thought the aliens have

7 fingers per hand-like-thing

Because the code sent has

7 values

and beyond that

translating C->0, V->1, F->2... the second half of the message, using the 0 value as a separator, is 1,2,3,5,11(8 base 7) The Fibonacci sequence.

However, Given the hint

It's possible the C is a null value, and the 0 digit was attached to the other end of the stream.

That gives us a sequence of

1,2,3,5,7 which is almost Primes, but starts with 1.
or 1,2,3,5,11 base 6, 1,2,3,11,13 base 4.

Which would mean that the Aliens have

Either 3, or 6 fingers per hand.

  • $\begingroup$ Almost correct, with one problem. You had one oversight about the meaning of values, which yielded to a uncorrect sequence.. I can add a hint later :) you could as well just interpreted the sequence as 01020305011000 according to your interpretation $\endgroup$ Commented Sep 7, 2016 at 16:47
  • 1
    $\begingroup$ @DarioOO I was kinda assuming it was a SETI like message, "These are our digits. Look they're digits, check out this simple math. The 0 then represents not only 0, but the Base State/Carrier Wave, I treated it as a seperator because the sequence didn't call for it. $\endgroup$
    – Sconibulus
    Commented Sep 7, 2016 at 16:52
  • 1
    $\begingroup$ Yes your idea is right, I'm not sure how SETI exactly work, but I hope they don't use a symbol both as separator and as a digit ;) otherwise aliens could have been already laughing at us XD $\endgroup$ Commented Sep 7, 2016 at 16:55
  • $\begingroup$ A number of messages sent to space (e.g. Arecibo Message and Cosmic Call) used binary to transmit black & white images, and interesting things like digits only appear once the image is assembled. I would recommend reading through the second link when you get a chance, interesting stuff. (Also sort of a bonus puzzle!) $\endgroup$
    – Phlarx
    Commented Sep 7, 2016 at 18:29
  • 1
    $\begingroup$ If this solution is correct, does that mean humans have 10 fingers on each hand? (Or am I missing something? [And, no, I don't mean "am I missing 5 fingers on each hand"!]) $\endgroup$
    – YowE3K
    Commented Sep 8, 2016 at 2:11

After reading the Sconibulus very interesting answer, (he is the real solver) the two sequence are

000 / 112233445566 / 01020305011 /000 (X fingers per hand)


000 / 11223344 / 010203011013 /000 (X-2 fingers per hand)

And this is my possible and alternative interpretation

Aliens are not transmitting the Fibonacci sequence, nor the PI, nor the EUler/Neper number etc. First and last part of the sequence are like CQ morse code: my call starts with CQ CQ CQ wich means "Hey I'm calling here, there is some one who is listening? Be ready for my transmission!" or "End of the message, I will not transmit anymore, now take a cofee ".

Second part

112233445566 seems to be like "Check out how many different digits we have! 6 different state!" (4 in the alternative situation). As Sconibulus pointed out, 0 is the Carrier Wave. So the signals started with to impulses (1 sec of transmission, 1 sec off, 1 sec on, 1 sec off, 1 sec on and then the values as peaks in the wave)

Third part

01020305011 becomes 1 2 3 5 11 wich in base 6 is 1 2 3 5 7 / 010203011013 becomes 1 2 3 11 13 wich in base 4 is 1 2 3 5 7. They are the first prime numbers (except for 1) in sequence.

Conclusion: How many finger?

Assuming that humans use base 10 because have 10 fingers, assuming that clever and advanced aliens could not exist without fingers, the should have 6 (or 4) fingers. On both hands? Could be, since both are even numbers. But what about number 1 (wich is not a "real" prime number). Assuming that aliens have the same rigid behaviour of our math teachers in terms of definitions, we could read the sequence as "Look at my beautiful numerical system based on 1 hand: I am telling you that the first prime numbers are 2 3 5 7..." And, after all, who can assure us that aliens have exactly 2 hands?

One more note

My solution is wrong if you note that nor in the first neither in the second aliens use their last digit. But it could be transmitted (as a composite value) in terms of amplitude of the wave to say "I am transmitting between ZERO (C) and MAX state T (or G)" instead of "I have 1,2,3,4,5,6 fingers. 6 different states in my numerical system but I will never use the last because if I would have 10 fingers my bigger state were nine!"

Sorry for some bad english! Thank you for the question

  • 1
    $\begingroup$ Yes, Aliens should have showed a sequence long enough to use the "0" digit (since the base is even the digit can only appear in intermediate positions). Or better even started with a sequence that shows numbers just increasing. Puzzling.SE is increadibly useful for testing SETI like messages. :). The 1 was included in the sequence of primes because without it it could be ambiguos if the first digit was 1 or 0 instead. $\endgroup$ Commented Sep 13, 2016 at 8:40
  • $\begingroup$ You got a important point which is identifying that the first part of the message is a "HandShake". "Ehi I'm going to use these symbols. As long as I'm able to award the Bounty I will award both answers +50 (+50 to one, and then start another Bounty) $\endgroup$ Commented Sep 13, 2016 at 8:46
  • $\begingroup$ The system do not allow to award 50, so you will get 100 - enojy XD $\endgroup$ Commented Sep 13, 2016 at 14:52
  • 1
    $\begingroup$ @DarioOO thank you for this reward and for let me imagine to work in the SETI program with real aliens! XD $\endgroup$
    – marcoresk
    Commented Sep 13, 2016 at 17:59
  • $\begingroup$ No problem :) planning to add more SETI like questions in future :) $\endgroup$ Commented Sep 14, 2016 at 8:48

(I found answer in JavaScript)

My answer is:

6, 3 fingers for hand.



Output: 29


I delete the duplicate letters: "CVFBGHT".


I create a variable.
var a = "CVFBGHT".length;


I subtract the length of whole message with the message without duplicate letters.
var b = msg / a;
Output: 4.142857142857143


b becomes a string, and I count the length of string.
Output: 17


"hands" word has 5 letters,
var word = 17 - 5;
Output: 12


word/2 = 6.


The aliens have 3 fingers in each hand.

  • $\begingroup$ Why -1? Let me know why $\endgroup$
    – 1415
    Commented Sep 13, 2016 at 17:31
  • 1
    $\begingroup$ umm... 29/7 isn't evenly divisible, any finite string you get out of that is an artifact of your interpreter. You also don't explain WHY you're doing any of the things you're doing. $\endgroup$
    – Sconibulus
    Commented Sep 13, 2016 at 17:31
  • 2
    $\begingroup$ On the other hand, welcome to Puzzling! Thank you for showing your work, and for your use of spoiler tags. $\endgroup$
    – Sconibulus
    Commented Sep 13, 2016 at 17:34
  • $\begingroup$ Arbitrary Manning of numbers can yield any result you want. Simplest explaination is Always prefferred. DIdn't downvoted $\endgroup$ Commented Sep 13, 2016 at 17:36
  • $\begingroup$ @Sconibulus 29/7 is disivible, It returns 4.142857142857143. I convert 4.142857142857143 in string. $\endgroup$
    – 1415
    Commented Sep 13, 2016 at 17:40

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