Starship Asterisk*

The mention of photons reminded me of the photon torpedoes used in the Star Trek series. Very handy weapons! Sorry for bringing the interersting scientific debate down to a low level but I thought a bit of lightness (photons - light, ) may bring a needed .

geckzilla wrote:I totally agree the theory vs experimental thing and I understand the segregation for that purpose but having a simple name (light) to call all of it would make it a lot friendlier to people and remind them that they can use the analogy of visible light, which most people understand on a basic level, for all other types of electromagnetic radiation. Calling it radiation, submillimeter, radio, x-rays, etc. creates technical barriers for lay people to understand.

Try it. But for me, "electromagnetic radiation" seems the ideal choice. Using just "light" is going to be ambiguous or confusing in many cases. I go for clarity over lack of scariness.

You've been a physicist for so long that "electromagnetic radiation" isn't difficult at all. I am still struggling with the fact that light is the joining of electrical and magnetic forces into one. And radiation to any normal person just brings up thoughts of Chernobyl, that green glowing stick that gets stuck to Homer Simpson's back, and atomic bombs.

geckzilla wrote:You've been a physicist for so long that "electromagnetic radiation" isn't difficult at all. I am still struggling with the fact that light is the joining of electrical and magnetic forces into one. And radiation to any normal person just brings up thoughts of Chernobyl, that green glowing stick that gets stuck to Homer Simpson's back, and atomic bombs.

I remember when CD players came out, and were the first common consumer device to contain a laser (hardly anybody had LaserDisc players). As required, the CD players had the standard laser warning label, cautioning the user about "laser radiation". Some people got very concerned about that, because, as you say, they couldn't separate "radiation" from nuclear bombs. A similar issue came up with microwave ovens.

But people seem mostly to have gotten over that. I'm all for clarity in scientific discussions with non-scientists, but not to the point of modifying standard language in a way that actually makes things less clear, which is what I think happens when we use "light" instead of "electromagnetic radiation". There is value in teaching the idea that "light" as people understand it represents just a portion of the entire spectrum, just like radio, x-rays, etc.

I don't think people are over it at all. If you labeled all cell phones as radiation emitters, people would freak out. You could even label it like "This cellphone emits harmless radiation." and people would be even more wary. There is no shortage of websites out there purporting the dangers of microwaves. I know a family here who doesn't have a microwave oven because they think it's not healthy to eat microwaved food.

geckzilla wrote:I don't think people are over it at all. If you labeled all cell phones as radiation emitters, people would freak out. You could even label it like "This cellphone emits harmless radiation." and people would be even more wary. There is no shortage of websites out there purporting the dangers of microwaves. I know a family here who doesn't have a microwave oven because they think it's not healthy to eat microwaved food.

Oh well. I make a distinction between simple language and dumbed-down language.

Well, why is it ok to say UV light, visible light, and infrared light, but not, say, microwave light? Is it just because this form of EM radiation no longer works with familiar things such as objects made of materials which to our eyes look like lenses and mirrors? Are there not other mediums which can be used as unconventional lenses for other kinds of light even if our eyes can't see it happening?

geckzilla wrote:Well, why is it ok to say UV light, visible light, and infrared light, but not, say, microwave light? Is it just because this form of EM radiation no longer works with familiar things such as objects made of materials which to our eyes look like lenses and mirrors?

Exactly. EM energy in these bands behaves fundamentally the same way.

Are there not other mediums which can be used as unconventional lenses for other kinds of light even if our eyes can't see it happening?

See, this is where the confusion starts. "Other kinds of light"? What does that mean? If you're using "light" as a synonym for electromagnetic radiation, that's certainly sloppy. I'd never say "other kinds of EM", because there's really just one kind. Or are we talking about different parts of the spectrum? Confusing.

In the lab, people have come up with clever ways of manipulating various wavelengths in unconventional ways. For example, peculiar metamaterials that focus microwaves in a way analogous to a refractive material. These tricks serve to demonstrate that all electromagnetic radiation is subject to the same laws of physics. But usually, that's all they demonstrate. The reality is that different parts of the electromagnetic spectrum interact with physical bodies in very different ways, which is why we have developed natural boundaries around various wavelengths and find it convenient to label these parts differently, as well.

Sloppy? But that's how it's been used the whole time. UV is a kind of light. Infrared is a kind of light. And then everyone's favorite, the human retina-friendly visible kind of light. But, yes, I am using it as a synonym for electromagnetic radiation. I get real tired of typing that word out, too. Anyway, if I'm sloppy then so are the people telling me that UV and infrared are light.

geckzilla wrote:Sloppy? But that's how it's been used the whole time. UV is a kind of light. Infrared is a kind of light. And then everyone's favorite, the human retina-friendly visible kind of light. But, yes, I am using it as a synonym for electromagnetic radiation. I get real tired of typing that word out, too. Anyway, if I'm sloppy then so are the people telling me that UV and infrared are light.

The parts of UV and IR close to the visible spectrum are meaningfully called light. Extreme UV and far-IR are only marginally so. These definitions actually make good physical sense, which is why I would encourage their use. Calling cosmic rays or radio waves "light" is just adding confusion, IMO.

But like I said, try it. You're not really wrong, just unconventional. I'll stick with less ambiguous usage, myself.

This is interesting but not light reading!

Just for a bit of light relief here's a question. How do you easily make a faulty lamp work?

Answer: Raise our hands, as many hands make light work. Oops, I tried to hide that but it did not work.