Unobtainium Memes

The periodic table is literally a complete catalog of all elements that exist in our universe. There's no secret menu, folks! Sci-fi writers love inventing magical elements with names like "Unobtainium" or "Vibranium" that supposedly aren't on the periodic table, but that's like saying "I discovered a new color that isn't in the visible spectrum" and then just pointing at purple. If you're going to break physics, at least come up with a better excuse than "we found element #119 and it makes spaceships fly." Just say it's alien technology powered by the tears of chemistry teachers everywhere!