(This post participates on the 117th edition of the Carnival de Mathematics, hosted by the blog Plus Magazine)

FIRST HALF

**Luis Suarez**is back! The player confirms his return to the

**Liverpool F.C.**at the end of the season.

It's been a frantic evening at the editorial office of the Liverpool Post, since Luis Suarez launched this

**publication**on twitter:**FeLiZ Año NueVO – haPPy NEW YeAr – BON aNY NOU !**

10 minutes after he has posted the tweet for

**wishing a happy new year**, the newspaper staff met urgently.
- As you can see, on the

**card**there are only 10 players, because Luis has crossed out his photo. This can only mean that**he wants to leave**his current team.
- Also, in the image we can see lots of

**red**devils, and the name given to the Liverpool FC team is: '**the reds**'. You must remember that he played for this club during the last 2 seasons, and he felt very happy there.
- On the other hand, we've got the encrypted notation he has written:

**1 – 515**. If the**Spanish League****ends**this year on 15/5, the message is clear: the F.C. Barcelona will have**1**player**less**on**May****15th**.
- That's true! And he has titled his image: 'Happy New Year', that is, he's very

**happy**because this coming year he will return back to his former club. We can also see a happy face in the number 1, which represents the player less at the end of the season, none other than himself.
- In addition, he has chosen a representation of the

**hell**for the background image. I guess that this year, with the disciplinary punishment and the adaptation to the new team, it has been something like a hell for him, and that's why he wants to return to Liverpool, where he was so well.
- We've tried it, but he's gone on holiday to a remote Pacific island with his friend Laudrup, and we can't get in touch with him, the same way as in the story Probability and sunrise.

- Anyway, and considering that the message is made in a

**mathematical language**, we should ask**Joe Vitruvius**if he thinks similarly as we do.
- O.K. Have you got his telephone number?

- Yes, now I'm going to ask him for coming here with us.

While Joe arrives to the editorial office, do you think that the interpretation of the message that the journalists of the Liverpool Post have thought is correct?

- Hello everybody. What happens?

- We've got a doubt with **twitter**.

**Luis Suarez**. Let's have a look at the picture he has published on
- He tells that on 15/5 the

**FC Barcelona**team will have one less player, who will go to the Liverpool F.C. to play with 'the reds', and he's very happy for this reason, because this season has been a**hell**for him.
- Hmm... Have you spoken with the player?

- We can't contact with him. That's why we want to ask you if you can find out something else in these

**numbers**, or if you confirm our analysis, before we publish the news
- Let's see, the message just says

**Happy New Year**in three languages: Spanish, English and Catalan. I can't see what's the problem.
- Yes, but look at the picture:

**1-515**. One less on 5/15, the day that the Spanish League ends.
- Well, it may mean something different.

- And what can you tell me about the

**red**demons? It's obvious that this is a clear reference to his**former club**, the Liverpool.
- Yes, they're all

**red**...
- And the photos of his teammates, among which he has

**crossed out**his face, this has no other possible explanation...
- I don't know. I think there's something hidden on this message. Let me think for a moment... As you told me, the background of the image is the hell. That's why devils are all around. But it's not just a simple

**hell**. It's a representation of the hell that**Dante**describes on his book**The Divine Comedy**.
- Dante was an Italian poet (1265-1321) whose masterpiece is the Divine Comedy, considered as one of the fundamental works of the

**universal literature**, in which we can study the transition from the Medieval to the Renaissance**world**.
- As for

**number one**, I can get no clue from it for the moment, or perhaps I should say I get too many clues: it represents the unity, is a happy, triangular and pentagonal number, appears 2 times in the Fibonacci sequence, is a Bell number, a Catalan number, a factorial and regular number, It's also the neutral or identity element of the product, and is the most common digit on a set of data according to the Benford's Law...**Too much data**. There's also a face inside it, but I don't know how to interpret it for now.
- And as regards the sign that separates number 1 from 515, I doubt if it's a

**minus sign**or if it's a simple**dash**between both numbers.
- In fact, at the time when Dante wrote the Divine Comedy, nobody used that

**symbol**for representing the**subtraction**, but the**letter M**(for the Latin word*minus*), to which later was added a line written over it to avoid confusions. It was in 1518 when Henricus Grammateus used it for the first time in solitary, eliminating the m, as the symbol of**subtraction**.
- On the other hand, we've got

**number 515**. You say that it refers to the expression**5/15**, that is, the 15th day of the 5th month, the day when the Spanish League ends. But I think there should be a separator between the 5 and the 15.
- I think we should focus on this number, the

**515**, because it can give us more**clues**about what he wants to tell with his**message**.
- As we said, the picture that is on the background of the tweet is a

