Dutch amateur astronomer Eise Eisinga might have left school at 12 years old, but he built an inch-perfect model of the solar system in his living room.

here was a beat of silence as the room’s atmosphere shifted from inward reflection to jittery disbelief. “How is that even possible?” said one visitor, waving a pointed finger at the living-room ceiling. “Is it still accurate?” asked another. “Why have I never heard of this before?” came the outburst from her companion. Craning my neck, I too could hardly believe it.

On the timber roof above our heads was a scale model of the universe, painted in sparkling gold and shimmering royal blue. There was the Earth, a golden orb dangling by a near-invisible, hand-wound wire. Next to it, the sun, presented as a flaming star, glinting like a Christmas bauble. Then Mercury, Venus, Mars, and their moons in succession, hung from a series of elliptical curves sawn into the ceiling. All were gilded on one side to represent the sun’s illumination, while beyond, on the outer rim, were the most-outlying of the planets, Jupiter and Saturn. Lunar dials, used to derive the position of the zodiac, completed the equation.
The medieval science behind the Royal Eise Eisinga Planetarium is staggering, no matter how one views it.