> ## Content Index
> Fetch the complete content index at: https://www.cascadepbs.org/llms.txt
> Use this file to discover other available public pages before exploring further.

# Glass is Solid… So Why Is It Clear?
- URL: https://www.cascadepbs.org/show/its-okay-be-smart/episode/why-the-heck-is-glass-transparent-escqxr/
- Published: 2024-04-02T23:16:44.000Z
- Updated: 2025-08-20T09:54:42.000Z
- Description: Glass is made of sand, which is a kind of rock. But glass is transparent. We explore why!
- Author: Cascade PBS Staff
- Tags: Be Smart, Season 8, Episode 25, #ZZZ_Episode_26821cab-44fe-4eea-91d7-2b7520785286, #episode, #ZZZ_Show_dc38a6e9-266e-43c1-b647-45e7445fad27, #v1.16

Glass is made of sand, which is a kind of rock. But glass is transparent, and rocks aren’t transparent. What’s up with that? Why is glass clear? And why can I sit on a chair? And why can we touch anything? Today we zoom down to the weird world of electron clouds and quantum touching to find the answers.