Ever heard the claim that it’s not possible to fold a piece of paper more than 7 times? If you were to test that with a quick experiment, you’d find yourself agreeing.

Take a letter- or legal-sized paper, and keep folding it in half with your bare hands until you can’t fold it anymore. You probably won’t be able to get past fold #7, for an interesting (and mathematical) reason.

As you keep folding the paper, its thickness keeps increasing exponentially. If you start with a piece of paper that’s just 0.1 mm thick, the resulting thickness will be 0.2 mm. Fold it again, and it’ll be 0.4 mm thick. By the time you’re able to fold the paper 7 times, its thickness would be the equivalent of 128 pieces of paper.

That’s not to say, however, that paper of a different size can’t be folded more than 7 times.

In fact, back in 2011, a group of students was able to fold a piece of paper 13 times. However, the students used a piece of tissue paper 10 miles long, and it took the team a whopping 7 hours to accomplish the task.

Did you know that if you could fold a piece of paper in half 30 times, it would be thick enough to reach space? Check out the explanation (and a cool paper-folding demo using a hydraulic press) here.

Still remember your 5th-grade science classes? Test your knowledge and see if you still remember these facts and fundamental concepts in human anatomy, biology, botany, and other branches of science. Click here to try the “Are You Smarter Than A Pinoy Fifth-Grader” Challenge.