If you Google the solar system, you will be shown images of all the planets in our solar system laid out in the order they rotate around the sun. The problem with these images is that each planet's respective distance to the sun is not shown to true scale. This leaves the viewer without a true understanding of just how far away each planet is from another. That’s why Alex Gorosh and Wylie Overstreet set out to make a true-to-scale representation of the solar system.
In order to get a scale representation, they used a small marble to represent Earth. With Earth the size of a marble, they then needed seven miles of open land to show the solar system. Once everything was in position, they showed just how true to scale everything is. By standing near the model earth and also standing on the real earth, you would now have the exact same perspective for both the model and real life. Because of this, the model sun and the real sun appear to be the same size.
Here is another video that shows more detail of how they put everything together.