Why Does Thunder Always Come After Lightning?

Lightning and thunder happen at exactly the same time. So why does the flash always arrive before the boom? In this episode of Why Though?, Dr Matt Agnew explains how static electricity builds up inside storm clouds, what lightning actually is, why thunder is the sound of super-heated air exploding outward, and how a simple counting trick lets you measure how far away a storm is using nothing but your eyes, ears, and a few seconds. **What you'll learn:** - Static electricity happens when electrons jump from one surface to another... like the zap from a doorknob after shuffling across carpet in socks - Inside storm clouds, ice and water particles bump and swap electrons until a massive charge builds up - When the charge gets big enough, it jumps to the ground as a giant electrical spark... lightning - Lightning heats the surrounding air hotter than the surface of the Sun, so fast the air explodes outward as a shockwave... and that shockwave is thunder - Light reaches your eyes almost instantly, but sound travels about one kilometre every three seconds - That gap between flash and boom is how far the storm is from where you're standing **Key Science Ideas:** - Electron: A tiny particle with a negative electric charge - Static electricity: Built-up charge that can suddenly discharge... the giant version is lightning - Electrical discharge: Charge moving rapidly to balance itself out - Shockwave: A fast-moving pressure wave made when air expands suddenly... thunder is exactly this - Speed of light vs speed of sound: Light arrives almost instantly, sound takes about three seconds per kilometre **Fun Experiment:** The Balloon Static Trick Blow up a balloon and rub it on your hair or a dry jumper. Hold it close to your hair and watch the strands lift up toward it. That's static electricity... the same force that builds up inside storm clouds, just in a much safer, much smaller version. No storm required. Flash-to-Bang Storm Distance Trick Next time there's a storm outside, watch for a lightning flash from indoors. Start counting... one, two, three. When you hear the thunder, stop and divide your number by three. That's roughly how many kilometres away the lightning struck. Three seconds is one kilometre, six is two, nine is three. If thunder follows almost immediately, the storm is very close... stay inside and away from windows. Why Though? The show for little scientists who love asking big questions. Follow or subscribe so you never miss an episode. Follow Dr Matt Agnew:  Instagram: instagram.com/drmattagnew  TikTok: tiktok.com/@drmattagnew  YouTube: youtube.com/@whythoughpod  Website: drmattagnew.com Find Why Though? podcast across the internet and share with your friends! Instagram: instagram.com/whythoughpod TikTok: tiktok.com/@whythoughpod Facebook: facebook.com/whythoughpod * * * Hosted on Acast. See acast.com/privacy for more information.