Technology Connections talked a lot about this and the supposed planned obsolescence of light bulbs

https://youtu.be/zb7Bs98KmnY

TL;DW: (if I rember correctly) Bulbs with shorter lifespans are generally more energy efficient. There was good reasons to not making bulb that last forever.

This is an interesting bit:

> While it might seem astonishing that so many longest-lasting light bulbs have been so infrequently turned off, this is the precise reason for their longevity. Most of the wear and tear that leads to burnouts in incandescent light bulbs is caused by turning them on and off, not by burning them. Each time the bulb is turned on and off, the filament is heated and cooled. This causes the material of the filament to expand and contract, in turn causing micro stress cracks to develop. The more the light is turned on and off, the larger these cracks grow, until eventually the filament breaks at some point, in non-spectacular fashion, thus causing the light to burn out.

I knew running filament bulbs on low voltage is the key to their longevity, but this is another important aspect

OT: I'm curious about a long lasting bulb I have. Nothing like any of those, of course...it is just that it has way more hours on it than I'd expect based on average lifetimes of various types of bulb.

It's an outdoor security light over my garage. I don't know what technology it uses because the bulb is screwed in too tight for me to unscrew it with one of those things you put on the end of a pole to change out of reach bulbs, and I'm not agile enough on a ladder to be willing to get up on the garage roof to do it by hand.

The bulb is clear so it is not fluorescent. I think it is some kind of gas discharge lamp. When it turns on it takes a minute or so to reach full brightness.

It's been there since I bought this house 16 years ago. It's on a sensor that turns it on sometime during twilight and turns it off sometime during dawn. So figure maybe 10 hours a night average. That's over 58000 hours of on time.

But 58000 hours is over twice the average lifetime of all the likely technologies for this kind of security light except LED and it is definitely not LED. So I'm curious what technology my bulb actually uses.

The Centennial Light mentioned in this article also features in a later chapter of the wonderfully written 17776 [0]. It will take a while to get through it, but very much worth the time.

[0] - https://www.sbnation.com/a/17776-football

Very weird article. Doesn’t follow the same writing style as the rest of Wikipedia and almost every bulb story has citation needed on it.

On the subject of obsolete ways of making light, I really miss the aesthetic of the yellow low-pressure sodium lights we used to use outdoors in the UK that ate the colours out of everything. They were actually about as efficient as LEDs in terms of turning electricity into visible light but didn't last as long and eventually the last European company making them packed it in so we've more or less switched over entirely at this point. I don't really like how a lot of modern lighting tries to make night look like day, I prefer the night to look like night!

There's no reason you couldn't have monochromatic LEDs in the same colour, part of me wishes we went for that instead of white ones which are usually pretty cold and harsh though they've got a lot better on that front with the really warm white ones being quite nice.

Related: The Dubai Lamp: The “World’s Most Efficient” LED Light Bulb

https://news.ycombinator.com/item?id=25808959

I have several carbon filament bulbs in a large ornamental chandelier. They glow gently and while I have replaced every other bulb in the property (some of them many times) in just the last decade… these vintage examples just keep on running. Output light per unit of electricity is very low, but that’s not really why I chose them.

A great example of why you shouldn't manually number lists:

> The second-longest-lasting light bulb is ... and was installed ... on September 21, 1908

> Another working light bulb dating from 1908 ...

And in the next section:

> The third longest lasting light bulb began operation in 1929-30

Clearly the text from the third section onward all contain an off-by-one error, assuming there aren't any more yet-to-be-listed entries.

The world's longest-lasting light bulb website is also from another time: https://www.centennialbulb.org/

Unfortunately it looks like they took down the webcam, which is what I was looking for

Well at least I learned something new today!

And the cartel of incandescent lightbulb manufacturers that prevented longer-lasting bulbs from eroding profits: https://en.wikipedia.org/wiki/Phoebus_cartel