Our Answers to the Most Burning Questions of 2014

Ask Smithsonian video host Eric Schulze takes questions from our readers and answers them weekly in a series of one-minute videos. This year, we investigated the answers to everything from "What's up with willpower and why don't I have it?" to "Can cats really make rats into zombies?" Check out the top ten most popular questions of 2014 below. Have one in mind for 2015? Ask us!

1) Why don't people smile in old photographs?

2) What's a stone baby?

3) How do dolphins sleep without drowning?

4) Does the five-second rule really work?

5) How did King Tut die?

6) Why were prehistoric animals so big?

7) Where does space begin?

8) Do animals laugh?

9) Why do songs get stuck in my head?

10) Why are lakes freshwater and oceans saltwater?