8 Simple Questions You Won't Believe Science Can't Answer

The field of science is capable of some amazing things, mostly because it's filled with all the Albert Einsteins and Doogie Howsers the world has produced over the centuries. But it may shock you that some of the most mundane, everyday concepts are as big a mystery to scientists as they are to the average toddler. Things like ... #8. Why We Sleep As far as we know, virtually every creature on earth enjoys a good night's rest as much as people do (though the hours we choose to sleep varies greatly). So obviously sleep must serve a key purpose for all living things, right? Well, it turns out science doesn't have a clue. What we have is a handful of proposed explanations for sleep that not many scientists can agree on. There's the theory that it's helping the brain clean house after a long day of learning. You see, your brain is constantly generating new pathways thanks to all the stuff that you see and do all day, so sleeping is when all the useless info gets tossed out. Or maybe, instead of ditching the stuff that's not necessary, the brain might be reinforcing the stuff you do need. Scientists have seen that, when rats were asleep, the same neurons fired as when they had run mazes earlier that day. That means that the rats are essentially reliving their day and "practicing" the maze. This has led Harvard sleep researchers to assert that sleep is crucial for humans to form memories and to learn. #7. How Many Planets Are in Our Solar System Since Pluto was surprisingly kicked out of the solar system treehouse, we've known that the membership of the Planets Club is subject to change at science's whim. What you may not have realized is that the current inventory of eight planets and one sun is pretty much just science's best guess for the time being. It sounds bizarre, considering you all saw the same model of the solar system in elementary school. And every time you hear anything about space in the news, it's always badass telescope this, or new photograph of faraway galaxy that. We're mapping the edge of the freaking known universe over here. There's no way anything in our own cosmic backyard is escaping our notice, right? #6. Why Ice Is Slippery Saying that ice is slippery is like saying that water is wet -- it's something we've known for as long as we can be said to have known anything. Presumably, humans as a species knew ice was slippery before we knew fire was hot, or that it existed. But ask anyone why, and they won't be able to give you any better explanation than one of those cave people would have. We just don't know why it is that you can ski on ice but not on boulders. Although at this point, most of you are probably screaming "It's water, stupid!" -- and that's more or less the answer that scientists have always concluded. Even in some modern textbooks you can still read the popular explanation: