10 Important Questions No One Knows The Answers To

It's often said that the only things we know for sure are death and taxes, but when it comes to scientific research, it seems there are a few things that even scientists can't suss out. Sure, there are plenty of questions that have been answered - like what causes autism and how many stars exist in the universe. But then there's this other side of science: a vast frontier of unanswered queries with entire teams focused on getting to the bottom of them.

In celebration of these unsolved mysteries from nature and science, we've compiled this handy list which covers ten important questions no one knows the answers to yet - from where all our missing socks go to why humans can't hear ultrasound. Fancy the prospect of all this being revealed to us tomorrow? Read on and find out.

TEN PROBLEMS UNANSWERED

1. Where do missing socks go?

In an interview with botanical scientist Robin Leake, he said that the study of socks has made him think about where lost items go. In his own home, he's always puzzled by the missing sock mystery, saying, "Sometimes I wonder if it is the same sock that goes missing over and over again or if there are many socks out there in a parallel universe where I have many different pairs of socks." To find out what's going on with our missing socks, he wants to collect some more data.

2. Why is time moving forward?

What makes time tick? When we give more thought to this question, it turns out that even asking why time moves forward is a meaningless question. Time doesn't move forward in space, so the only explanation is that it's on a wheel. Physicist Sean Carroll - who has studied this and other questions - said in an interview with BBC that the answer to this is: "It is only moving forward if you're moving. And when you're not moving, there is no time."

3. Why don't we hear ultrasound?

New York Times recently speculated that humans cannot hear ultrasound because our brains can't process it fast enough. This isn't new, however; people have been wondering about this since forever. In fact, a school of thought suggests that neither can mice hearing ultrasound at all (although some argue for mice being able to hear it). Why? According to University of Wyoming's Sara Santos-Barreiro, mice may have had to "evolve a mechanism that lets them block out sounds that could interfere with their ability to hear predators."

4. Does the moon move too quickly for Earth's gravity?

This goes back centuries - since the time of Galileo and Descartes. If you look at it from the point of view of an observer on Earth, you'll think the Moon is moving much faster than it actually is. You might also think that only has a gravitational pull towards Earth. But as reported in Space.com, the Moon's gravity pulls equally on the Earth and everything else around it - including itself. To understand this, ask yourself why the Moon doesn't go crashing into Earth. The answer is that because it's moving faster than Earth, it actually falls away from us.

5. Why are there so many more men than women?

The human species is inherently sexual and reproduces through reproduction. But we're still puzzled by how this process works for humans - especially when it comes to gender (i.e., why are there so many more men than women?). This has puzzled scientists for centuries, and some believe that men's tendency to live shorter than women could be the key to answering why this is.

6. What is the ozone layer?

This one's a bit complicated, so we'll just break it down for you. The ozone layer is in our atmosphere, and it's what protects us from the sun and ultraviolet radiation. It helps slow down global warming by letting UV radiation pass through it but not letting the heat through (it lets the heat travel in a straight line while keeping light contained). Scientists have been studying this for decades, but no one has yet discovered what exactly is protecting the ozone layer.

7. Why are there so many missing galaxies?

Our universe is vast, and it's full of huge amounts of scientific phenomena we don't know about. As reported by New Scientist, the number of galaxies that are vastly greater than our own can be estimated at over 10 quintillion - that's 10 followed by 21 zeroes. It's not just the number, either; there are also discrepancies regarding how many planets were in these galaxies when they were formed. Because of this constant discrepancy with scientific findings, scientists have used several different methods to find more information about the universe.

8. Why are there fewer left-handed people?

When you look at your own hand, you'll notice that it's the same for right- and left-handers. But when you look at other people, many of them have an opposite preference - they're right-handed. The explanation to this has come in due time, but it's difficult to say exactly what is going on here. A theory suggests that in the past, our environment was different so everyone had the same preferences in their hands - but now we might be making a comeback by going against what was naturally normal in our ancestors' times.

9. Why is gravity so weak?

It's an enormous question, and we've been trying to get to the bottom of it for centuries. Our scientists have already found out all they could given our current state of technology, but they've not been able to figure out what's going on with gravity. Albert Einstein said that "there is no force like gravity in the universe," and that's why it has so much power over all of us. That also means, however, that it must be very weak compared to other forces in the universe - like electromagnetism. Theories suggest that there is only one thing keeping it strong enough (scientists are still trying to figure out exactly what this thing is).

10. Why did the dinosaurs die out?

There are more than a few theories about why the dinosaurs died out, but there's still a lot to be researched. One theory suggests that the real culprit was not an asteroid crashing into Earth but volcanic carbon dioxide that caused temperatures to rise and destroyed the ecosystem they depended on. Another theory suggests that their diet played a role in their extinction they had been eating plants for nearly 170 million years when there just weren't enough left on Earth.

Finally

We're humans, and we'll never stop questioning. We will continue to build our knowledge of things through all the great minds that have come before, and we will get it right - someday. Even after all these centuries of questioning, we still don't know much about our universe; these are just a few of the things that have perplexed scientists for decades. As we get more advanced as a species, however, we will continue to find more answers - and more questions!