Why Can You See Through Glass but Not Through Foil?

Light does not pass through gaps. It passes through what cannot absorb it. — Chapters 0:00 The Foil and the Window 1:09 Seeing Through Is More Than Light Getting Through — Four Possible Journeys 3:18 Why Light Interacts with Electrons — From Atoms to Energy Bands 5:05 Why Ordinary Glass Is Clear — and Why We Can See It at All 7:33 Why Metals Shine — and Color Is Selective Disappearance 9:13 Clear Matter Divided — Sugar, Ice, Snow, Clouds 10:36 Wet Paper and Matching Materials — Making Boundaries Disappear 12:05 Thickness Is a Decision — and Clear Is Never Perfect 13:12 The Surface Can Destroy Clarity — Refraction Preserves and Distorts 14:32 Three Tricks at the Boundary — Trapped Light, Polarization, the One-Way Mirror 16:37 Transparent to Whom? — Windows in Glass and Sky 18:08 The Answer — Matter Edits the Signal 19:56 After the Answer — Transparency in Living Things 21:19 Final Reframe — Matter That Preserves a Story — A new episode every week. This channel takes one ordinary thing and follows it until it stops being ordinary. If you spotted an error, say so in the comments. Corrections get pinned. — Credits Crinkled Aluminum Foil (cropped): Tony Webster from Minneapolis, Minnesota, United States, via Wikimedia Commons, CC BY 2.0 (https://creativecommons.org/licenses/by/2.0/) · https://commons.wikimedia.org/wiki/File:Crinkled_Aluminum_Foil_(45451376615).jpg Flight (cropped): Jason Jacobs from Honolulu, USA, via Wikimedia Commons, CC BY 2.0 (https://creativecommons.org/licenses/by/2.0/) · https://commons.wikimedia.org/wiki/File:Flight_(35508222054).jpg Just a refraction (cropped): Federico Poni, via Wikimedia Commons, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · https://commons.wikimedia.org/wiki/File:Just_a_refraction.jpg New Mexico - North America - Radio Telescopes - Radio (cropped): CGP Grey, via Wikimedia Commons, CC BY 2.0 (https://creativecommons.org/licenses/by/2.0/) · https://commons.wikimedia.org/wiki/File:New_Mexico_-