This is a cool tool for comprehending, appreciating, and demonstrating the scale of our universe. We’ve all seen the classic film, Powers of Ten (I hope), as the best way to get a sense of our cosmos. It’s still effective, but two bothers have made an on-line portal that blows Powers of Ten away.
Check out The Scale of the Universe 2. It takes a minute to load. Once ready, be prepared to have your horizons stretched. I like the way they pile in the expected and unexpected size examples, which anchor the scale in a refreshing way. The continuous zoom is what makes this device work, rather than the quantum powers of ten of the film. (In fact you can read off the powers of ten in this model as well.)
BTW, this app is what electronic "publishing" is really about.