If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

It can sometimes be difficult to comprehend huge scales of time and space. To understand scale, it can be helpful to see how familiar, everyday objects compare to objects at more extreme scales.  

This Scale on a String activity can help you to make sense of perspective across many dimensions by adjusting the scale to a smaller format. You can explore the massive distances of our Solar System using scale models made out of string. 

Comparison of size of the Sun and the Earth


First, you will need to calculate the distance of the Sun to other planets in our Solar System. If the distance from the Sun to the Earth is 2 feet in your scale model, you will need to calculate the missing distances using the table, below. If you like, use the Scale on a String worksheet. When complete, take a look at the Scale on a String answer key to compare your results.

A piece of string that is 100 feet long is ideal for the next part of this activity. You can use a shorter length, but you’ll need to recalculate the scale model distances. Stretch the length of the string out and knot in a ribbon at the intervals you calculated. 

Grab a friend, go outside, and each of you take an end of the knotted string. Walk away from each other until you’ve stretched out the entire string to get an idea of the kind of scale distances that separate the planets in our Solar System.