Cascades to Coast

What's this noise I hear about two new elements? Shouldn't all elements have been discovered theoretically a long time ago?

Theoretically, all elements can be predicted by the periodic table. All the ones that occur in nature have been "discovered" for quite a while. What we've been seeing for the last couple decades is "discovery" of new man-made elements. Typically they're produced in some kind of atom collider that creates a huge, unstable element that can be detected for a few microseconds. Imagine the difficulty of proving the existence and nature of something that exists for microseconds. Since all they really need to prove is the atomic mass, it can be done.