**Botticelli**'s painting, inspired by ‘The Divine Comedy’ of Dante. As a good man from Renaissance, Dante, was a writer, but also a good fan of**mathematics**. Thus, in his work grants a great**symbolic value**to certain pairs of numbers, such as 3 and 9, 7 and 22, or 515 and 666.
- We find

**number 3**in many aspects of the book. It's a number that refers to the Holy Trinity, and that means balance and stability. This way, the poem is composed of tercets, articulated in**3 chapters: Hell, Purgatory and Paradise**.
- Meanwhile,

**number 9**is the number Dante assigns to**Beatrice**. 9 is the square of 3, and that way he enhances the beauty and importance of his beloved. In the work, this figure appears as the number of**divisions**or circles of the**Hell,**or the amount of different**heavens**of**Paradise**.
- The

**number 7**is a**sacred**number (seven liberal arts, seven colors of the rainbow, seven days of the week), which he uses to name the**divisions**of the**Purgatory**, while the**number 22**is a number closely related to the 7, since the result of the ratio**22/7**is very close to**number pi**.
- So with these 2 numbers that Dante refers to the

**circle**, the**most perfect figure**for the Pythagoreans. That way, he defines the heaven and the hell as 2 worlds formed by concentric circles.
- And finally we arrive to the most interesting numbers. Everybody knows

**number 666**is considered the**number of the Beast**or Devil in the**Apocalypse**. His antagonist or enemy must be the 'Veltro', or the one**sent by God**, who is marked by**number 515**according to the prediction Beatrice makes in the book: "Un cinquecento diece e cinque, messo di Dio..."
- If we write 515 en

**Roman numerals**we've got DXV, and if we change the order of the letters we get**DVX**, the Duke in command of the Holy Roman Empire, who will be chosen to fight the evil represented by the 666.
- Therefore, number 515 must be taken as if it was a positive force, opposed to the hell of the picture's background. This may mean that Luis is

**overcoming**the**bad times**of the past.- So

**everything**seems to be

**connected**, but we still haven't found what Luis Suarez wants to tell with his message.

- The one link I see between this number and the new year 2015, is that we can get this number by adding 15 hundreds to 515, but there's no longer relationship between them beyond the concentration of ones and fives in the operation.

- And if we study the

**properties**of the**number 515**, we get that it's a composite number, with 4 divisors (1, 5, 103 and 515), so it's not a prime number. It's neither a Fibonacci number, nor a Bell , Catalan or Lucas number. It's not perfect, nor abundant, nor polygonal. But it's deficient, undulated, odious, palindromic, square-free... and unhappy.
- As a curiosity, we've got that 515 is the

**addition of 9 consecutive prime numbers**(41 + 43 + 47 + 53 + 59 + 61 + 67 + 71 + 73), that the**Moon**'s orbital plane**is****inclined**at 5.15 degrees to the plane of Earth's orbit round the Sun,.and that if we multiply**number pi**by 0.515 we get approximately**the golden number 'phi'**(1,618), that you can see on my t-shirt, and that is so related to**Fibonacci sequence**.
- And if we analyze the

**number 2015**, the new year, we've got that it's a composite number, with 8 divisors: 1, 5, 13, 31, 65, 155, 403 and 2015. It's a deficient, evil, unhappy and square-free number, but it's not a Fibonacci number, nor Bell, nor Catalan, nor regular, nor perfect, nor polygonal number...
- It seems that we won't get any clue from these two numbers, either.

- On the other hand, if we focus on the face of one of the devils, we can see that it's

**Francis Bacon**, an amazing English**philosopher**, politician, lawyer and scientist (1561-1626).
- His work

**Novum Organum**was a starting point for modern science, with the development of the**empirical method**based on the observation and experimentation.
- Yes, we've already seen it. We find no relationship between the philosopher and Luis Suarez, but there's some connection with other

**Francis Bacon**(1909-1992), the**modern painter**of the 20th century, whose paintings are exhibited at the museum of Liverpool, and is so admired by Luis.
- Certainly, we think that it's a clear sign that he wants to return to this city to visit more often Bacon's collections. Also, there's a movie about the life of this author, titled: ‘

**Love is the devil**’. So it's obvious that he still loves his last club, the Liverpool FC.- What have in common the

**Liverpool**team and the devil?

- Well, the authentic team called 'red devils' is Manchester United. But Liverpool FC is also related to them. Just before playing a match against the Anderlecht team, the

**coach**Bill Shankly had the idea of dressing his players completely in red, to make them**look like devils**to**frighten more**their opponents. Thus they changed forever their uniform, and since then the club is known by the name of ‘**the reds**’.
- I understand. But the thing I can't comprehend is the meaning of the circles on the numbers: 2

**filled circles**on the fives, and an**empty**circle on the one...
- Or maybe yes. I think that this is the key to understand what's all this about: Francis Bacon, evil numbers, devils...

