Cracked Knuckles
Why do your joints crack sometimes? Find out in this episode.

Why do your joints crack sometimes? Find out in this episode.
Why does rust form? Find out in this episode.
Why do eyes sometimes appear red in photos? Find out in this episode.
Why do you get a suntan or a sunburn after being in the sun for a long time? Find out in this episode.
Why do pain relievers work? Find out in this episode.
Why do you snore? Why does it get worse as you grow older? Find out in this episode.
Why are all snowflakes different? Find out in this episode.
What is coughing? What makes you cough? How can you stop coughing? Find out in this episode.
Why do leaves change colors in the fall? Find out in this episode.
Why do the northern lights happen? Find out in this episode.
Why do ice cubes make a crackling sound when you put them in water? Find out in this episode.
What is static electricity and why does it happen? Find out in this episode.
What is a SIM card and how does it work? Find out in this episode.
Why do your ears ring? Find out in this episode.
Why do mosquito bites itch? Find out in this episode.
Why do you blink when you hear a sudden, loud noise? Find out in this episode.
Why is there oxygen on the International Space Station? Find out in this episode.
Why are you able to view websites? How does the Internet work? Find out in this episode.
Why do you hiccup? Find out in this episode.
How does a letter get from one side of the country to another? Find out in this episode.
What is the water cycle? Find out in this episode.
Why do your ears pop on airplanes, and why might they not pop? Find out in this episode.
Why is the sky blue? Where do the colors of the sunset come from? Find out in this episode.
Why does everyone associate red and green with Christmas? Find out in this episode.