Using prompts like "It looks like those two stars are touching," I get the students to understand the
exaggeration in scale between the model star size and the distance between the stars on the model. Using
the "1 light year equals 5 centimeters" scale, the students perform a calculation about the size that Sirius,
the largest star on the model, should be. It works out to be roughly 1 × 10 cm or 10 nm—about the size of
a large molecule, such as an enzyme—so if the stars did not emit light, they would be invisible at this
scale.