Incandescent light bulbs (used until the mid-1990s) had a spectrum very similar to natural sunlight with large amounts of red and infrared, meaning that people living indoors with incandescent lighting up to the mid-1990s were receiving adequate red/infrared light exposure despite being inside.
factualpending
Speaker
Glenn JeffreyEvidence Quote
“if we were to go back to 30 years we would have incandescent light bulbs filament bulbs those filament bulbs are very very similar to natural sunlight they've got a big chunk of red in them an infrared so up until the mid 1990s we were actually okay”
Created: 8/11/2026, 8:02:22 AM
My Notes
Loading notes...