The guy across the alley has what I believe to be a sodium vapor lamp on his garage. It doesn’t function right, and seems to be what I could call, burning out. But I don’t totally understand what that means inside the bulb. It’s on brightly for a second, goes to a bright pink/yellow/orange - the color I associate with sodium vapor lights - and then, after about a minute, suddenly dims, and there’s just a filament (no, but looks like) that glows dim orange, and then, a minute or so later, it goes on bright again. Seems to be failing, but it’s been happening for a year or so. What’s happening inside the light?
There’s actually quite a lucid description of end-of-life failure for sodium vapour lamps on the Wikipedia page about them - here: Sodium-vapor lamp - Wikipedia
Basically, some of the sodium reacts with the electrodes and gets locked up, unavailable for use in the lamp and this causes them to only be able to work at the bottom end of their warmup cycle - so they switch on, warm up, fail out, cool down, start working again, etc.
Your interpretation is most helpful. thanks