With the appearance of chess in Persia is connected one of the most beautiful and profound legends of the origin of chess. This legend I cannot omit here, the legend of how a humble sage proved to a powerful ruler that his power was limited and that the limits could be accommodated on a small chessboard.
Imagine the court of Shah Khusraw I Nushirwan (of the Sassanid dynasty). His magnificent palace, surrounded by a beautiful, extensive garden - more extensive than the famous gardens of Semiramide. On one of the cloisters, leaning against a stone balustrade, two young courtiers are conversing.
- The news of Eroes' disfavor had already reached me during the journey, says one of them. - What could cause the anger of our Shah... May Ormuzd give him a long life! After all, our mathematician and astrologer has been his favorite for many years?
- Ormuzd has justly punished this boaster, although he used a strange tool this time. Listen. A few days after you left, a wise man named Sissa Nassir came to our court. He showed us a beautiful new game that depicted a battle between two armies. On a wooden board, two hordes of infantry, battle chariots, steeds and elephants are facing each other. They are led by two chiefs. The battle continues until one of them is captured.
- What could be more beautiful than a real battle ?
- You say with a sneer... Wait until you know the game. And before that don't disrespect it, as it is very dear to our chess player, who now spends whole days at it.
I see. Surely the astrologer didn't show proper admiration?
You're wrong. He, too, was keen on chess (for that is the name of the game), and he showed enough sense not to win with chess. The reason for his disfavor is different. Behold, the chessman, made happy by a new amusement, promised Nassir the reward he would demand. This was at a solemn audience in the throne room. The whole court looked at the old sage with curiosity and envy, awaiting his words. I stood just behind the shah and wondered what I myself would have requested in his place? And he expressed a wish that astounded us all.
Marriage to the Shah's daughter ? Woman was created for our affliction, and Sissa Nassir is a sage. No!
He only asked for a certain number of grains of grain. As many as the chessboard itself determines if you put one grain on the first field, two on the second, four on the third, and so on, with twice as many on each subsequent field.
And you say that this Nassir is a wise man? What kind of a wise man is he who wants a handful of grain when he can get a bag of gold?
Our astrologer thought just like you. They all did. And Eroes had always looked at Nassir the wrong way. He was afraid he'd lose the Shah's favor. He had a good feeling... Hearing such a request, he took the opportunity to whisper to the Shah that Nassir probably wanted to insult him, such a powerful ruler, by expressing such a modest wish. I saw the shah wrinkle his brow angrily... But the old man persisted. He only asked Eroes how long it would take him to calculate the reward.
- You don't need an accountant for that! I would have calculated the grains myself, before the sand had even spilled in the hourglass.
This is how Eroes answered Nassir. But the latter, thanking the chessman, said that our mathematician himself did not know what he was talking about and that he was giving him two days to make the calculations. And do you know what happened? Eroes didn't make it... The whole court mocked him, the chess called him every day asking if he'd finished and offering to send him some market girls to help him... But we were all really amazed when our mathematician finally finished his calculations. Imagine that the granaries of all Persia would have to give all their supplies to Nassir for probably a thousand years...
Are you kidding?
No, I'm not. Do the math if you don't believe me!
Count it yourself, if you feel like it. But don't be too surprised at Eroes' failure. The decimal system was unknown at that time, for numbers greater than a million there were probably no appropriate signs...
To the curious and impatient I will say that the number of grains is:
18 446 744 073 709 551 615
This is calculated using the formula:
This quantity is hard to imagine. It corresponds to years of grain harvest from the whole earth!