Suppose I were to tell you that you receive a 5µ Sv dose of radiation every time you get an X-ray at the dentist’s office, but a chest X-ray contains 20µ Sv. If you didn’t already know what a Sievert (Sv) is, would you be able to determine if either was deadly?

Chances are this is hard for you to do. That’s because you’re human.

It’s easy for us to visually compare 5 penguins to 10 penguins, or even 50 penguins. However, once you get to very large numbers, such as 50,000 penguins versus 100,000 penguins, that’s a lot harder. It’s the same with very small numbers, and it’s hard for us to fathom a billionth of a meter and compare it to 100 billionths of a meter. True, we can compare them mathematically, but it’s a lot more difficult to do the same just by looking at them.

That’s why it helps to use visual aids. Thanks to the Internet, there are plenty of them at your fingertips.

One of them that I find particularly fun is The Scale of the Universe. With the help of a sliding adjustment tool, you can visualize distances from the size of the entire Universe to the Planck length (10-35 m) and any other distance in between. By going back and forth along the scale, you will be able to get a better visual understanding of just how big or how small something is.

Another one that I like is xkcd, a webcomic that occasionally features charts using different tools and measurements of comparison. One of them looks at radioactive doses in different situations. If you take a look at the radiation dosage of a dental X-ray (5µ Sv), it - along with all the other dosages shown in blue put together - is significantly smaller than the radiation you would produce just by having potassium in your body (400µ Sv). You can continue to use the bits of data as tools to determine how big, or how small, each of these dosages are. Ultimately, all of the dosages will be smaller than a dosage someone would have received just by spending time by the Chernobyl reactor at the time of the 1986 disaster (50 Sv).

It is common knowledge that the Chernobyl disaster had catastrophic effects. However, what this chart does is show us in an easy-to-understand manner how small the doses of radiation we regularly receive are, as well as just how much we need to get sick.

I encourage you to look for more charts and visualization tools like these. They’re highly informative, they give you a sense of just how big or how small things can be, and they’re very fun!

Enjoy!