A battle of wits
A learned foreign scientist said he wanted to challenge the wits of the most knowledgeable person in the city.
The townsfolk called for Mulla Nasrudin.
When Mulla Nasrudin arrived, the foreigner drew a circle in the sand with a stick.
Nasrudin frowned, took the stick, and divided the circle in two.
The foreigner then drew another line through the circle that divided it into four equal parts.
Nasrudin pretended to gather three parts toward himself and to push the remaining part toward the foreigner.
The foreigner then raised his arm above his head, and wiggling his extended fingers, he slowly lowered his hand to the ground.
Nasrudin did exactly the same thing but in the opposite direction – he moved his hand from the ground to a height above his head.
And, that completed the foreigner's tests, who bowed his head in deference before Mulla Nasrudin who smiled cannily at having won the academic duel and then walked away.
Later the renowned foreign scientist explained his game of wits privately to the city council..."Your Mulla Nasruddin is a very clever man," he began, "I showed him that the world is round – and your Mulla Nasrudin confirmed it but indicated that 'it also has an equator'.
Then when I divided the world into 4 parts, he indicated that it is '3 parts water and 1 part land', which I can't deny.
Finally, I asked him ‘what is the origin of rain’ and Nasrudin answered quite rightly that 'water rises as steam to the sky, makes cloud, and later returns to earth as rain.'"
When they got him alone, the ordinary townsfolk asked Mulla Nasrudin what the challenge was all about?
Nasrudin said, "Well, that other fellow first asked me, 'suppose we have this round tray of halwa’?
So, I said, 'You can't eat it all by yourself, you know. So, I'll take half.'
Then that haughty foreigner chap got a little rude, saying, 'What will you do if I cut the halwa into 4 parts?'
That upset me, so I said, 'In that case, I'll take three of the parts and only leave you one!'
That softened the impertinent foreigner scientist a bit, I think, because then, with the motion of his hand, he said, 'Well, I suppose I could add some walnuts and pistachio nuts on top of the halwa.’
I cooled down too and said, 'That's fine with me, but you'll need to cook it under full flame, because an ash fire just won't be hot enough'.
When I said that, the scientist knew I was right, so he gave up the game, and conceded defeat..."