Big Numbers

Think about all the grains of sand in all the deserts and beaches on the planet. That’s a ridiculously big number—seven and a half quintillion (7.5 x 10¹⁸), at least according to one estimate.

As many grains of sand as there are, there are far more stars out there in the observable universe. This kind of weird comparison can be useful when you need to understand something like deep time, where the numbers that measure our daily experiences don’t amount to a hill of beans.

It’s useful to us because we can get an idea of how many grains of sand there are in the world. Well, we can’t really get a sense of this number—it’s still well beyond our normal human comprehension to try to imagine what a million is, much less a quintillion.

A quintillion is a million million million.

This analogy works because we’ve taken something from the world of our regular experience—the amount of grains of sand in the world—and asked us to think about that unimaginably large number for a second. We’re asked t…