This lesson starts with Eon's dad genuinely impressed — because Eon asked a question most adults never think to ask. Watching his moon spin, Eon noticed it slows down and speeds up instead of turning at a steady pace. Why?
Keyframes, quickly
To make the moon spin, you set keyframes: "at the start, rotation = 0°," and "at the end, rotation = 360°." The computer then interpolates — it fills in all the in-between frames so the motion looks continuous.
The secret: it eases by default
Here's the answer to Eon's question. By default, the computer doesn't move at a constant speed between keyframes. It eases:
Slow at the start → speeds up in the middle → slows down at the end.
That "ease in, ease out" is what made Eon's spin feel uneven. It's actually how most natural motion works (a car doesn't go from 0 to full speed instantly), which is why animators often like it — but you can switch it to constant (linear) speed when you want a perfectly even spin.
Why this matters
The real hero of this lesson is Eon's question. Noticing "that's not even — why?" is exactly how scientists and engineers think: spot something surprising, and dig until you understand the cause.
Try it
Wave your hand from one side to the other. Did it start instantly at full speed, or ease in and out? (It eased — almost all real motion does. That's why "ease in/out" looks natural.)