In order to make a scale model of the galaxy in which stars are represented by salt grains,how far apart would neighboring salt grains be?

Question

Quizplus · Accepted Answer

The distance between neighboring stars in our galaxy is about 5 light-years, which is approximately 30 trillion miles. If stars are represented by salt grains, then the scale would be 1 grain = 30 trillion miles. To make a model that is practical in size, we can use a smaller scale, say 1 inch = 1000 light-years. This means that 1 inch in the model represents 1000 times 30 trillion miles, or 30 million trillion miles. If we use fine grain salt, with an average diameter of 0.2 mm, then the distance between neighboring salt grains in the model would be 1 inch divided by 30 million trillion miles, or about 10 miles. Therefore, the best choice is B) 10 miles.

In Order to Make a Scale Model of the Galaxy