In response to Facts of Light part 1

[Diablo]

Hi Sanjay,

Let me start by thanking you for your series of articles over the years... they have been very helpful and informative.

Additionally, in general, your article "Facts of Light Part 1" is very good, however, the engineer in me demands a response to the following:

Now we can begin to understand why the red light gets absorbed quickly in water as a function of depth. It has less energy, and this energy gets absorbed and dissipated quickly; hence, the red photon does not penetrate deeply into the relatively dense medium of water.

This is patently untrue. UV-C, for example, has more energy per quantum than infrared, yet is absorbed significantly more than infrared.

Quantum interaction with a medium is not ballistic in nature... as I'm sure you're aware, a quantum of energy is either absorbed or it is not (as demonstrated by Einstein's photo electric effect). In the case of water, absorbtion is determined by the interaction of the energy quanta with the vibrational resonant frequency of hydrogen-oxygen covalent bonds. An excellent reference is here: Molecular Vibration and Absorbtion

Whilst I expect that this is well beyond the level of discussion you were targeting, it renders the quoted statement as misinformation, and you would have been better to ommit it.

Regards,

Mark Chapman

 

[Sanjay]

Mark:

Thanks for pointing this out. You are right that comment should not have been made.

One of the problems with trying to simplyfy and explain concepts at a level of beginer understanding is that one often makes statements that are only partially true and ignore some of the nuances. I need to watch out for that.

Would you like to review the next part of this series for me ?

Thanks,

sanjay.

 

[Diablo]

Hi again Sanjay,

I would be happy to assist in anyway I can, however undergraduate quantum mechanics and a passing interest in solid state device physics hardly qualifies me to edit your work!

In my first job out of uni I was a technical trainer for Ericsson, so understand the difficulties of exposing tough topics to audiences with little background; I think you do a superb job...

Respect.

Mark

 

[Skipper]

Thanks for your input, Mark. I've corrected the page based on your observation.

 

[Highlander]

Gentlemen,
This is the most respectable discussion of a counter point that I have ever seen on Reef Central.
It was a delight to read something other than much of the anecdotal, self justifying, self promoting, argumentative banter that one reads all too often.
Thank You.

 

[Skipper]

Mark: the next article is on its way to your inbox.