It's World Book Day - April 23rd!

Hurray, time to remember a fun / interesting / touching / life changing book we once upon a time read!

If you are not a student, chances are that you are not reading books so often any more.

Most of us (myself included) have replaced a good book with an e-book, reading though a tablet or a smart phone.

World Book & Copyright Day

But hey, the World Book Day is here and it is nice to bring back some memories, while at the same time (hopefully) motivate someone to read a book of their preference..

World Book Day or World Book and Copyright Day (also known as International Day of the Book or World Book Days) is a yearly event on April 23rd, organized by the United Nations Educational, Scientific and Cultural Organization (UNESCO), to promote reading, publishing and copyright. In the United Kingdom, the day is recognized on the first Thursday in March. World Book Day was celebrated for the first time on 23 April 1995.
(source wikipedia)

On this day came to my mind a book I first read approximately 9 years back.

Ντενί Γκετζ - Το Θεώρημα του Παπαγάλου

Denis Guedj - The Parrot's Theorem

I used to hate math (I think I have mentioned it in the past too) but I just had to take & pass a course about Mathematics. It was then that I was trying to find a meaning;

Why Math? Why should people go through so difficult times and learn all that (useless stuff) ??

I was searching for books, movies and anything that could help me understand mathematics.

I really enjoyed reading this book, it explains many theorems in a very smart way and as it combines history, fiction and conversations - it creates a fun atmosphere and the reader learns in a fun way while a curiosity is triggered for further digging!

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Hippocrates and Proof By Contradiction

For you that might not know it, apart from the world known Hippocrates , often referred to as Father of Medicine there was another Hippocrates; the Hippocrates of Chios

As per references, he used to be a merchant but after having some unfortunate events in his life, he moved to Athens and became a great mathematician. The proof by contradiction (απαγωγή εις άτοπον) in latin reductio ad absurdum is traced to Hippocrates of Chios

Quoting from the book - The Parrot's Theorem (English - Ελληνικά)

"Σύμφωνα με αρκετούς, ο Ιπποκράτης είναι αυτός που ανακάλυψε την εις άτοπον απαγωγή. Η εις άτοπον απαγωγή ειναι ένα από τα ισχυρότερα όπλα της Λογικής. Μας δίνει τη δυνατότητα να βεβαιωθούμε για την αλήθεια μίας πρότασης αποδεικνύοντας ότι η αντίθετή της οδηγεί σε ένα παράδοξο, όπως για παράδειγμα "ένας αριθμός είναι ταυτόχρονα άρτιος και περιττός" [...] κλπ. " [...] "Αν θέλεις να αποδείξεις ότι μία πρόταση είναι αληθής, πάρε την αντίθετή της, θεώρησέ τη αληθή και μελέτησε τις συνέπειες. Αν είναι παράλογες, φταίει η υπόθεσή σου. Επειδή είναι λανθασμένη, οδηγεί σε παράλογες συνέπειες. Αφού λοιπόν είναι ψευδής, η αντίθετή της είναι αληθής. Αυτό ακριβώς ήθελες να αποδείξεις! [...]

"According to many, Hippocrates is the one who discovered the 'proof by contradiction'. Proof by Contradiction is one of the most powerful logical tools. It helps us to confirm the truth of a suggestion, by proving that its opposite leads to a paradox, like for instance "a number is at the same time even and uneven" [...] etc "
[...]
"If you wish to prove that a sentence is true, take its opposite, consider it true and see the consequences of your consideration. If they are illogical, it is because of your hypothesis. Because it is wrong, it leads to not logical consequences. So, it is false, its opposite is true. That is exactly what you were trying to prove! [...]
(my translation)"

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Thank you so much for dropping by and even more if you take the time to leave a comment!

(All images my own)
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