Understand it, don't just read it

Pick a question.

Every one is something you can poke, break, and figure out for yourself. You guess first — then watch the answer happen. Free for everyone.

ages 8–11 How does a song fly through the air into your radio? wavessoundphysics Discover ages 8–11 Why is the sky blue (and sunsets red)? lightcolorsky Discover ages 8–11 Why doesn't a whole town get sick at once? germsspreadhealth Discover ages 8-11 Why does ice float? waterdensitystates of matterice Discover ages 8-11 Why do tiny things grow huge? growthmoneymathdoubling Discover ages 8–11 Why is it hot in summer and cold in winter? spaceearthlightseasons Discover ages 8–11 Why does a heavy hammer and a tiny feather hit the ground at the same time? gravitymotionair Discover ages 8–11 Why is it so much harder to push a couch than to push a chair? motionforceinertia Discover

8 explainers so far — more are on the way.