While it may seem like scientists have everything figured out, there are still tons of questions out there that science is struggling to answer. Often a new discovery creates more questions than answers, and can end up challenging everything we thought we knew about space, time, the world, human history, and much more. So here’s a collection of questions that are currently stumping the brightest minds on earth. Some are brand new mysteries, while others have been puzzling us for years or even centuries. Either way, you’ll be surprised at just how many basic concepts we don’t understand – at least, not quite yet.