Paas, a retired architect, was inspired by a Midland fourth grader’s drawing of the sun and planets. In 2013, he was volunteering at his grandsons’ school there when the student showed him his drawing. The student had recognized the variations in the size of the planets but had drawn them close together and in a straight line from the sun. Paas saw a teachable moment.
“I suggested that he might draw them on a very long piece of paper such as a roll from an adding machine (of course he had no clue as to what an “Adding Machine” might be),” Paas emails. “I suggested that he could draw them to scale with the distances between them at the same scale.”
But when he did the math, Paas “soon realized that I was the one who was clueless. If we drew the smallest planet as of an inch in diameter, there was no roll of paper long enough nor any school big enough to allow the distance from the Sun to Neptune to be shown. At a scale of 1 inch equal to 50,000 miles, Mercury is 1/16” diameter and the distance from the Sun to Neptune is 7/8 of a mile.
Feeling “reasonably certain that I was not alone in having failed to be aware of this,” he looked for a way to illustrate his insight.
He first suggested creating to-scale displays of the Sun and planets and the distances between them on posts on the school grounds. The staff was enthusiastic, but central administration nixed it over concerns about mowing around the posts.
So Paas offered an alternative: a series of paving bricks engraved with each respective planet’s name and distance. He then made planet models with descriptions displayed inside a wood box on a tripod stand that the students could carry as the group walked from brick to brick.
“The scheme was acceptable to everyone,” he emails, “and the only conflict we had was over who got to carry the box.”
After his grandsons finished elementary school in Midland, Paas refocused his volunteer efforts at Bach, because it’s close to his and his wife’s Ann Arbor home. In the fall of 2019, he proposed a to-scale solar system that would be centered on the school playground and extend out into its west-side neighborhood.
With permission from the school and neighbors located at the appropriate distances, he went to work constructing displays that included appropriately sized images of each planet.
The Sun, Mercury, Venus, Earth and its moon, and Mars fit on the Bach playground. A key there directs explorers to more-distant planets. At a scale of one inch to 50,000 miles, a little less than a one-mile loop from the northwest corner of the playground spans 2.8 billion miles of space.
Each display includes details about the planet’s geography, the ancient mythology behind its name, questions (“Why is Jupiter’s red spot shrinking?”), and information (“Voyager 2, a U.S. satellite, was launched in 1977 and flew past Neptune in 1989.”)
Paas says that the idea of scale comes naturally to an architect, but it’s “something that kids may not have thought about. We always do a classroom presentation prior to going out and doing the tour. We talk about other things that kids experience at scale, like dolls and dollhouses, model trains and cars, and stuffed animals.”
Paas isn’t done with scale-model solar systems. Next, he wants to work with volunteers to create a “more sophisticated version in a place that was more likely to be used by the general public.”
He’s got his eye on a stretch of the Border-to-Border Trail at Gallup Park.