- Have you noticed the

**layout**of the players on the top of the card? There are five visible faces, one crossed out face, and another five visible faces, right?
- That's true.

- Just the same layout that he repeats with the figures of number

**515**and with the circles set over the numbers 5, 1 and 5. What if we draw 5 full circles, an empty circle, and 5 other full circles, and we compare them with the players' photos?
- What a strange coincidence!

- Well, I said before that Francis Bacon was an outstanding philosopher. But he was also the inventor of the

**binary encoding system**, not in its present notation, with ones and zeros, but with the letters A and B, known by the name of**Bacon's Cipher**, described in his book*The Advancement of Learning*.
- You surely know that the

**binary**system is a**system of numeration**in which numbers are written only using two types of figures: ones and zeros. We can say that all our today world, with the boom of the digital technology, consists nowadays of an infinite sequence of ones and zeros.
- And that's what Suarez has made in this message: a

**binary greetings card**. Let's transcribe the**number 2015**, which corresponds to the new year, to its expression in the**binary system**:**2015**

_{10}= 11111011111_{2}
- What do you think? Haven't you seen before this distribution of ones and zeros: a row of 5 ones, a zero, and another row of 5 ones again?

- That's right. With the photos of his teammates, and with number 515, Luis is trying to

**represent the new year****2015**.
- In addition, it's a very nice binary number, because it's a

**palindromic binary number**(you can read it the same forwards as backwards), the largest you can write with only 11 digits. The next one will have 12, and will be the 100000000001 (number 2049 in decimal system).
- All right. And does it mean the number one before the 515?

- For number one, as everybody who have read my story about the happy numbers knows, is a happy number. In fact, it's the happiest number, because all happy numbers converge at number 1.

- Therefore,

**1 – 515**means in**mathematical language****Happy 2015**!
- So, this is only

**a mathematical greetings card**for the**New Year**, isn't it?
- Exactly.

- Ok, but how can we be sure that he doesn't wants to

**go back to Liverpool**? Why else he would put so many**red**demons in the card?
- Yes, it's true, but we have given it no importance.

- Yes it has, a lot. Before I mentioned

**Bacon's Cipher**. With it, the philosopher replaced the characters with**sequences of 5 letters**, specifically**A**s and**B**s,**to encrypt**confidential documents. Later,**Leibniz**devised a detailed study on binary systems, using ones and zeros, thus establishing the foundations of the**current binary numbering system**.
- For example, if we want to

**encode**the word '**hello**' with the Bacon's Cipher, first we replace each letter by its code of 5 letters with As and Bs. Then we think on a**phrase**, with the**same length as the formed series**of As and Bs (it will have 5 times more characters than the original text). In our case, I've chosen the phrase of 25 characters (excluding the spaces) '**I like very much country music**'.
- Now we form

**groups of 5 letters**, which will match each one with the code A or B of the series. If the first letter of the series is an A, we will write the corresponding first letter of our invented text in capital letters, and if it's a B, then we write it in lowercase.
- We do the same with the remaining letters, in order, and finally we

**separate**again**the words**of the resulting text, to mislead our 'enemy':
- This way, we've converted the word '

**Hello**' into the sentence '**I Like VErY MUcH cOUnTrY MusiC**'.
- We've set that the uppercase letters correspond to an A, and lowercase letters to a B, but we could also use other methods to differentiate the characters, such as using different fonts of letters, or different colors...

- Now let's apply this

**steganographic method**of Bacon's Cipher to the sentence of Luis Suarez. For that, we separate the letters of the text in groups of five letter, and write an A at the position where there's a capital letter, and a B for lowercase. The exclamation sign will be considered as lowercase, because it's very tiny.
- What have we got?

**Love FCB**! I think you have lost your cover page...- Don't matter. We just have to

**change the headlines**:

- Many thanks for all, Joe!

- Thank you for thinking of me to solve the

**problem**. And I wish you all a**HAPPY 13*5*31**!
If you're interested in

**learning more**about the topics of this story, you can visit any of these wonderful articles: A symmetric number in Dante, Elgar's 515 cyphers, Shakespeare's secrets: a hidden cipher in literature's greatest works?, Bacon Cipher - Decoder, encoder, decrypt, encrypt, Binary system, Bacon's cipher encoder/decoder, How to make anything signify anything.
And don't forget to take a walk by the Carnival of Mathematics. There you'll find lots of excellent math posts that you'll surely like too.