In front of the blackboard.
After listening to Xu Yun's speech.
Old Su slightly bent down, picked up a small pebble from beside him, and released it after picking it up.
A soft plop was heard.
The pebble naturally fell back to the ground.
"Gravity..."
Then Old Su repeated the word, with a thoughtful expression:
"The name is quite interesting, but Xiaowang, how should the 'heavy' in gravity be explained?"
Xu Yun thought for a moment and then said the answer he had prepared long ago:
"The 'heavy' in gravity refers to the weight of an object.
That is to say, any object with mass, no matter how small, will generate gravity along with it."
Old Su squinted his eyes slightly, simulating in his mind by replacing the stone with sand grains.
After accepting the concept, he continued to ask:
"So, Xiaowang, where does gravity come from?"
Upon hearing this question, Xu Yun's expression became slightly solemn, and he said:
