What's the biggest number? Who was the first mathematician? Why is seven a lucky number? Why is fifth grade math so hard? We're tackling something new: questions about math! With us to offer some answers and some mind-blowing concepts is author Joseph Mazur.

Why do we have daylight saving time? And why are days longer in summer and shorter in winter? Daylight saving time is really just a trick. At least, so says Michael Downing, author of Spring Forward: The Annual Madness of Daylight Saving Time. He's our guest in this episode and he explains the reasons behind this semi-annual ritual of moving the clocks forward and back.

On this special episode of But Why, we're going to introduce you to some of our kids podcast classmates. We've all gotten together to create one big podcast episode that gives you a little flavor of what each one of us is all about. Enjoy!

Why do leaves change color in the fall? Why are leaves green? Why don't leaves turn all of the colors of the rainbow? In this episode of But Why, we're talking about fall leaves, and how trees go from green to fiery red, orange and yellow.

This episode of But Why is a serious one. We're talking about death. Why do people die when they get too old? What happens to people when they die? What does it feel like when you're dead? Our guide is Jana DeCristofaro from the Dougy Center: The National Center for Grieving Children in Portland, Oregon, which supports children and families facing serious illness or coping with the loss of a family member.

Is it OK to do something that you were told not to do and then never tell anybody? We tackle that question from 10-year-old Finn from Seattle. Also in this episode: why do people make really bad choices and want other people's lives to be harder? Download our learning guides: PDF | Google Slide | Transcript

In the last couple of weeks, two big hurricanes have hit parts of the United States and Caribbean islands. In this episode we answer questions from kids who have been hearing the news and wondering: How do hurricanes form? Why do hurricanes strike Florida? Why do hurricanes have names? We speak with atmospheric scientist Shuyi Chen of the University of Washington.

How is glass made? Why does glass break? Why do bubbles pop? What's it like inside a bubble? We make everything clear in this episode! Our questions are from kids in Arizona, Brazil, California and Cambodia. Transcript

Why do bees pollinate? How do bees make honey? Why do bees have stingers? Why do bees die when they sting you? What's the difference between a bee and a wasp? Does honey have healing properties? Vermont farmer and beekeeper John Hayden of The Farm Between answers all of your bee questions! And we learn about one curious kid's app, which he hopes will help save pollinators.

In this episode, we're answering some of our frequently asked questions, the questions we hear a lot from all of you: why are there so many different languages? Why do we get hiccups? Why do our fingers get wrinkly in the tub? Why are plants so many colors? Why do leaves change colors in the fall? Why is the sky blue?