Some days, it seems like there are no mysteries left in our everyday lives. Our diets are dissected to the smallest element, there are countless books on how to raise our children and train our pets, and if we have questions, we can just turn to the Internet to find the answer. However, there are a few things left in our everyday lives that still have the experts stumped.

10.Why Do Hiccup Cures Work?

Hiccups are weird things, and we're not even sure why they happen. There's no real, practical reason for a hiccup, and we don't know why all of our tried-and-true hiccup cures work. Everyone has their favorites, from eating a spoonful of sugar to holding your breath until the hiccups stop. There are so many ways to get rid of a hiccup that no matter where you are when you get it, someone will have a suggestion for making it stop. It turns out that none of the cures are guaranteed to work for everyone, and there's not much scientific support for any of them. As for the ones that do work? Well, don't really know why they do.

Hiccups are essentially caused by the diaphragm having a spasm, which can be caused by anything from laughing to medication. Stopping a hiccup seems to rely on a couple of different things. Raising the amount of carbon dioxide in the blood seems to have some success in stopping hiccups, but no one's sure what that has to do with the process. Other somewhat successful remedies work by impacting the vagus nerve, which is involved in making sure we don't try to breathe and swallow at the same time. We don't know what that has to do with the diaphragm, either, but that seems to be why things like pressing on your eyes or pulling your ear help—those actions stimulate the nerve. Another method that's been found to cure hiccups is, bizarrely, rectal massage. Used as a cure for an extreme case of the hiccups in 1988, its success was once again traced back to stimulating the same vagus nerve.

9.Why Are Moths Attracted To Light?

We've all watched it happen, and chances are we never really thought about it that much. Bugs—particularly moths—are attracted to light, but why? It's the principle that many bug traps and zappers are built on, but no one knows just why it works. There are a couple of different theories about why moths are attracted to light, but there's not even one that stands out as a front-runner. In fact, there are pretty convincing arguments against all of them.

One theory suggests that only man-made, artificial lights attract bugs. Presumably, there's something different about artificial light that interferes with the bugs' ability to navigate, but we don't even know whether bugs are using light as a navigational aid. It's also been suggested that moths may be confusing the frequencies of artificial lights with pheromones given off by willing mates, but there's nothing to really support that theory, either. Researchers have found that it's a pretty bizarre behavior, specifically because it seems to cross species but also works against the survival of those species. In spite of the kamikaze behavior that could be expected to discourage the practice—or at least kill off the part of the population that does it—it's still a major behavior pattern.

8.What Is Foam?

Every time you wash dishes or lather your hands with soap, you're creating one of the most mysterious household compounds: foam. Foam isn't classified as a liquid, a gas, or a solid, but it's all three at the same time. Different substances form different types of foam that all seem to work differently. There's not much that's actually known about the physics of what forms this weird cohesion of matter states or how we can predict what type of foam will be formed from what type of substance.

Most foams are made up primarily of gas in between bits of liquid, but there's no mathematical formula for discovering how a foam will behave. Some foams are stiff, like shaving foams, while others are delicate, like soap bubbles. The size of the bubbles doesn't seem to have any impact on how the foam behaves. The reason we haven't been able to learn much about foam is a weird one.Foam bubbles are inherently oddly shaped. The critical point of foam, defined as the moment when all the bubbles in the foam are perfectly spherical, is impossible to achieve on Earth because of gravity. Gravity pulls foam bubbles downward, and its impact is so great that even in a layer of foam just a few centimeters thick, there's a definite difference between the shape of the bubbles at the bottom and the top. This makes it impossible to perform experiments on foam without changing what it is.

7.Why Does Static Electricity Happen?

It's a mildly annoying occurrence that usually happens when the weather's dry and you've done something like walking across a carpet. While we know how static electricity builds up, the question of why it happens is a surprisingly complicated one, with a weirdly elusive answer.

The problem in finding an explanation happens when one of the materials involved is, theoretically, an electrical insulator. There's no confirmed reason for why an electrical charge should be transferred from or to an insulating material; an insulator, by nature, shouldn't allow this. The problem is further complicated by the fact that different materials and conductors have different mechanisms for the cause, buildup, and transfer of static electricity.A static electric shock can also occur between two objects made of identical materials, which makes the phenomenon even stranger. In theory, the difference in properties should be what makes the electrical charge jump from one material to the other, but experiments performed by rubbing two identical materials together have shown that static electricity still passed between the two objects. Currently, there are no satisfactory answers from the fields of physics or chemistry, suggesting that it's actually a way more complicated phenomenon than either can account for on their own.

6.Where Did Dogs Come From?

They're some of our most constant companions, but there's a lot we don't know about when dogs were first domesticated, where the process happened, and what the first domesticated dogs even were.

Studies on the subject have proven highly inconclusive, with estimates for the first domestication ranging from 9,000–34,000 years ago. Not only is that a huge gap, but it leaves a lot of unanswered questions as to how it happened. Dogs on the most distant end of that scale would have been associating with hunter-gatherer groups, while the more recent instances of domestication would have been happening when the human race had already discovered agriculture and settled into a more sedentary lifestyle.Researchers from the University of Turku have isolated DNA from some of man's early canine companions with some staggering implications. Some of the oldest DNA samples were taken from dogs that were living alongside humans around 33,000 years ago and were traced through to dogs that lived in Greenland about 1,000 years ago. But this particular DNA seems to be unrelated to today's dogs, and it's now suggested that some of the “dogs” that were domesticated for thousands of years weren't the same as today's dogs and were instead a sort of sister species. Ancient dogs have been found in Europe, the Middle East, and Asia, but it's still not known if the idea of domestication spread from one area to the other or occurred independently in all areas. If it did, it's not known who was first.