Making money can be reduced to a simple method: solve a problem. Figuring out an easy, quick, and profitable solution to a ubiquitous issue is the basic equation that any business follows. Either being the first to devise a solution, or coming in afterward to improve upon it — this is how entrepreneurs with simple ideas turn their concepts into successful companies.

With that in mind, looking for a problem to solve is often a huge hang-up for would-be entrepreneurs. After all, our modern lives are pretty cushy — most people don’t live in constant fear of being devoured by predators, starving, or really anything else life-threatening. Most of our problems have been taken care of, and with the advent of the Internet and mobile technology, almost anything we want or need is a few taps away…

Sound like something you’d be interested in? Put on your thinking cap, because these five problems are about as big and complicated as it gets.

1. Energy storage
2. Artificial intelligence
3. Space exploration/resource capture
4. Water scarcity
5. Food Production