Why does the globe tilt 23.5 degrees?

Astronomy calls the annual orbit of the sun on the celestial sphere "ecliptic", that is, the projection of the earth's orbital plane on the celestial sphere. The axis of the earth's rotation is inclined to the ecliptic plane by about 23.5 degrees (that is, the angle between the ecliptic and the equator is about 23.5 degrees), which causes changes in different seasons of the year.

A joke

Why does the ball watch tilt 23.5 degrees?

I don't study geography. Seeing the following joke, I want to know why the earth tilts 23.5 degrees.

earth

When the secretary visited a school and saw a globe in the classroom, he asked student A, "Tell me, why is this globe tilted 23.5 degrees?" 」

Student A was very scared and replied, "I didn't do it."

At this moment, another student B came into the classroom. When the secretary asked again, student B replied, "You know, I just came in and didn't know anything."

The director asked the teacher doubtfully what was going on.

The teacher said apologetically, "It's not their fault. The globe was already like this when it was bought. "

Seeing that the director's face was getting uglier and uglier, the headmaster hurried forward to explain, "What a shame," the headmaster said with a smile. "Because the school has limited funds, we bought cheap things."

I hope you can be satisfied with my answer!