Incandescent bulbs in teaching

[Orodruin]

This thread got me thinking. Incandescent light bulbs were soft banned (as in, cannot be sold anymore) in the EU in 2016 and - if my google-fu is to be trusted - last year in the US. If you go to any store selling bulbs, all of them are LED, which makes sense both from many perspectives.* We are soon going to face a generation of students who have never in their life seen an incandescent bulb. Meanwhile, they are typically used as examples in many physics classrooms.

A couple of discussion points:
How should teachers deal with this in the coming years?
Do we need to start introductory classes by explaining what an incandescent bulb is?
What happens with the laboratory experience when physics student labs run out of bulbs (they tend to break) and cannot obtain more?
Should we simply phase out the incandescent bulbs from the curriculum?


* Anecdotally, we were visiting my in-laws in Spain recently with temperatures soaring towards 40 °C. Their second home is sparingly used and therefore was still all incandescent bulbs. It felt slightly absurd to be in Spain in summer, inside with the window blinders shut in almost complete darkness as turning the lights on would heat the house too much. Took a day or two to change all the lights in the house for LEDs.

 

[vela]

Apparently, there are still some specialty bulbs that haven't been banned in the US.

https://www.cnn.com/2023/08/01/business/incandescent-light-bulb-ban/index.html

 

[Orodruin]

Apparently, there are still some specialty bulbs that haven't been banned in the US.

https://www.cnn.com/2023/08/01/business/incandescent-light-bulb-ban/index.html

That doesn’t really address the questions in point though, ie, that students will generally be unfamiliar with the incandescent bulb.

 

[DaveE]

That doesn’t really address the questions in point though, ie, that students will generally be unfamiliar with the incandescent bulb.

Just like they were 10, 20, or 30 years ago. If you want to teach about incandescent bulbs, you will still be able to buy specialty bulbs for quite a while. Lots of equipment (microscopes, etc.) still need them. Afterall, I can still find nixie tubes on eBay. They just want to make it harder for homeowners shopping at the hardware store. OTOH, if you expect students to come to class with any knowledge of how the light in their bedroom is made, you may be disappointed, regardless of the technology. They'll tell you it's from switching a switch on the wall by the door.

 

[Orodruin]

30 years ago

That was probably around the time I started learning and I think myself and my classmates had at least some basic understanding about the filament glowing hot because of the energy dissipated in it.

Even if it still works as a demonstation tool, the connection to how light is produced in homes is lost. I feel that to at least some extent that will diminish the pedagogy. You can’t say ”this is how we make light at home”. That process of course will involve diodes which is not really your typical introduction to circuits.

 

[DaveE]

That was probably around the time I started learning and I think myself and my classmates had at least some basic understanding about the filament glowing hot because of the energy dissipated in it.

Even if it still works as a demonstation tool, the connection to how light is produced in homes is lost. I feel that to at least some extent that will diminish the pedagogy. You can’t say ”this is how we make light at home”. That process of course will involve diodes which is not really your typical introduction to circuits.

That is the nature of technology advances. Yes, I had to learn about vacuum diodes and triodes as an undergrad, but I always thought of them as if they were a strange version of MOSFET. All of these devices are complex enough that study is required regardless. I found the I-V characteristics of incandescents a bit confusing even later in my career; a complex non-linear thermo-electric device.

My big complaint are all of the very basic circuit questions that use "light blubs" as if they are resistors. I guess they think it's easier because students had light blubs at home? But in reality, those are very complex circuits. Invariably the "correct" answers are actually wrong.

 

[kuruman]

How should teachers deal with this in the coming years?

I think that the "this" that teachers have to deal in the coming years goes beyond light bulbs and how they work. Clockwise and counterclockwise are becoming meaningless as are traditional clocks.

Also anecdotally, I was recently in a waiting room when a twenty-something asked me if I know what time it is. I was not wearing my watch so I point to the large (analog) clock on the wall above the receptionist's desk saying "There is a clock over there." He looks at me exasperated, moves his knapsack from the seat next to him to the floor, unzips a pocket, pulls out his cellphone, looks at it and nods his head without another look in my direction. I was impressed.

 

[Orodruin]

Clockwise and counterclockwise

I did not consider this for the simple reason that we do not say that in Swedish. We say essentially with-Sun and counter-Sun. The Sun is difficult to ignore unless young people stop going outside oh wait!

 

[berkeman]

Clockwise and counterclockwise are becoming meaningless as are traditional clocks.

Also anecdotally, I was recently in a waiting room when a twenty-something asked me if I know what time it is. I was not wearing my watch so I point to the large (analog) clock on the wall above the receptionist's desk saying "There is a clock over there." He looks at me exasperated, moves his knapsack from the seat next to him to the floor, unzips a pocket, pulls out his cellphone, looks at it and nods his head without another look in my direction. I was impressed.

I was shooting basketball hoops at a local park recently when a teen came up to me and asked me what time it was. I said that I leave my watch on the sidelines with my towel when I'm shooting, but he was welcome to go over and check the time. He replied that he did not know how to read an analog watch (which surprised me!), and I said "Don't worry, it's a digital watch."

He walked over and looked at my watch, and asked "What time is 1315?" (I forgot that I use military time on all of my clocks and watches...)

 

[kuruman]

He walked over and looked at my watch, and asked "What time is 1315?" (I forgot that I use military time on all of my clocks and watches...)

I can imagine the continuation of this.
You (seizing the teaching moment): Just subtract 1200 from 1315.
He: Can I borrow your calculator?

 

[gmax137]

Should we simply phase out the incandescent bulbs from the curriculum?

This is an interesting issue. When many of us here were in school, lightbulbs were ubiquitous and I remember many "electricity" lessons using "lantern" batteries, bell wire, knife switches, and flashlight bulbs.

Apparently the lantern batteries are still available, but at close to twenty bucks!

I do remember a bunch of these home experiment setups started with "get an ordinary buzz coil, and bla bla bla..." Well those things* were common garage detritus in the 1950s but now? I bet even the high school science teachers don't know what they are. I'm sure nobody designs lessons around them.

* https://en.wikipedia.org/wiki/Trembler_coil

 

[MidgetDwarf]

Stock up!!!