Gas Lights: How We Erased Darkness from the Night [video]
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You may be surprised to learn that street lighting (as we know it) was relatively uncommon until the mid 1800s. Up until about 200 years ago, new lighting technology developments tended to take place centuries apart. That all changed with the advent of open-flame gas lighting.
In the first video in my Story of Light series, I cover the development of gas lighting, the pros and cons of the technology, and the inventions that led to its downfall. If you know where to look, however, you can still find gas lamps today.
My dad's house was built in the mid-1990's. It has custom fluorescent bulbs that are probably rated at 5000K. They're "okay", but only because the bulbs are entirely hidden on top of cabinets or high in the ceiling, and filtered through the tan paint on the walls. I found some 2200K COB LEDs that I intend to install on those light circuits, as the other lights in his kitchen are a case study in poor lighting practices.
His kitchen has canister lights. The stickers say "max 40w", but he had 75-watt equivalent 5000K CFLs in those canisters. They were terrible. I found a box of 2700K 60-watt equivalent LEDs in his laundry room, and switched them out while he was traveling. At the time he was like, NO I'M OLD I NEED SUPER-BRIGHT LIGHTS, but now he uses those lights instead of ignoring them. They're still too bright, but at least they're usable now. I recently found some 15w and 25w incandescent bulbs: the canister lights directly above the counters would be fine with 25w bulbs.
In your future videos, I'd be interested in comments on the dark-sky movement, efforts to prevent skyglow, how people commonly use too much light at night, and the abandonment of good lighting practices in the name of energy-efficiency: glare, "daylight" LEDs, broad-spectrum streetlights, etc.
OH, and I'd be especially interested in the difference between 5000K fluorescent and supposed-5000K LED bulbs. I'm sure the spectral power distribution of the supposed-5000K LEDs is totally different than 5000K fluorescents: lots of blue with just enough ROYG to trick people into thinking it's 'white' light (LED) vs. a relatively-flat power distribution (fluorescent)?
Regarding 5000K fluorescent vs. LED, actually the fluorescent will be way more spiky, with multiple spikes. A typical daylight LED spectrum is a spike around 450 nm, then a drop, then the rest of the colors from green to red.
[0] compares some different spectra, although most modern 5000K LEDs will tend to be a bit higher in the red area. I would say the warm white LED, cool white LED, and daylight spectra are a bit exaggerated/too ideal in this comparison.
What emits most of the visible light in fluorescent vs. LED is actually almost the same thing: a phosphor that converts UV (fluorescent) or blue (LED) into white light. But the actual chemical makeup differs between LED and fluorescent.
There are some new LED technologies that flatten out the spectrum. These typically employ a violet pump (around 415 nm) or some combination of violet, blue, and cyan (around 490 nm). But it's the phosphor engineering that actually does most of the flattening. We're only just starting to see these become available in finished products, however.
[0] https://thegreensunshineco.com/wp-content/uploads/2018/09/le...