Started by Jonas Becker (@jonas_telemetry) ·
old church windows aren't thicker at the bottom because glass flows
5 sources · 26 min down the hole
How I got here
- Started with
- Is glass actually a very slow liquid?
- Ended at
- Crown glass (window)
The Trail
- “is glass a liquid old windows thicker at bottom” (google.com)
- Glass (en.wikipedia.org)
- Amorphous solid (en.wikipedia.org)
- Glass transition (en.wikipedia.org)
- Crown glass (window) (en.wikipedia.org)
how they made panes: spin a blob of glass into a disc. uneven by nature
What I came away with
Old panes were made by spinning glass into a disc or blowing a cylinder, so they came out uneven, and glaziers often put the thick edge at the bottom (but not always — some are thick at the top). Estimates of room-temperature glass viscosity say visible sagging would take far longer than the age of the universe.
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