My five year old is now reading fluently and as a result is asking all sorts of questions about the meanings of words. The other day, she asked why fluorescent bulbs were so named and I realized that I had absolutely no idea, so I set out to find out more about this suffix.
It turns out that -escent is used in two ways. The first relates to the play of light and color and is seen in words such as:
- fluorescent – having a type of luminescence caused by the absorption of radiation
- iridescent – having a lustrous, rainbow like play of color
- pearlescent – having a pearly luster
- opalescent – reflecting an iridescent light
- phosphorescent – the quality of luminescence without heat
- incandescent – white or glowing with intense heat
- luminescent – low temperature emission of light
The other use of -escent indicates a change of state. Something may be beginning to change, have changed slightly or resemble another object. That use gives us words such as
- obsolescent – becoming obsolete
- quiescent – becoming quiet
- arborescent – resembling a tree
- effervescent – beginning to boil or bubble
- adolescent – becoming an adult
- convalescent – recovering health gradually after being ill
- florescent – beginning to flower
Related suffixes are -esce and -escence (as in convalesce and convalescence)
I was told that a fluorescent bulb makes use of the property of change. As electricity passes through and ionized trail through the gases in a fluorescent bulb, it adds energy to electrons in some atoms. When the electricity stops, the electrons return to their starting energy state while emitting the extra energy that first moved the electrons, as photons – visible light.
Because we use alternating current, this process reverses direction, and re-charges the gases at 60 Hz – 60 back-and-forth cycles per second. A common fluorescent bulb flickers 120 times per second, alternating from one end, then the other.
I guess in this case the fluorescing is due to electric current applied directly, rather than radiation impacting a fluorescing material. In any case, the energy absorbed by the fluorescent or glowing material would still see electrons displaced by added energy, and give off photons as the added energy dissipates and the electrons return to a rest state.
I guess I would have put fluorescent in the ‘change of state’ list.
I think of pearlescent and opalescent as specific kinds of iridescent, where the appearance changes between different apparent shades of color. They shimmer, they “gleam tremulously”. It is the changes of apparent state, usually because of minor changes of viewing angle, that creates the subtle changes of appearance. I would have listed these in the ‘change of state’ list.
Wow great! I didn’t know that either.
Btw, 5 year old and already reading fluently?! A little genius you have there!
Looks like having children actually pays off by producing great post ideas… 😀
Brad, I’ll defer to your superior electrical knowledge, though these were the explanations (and the divisions) I found in my research. If anyone else has info on this, feel free to weigh in.
Jan, I’ve had a few good ideas from that source. Children can make you question the things you take for granted. 🙂
Speaking of affixes, people don’t seem to realize the great utility of the prefix dis-, which basically means “the opposite of”:
pleasure – displeasure
comfort – discomfort
Once you grasp the meaning, you can use the prefix more broadly. For example, one of my college teachers suggested that you could call any academic “Professor” because “no one is disflattered by being called a “professor”.”
Obsolescent. I had an argument quite a while back about that word. I argued that it wasn’t a word, it was just people’s ba5tardisation of the word ‘obsolescence’, and what they really wanted to use was the word ‘obsolete’. I had honestly not heard of the word until then. Needless to say when the dictionary came out, I climbed down…
Note to self: engage brain and check dictionary before arguing.
I still refuse to use it. I always prefer to write ‘becoming obsolete’ as I think ‘obsolescence’ has no place in my writing even though it’s very widely used in my tech writing field.
Leisureguy: yes, it’s a very useful prefix.
Cmdweb: I tend to use ‘becoming obsolete’ myself, as it’s clear what it means. Still nice to know the other word, though. 🙂
That’s pretty awesome. I love little nuggets of facts like this. Many times in elementary school or younger I would ask tons of questions like the one your son did. And most of the times I would never receive the answers… I can see myself doing exactly what you said. 🙂
Ah, a fellow trivia junkie. It’s fun to find out new things, isn’t it, impNERD?
I guess in this case the fluorescing is due to electric current applied directly, rather than radiation impacting a fluorescing material
No; the light comes from the coating on the inside of the tube – if you made a fluorescent lamp with a plain glass tube, you’d get very little visible light (just a dull blue glow; it’s mostly ultraviolet)