How big is that bread box?

What comes to mind when you hear someone describe something as "bigger than a bread box"? Firstly, I suppose you have to know what a bread box is, which most homes probably don't store their bread in these devices from the 1950's anymore. Forgetting the box though, most us can image how big a loaf of bread is. So anytime we attempt to describe the size of objects using other objects as references, such as the bread here, we make an assumption that 1) everyone knows the size of a typical loaf of bread and 2) that size doesn't change very much from person to person. This technique may work great for explaining most of the day to day objects we can visibly see, but what about really, really small objects or really, really big objects? What is our reference object?

The reality is, we don't have reference objects for really small objects like red blood cells, viruses and atoms. We can't see those objects with our naked eyes so it's difficult to image just how small they truly are. The same is true for incredibly large objects like planets, stars and even other galaxies. So how can we come to a point where these usually "invisible" objects become visible? We need a SCALE...

A scale or magnitude of size allows us to discuss very small and very large objects using units of measurement that we use for measuring objects that we can see with our own eyes. For example, an average sheet of paper is about 0.1 mm thick. If you lined up 1 million (1,000,000) atoms in straight line, that would roughly equal the thickness of that piece of paper. The ability to make comparisons like this help us image just how big or small everything around us is.

Check out this site (click "PLAY" after it loads) for an amazing comparison of objects from the extremely small to the impressively large.