Wait a minute, what? That looks very very wrong. You must be wondering if the title is some horrendous typo, right? Well, let me assure you that it’s absolutely not! The sum of all natural numbers is equal to -1/12. This blog post is not just about mathematical trickery either. The equation in the title is actually a very important result used in theoretical physics, particularly in string theory. Now how can that be possible? Are physicists really that bad at mathematics? That can’t be it! What is the proof behind this? Do we ever encounter it in real life? Continue reading “1 + 2 + 3 + 4 + 5 + …. = -1/12”