hpr-knowledge-base/hpr_transcripts/hpr3186.txt

Episode: 3186
Title: HPR3186: A light bulb moment, part 2
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr3186/hpr3186.mp3
Transcribed: 2025-10-24 18:27:40

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This is Hacker Public Radio Episode 3186 for Monday the 19th of October 2020. Today's show is entitled
a light bulb moment. Part 2
It is the 60th show of Mr. X
and is about 8 minutes long
and carries a clean flag. The summary is
the history of lighting.
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Music
Hello and welcome Hacker Public Radio audience.
My name is Mr. X and welcome to this podcast.
As per usual I'd like to start by thanking the people at HPR
for making the service available to us all. It really is an invaluable service on these here intertubes.
HPR is a community led podcast provided by the community for the community.
That means you can contribute to why don't you pick up a microphone
and send something and it's really easy.
We'll get something that we can record on. Something as simple as a mobile phone
who's not got a smartphone these days, me.
But I'm sure most of you will have one.
Come on, pick up a microphone. You know you can.
If you all did, we'd have enough shows.
Anyway, this is a second part of my light bulb moment
podcast inspired by an email from Dave Morris.
I thought in this second part I'd really have a brief history of lighting
because it's quite surprising and quite fascinating really.
At least I think so. But then again maybe I'm just a bit sad.
Natural light first came from fire.
Then using oil and fat with a work.
Early candles used animal fat.
This smelled awful and tended to spit.
In some parts of the world they used whole animals as candles.
These early candles gave so little light
that people generally just went to bed at sunset.
Electric lighting started first by Humphrey Davy
in the early 1800s using an arc.
This was developed into commercial lighting in the 1840s.
Arc lighting needed a complex mechanism
to gradually push the context together as it burned away.
These arc lights, you probably saw these in films and black and white films.
Maybe shining lights on to planes up in the sky during World War II or something like that.
Or maybe in a Godzilla film, shining the Godzilla or something like that.
It's a big cylindrical, huge lamp.
Very elaborate, very expensive.
It used an arc processed like well arc welding.
The context basically burned away as the thing was in operation.
Making it very complex to keep the thing going.
Gas lighting started around the 1850s.
This was improved in the 1870s with the advent of the gas mantle.
My only memory of gas mantles was when we went to Caravanning
and you had the gas canister outside and you had to light it with a match.
Thomas Edison developed electric light bulb in 1879 using a carbon filament.
It took a great deal of effort to convince people to use it
because gas lighting was so well established and worked so well.
Many households in Britain didn't install electric lighting until 1930s.
Eventually, electricity won as it could be used for so many other things around the home.
The tungsten filament bulb has a filament made of tungsten.
It's a name to suggest and it's made up of a coil of coil as a coil within a coil.
This is done because the more compactly a filament can be wound,
the less heat is lost to the surroundings and the brighter the bulb will glow.
The next progression was tungsten halogen bulb.
These bulbs are more efficient and give out twice as much light as ordinary bulbs and use the last twice as long.
A major disadvantage with all filament lights is that they waste a lot of energy producing heat.
An ordinary light bulb only gives out about 10% of its energy as light.
The rest is wasted as heat.
Fluorescent neon lights were invented in 1905 by a Frenchman called George Claude.
They were used for advertising mainly in America.
These are traditional flickering flashing lights you saw on chalk windows and such like.
I don't know when that would be.
We're put to devastating use in America all around America really.
The first fluorescent light was introduced in 1939.
It uses the same principle as a neon light but incorporates a filament at both ends.
It is filled with argon and mercury vapor.
It mainly gives off ultraviolet light.
The tube is coated on the inside with its chemicals to convert the output to mostly visible light using a property called fluorescence, hence the name.
Fluorescent tubes are 4 times as efficient as normal incandescent light bulbs and they run cool.
The early energy efficient light bulbs were just fluorescent lights folded into a compact bulb shape.
Sodium lights used mainly in street lighting are twice as efficient again as fluorescent bulbs and they give off a rather horrible orange colour.
I can remember seeing these all over the place when I grew up.
There's probably still some of them flickering away in street lamps in the area but there's more efficient lighting now so a lot of these have been replaced.
The first commercial high pressure sodium lamps were available in 1965 from companies in the United States, the United Kingdom and the Netherlands.
At introduction, a 400 watt lamp would produce around 100 lumens per watt.
Our references from Wikipedia which I'll obviously include in the show notes.
The next big development was LED lighting which I'll cover in the next episode so stay tuned.
Okay that's about it for this episode.
I hope you found it interesting and if you want to contact me you can contact me at www.missarex.html.com.
That's MRX, AT, HPR, the art symbol, googlemail.com.
So till next time, thank you and goodbye.
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