Electromagnetic absorption by water

[Andy Perrin]

The mu and alpha stuff seems to be fine, now, although I didn't check all of your conversions, just a few (which looked fine). If you want to write up the differences in absorption between water vapor, liquid water, and ice, that's fine. For example, the NIR ice peaks are shifted relative to the liquid, and I remember I did a demonstration of that with ice cubes in water for the 976nm peak.

[Stefano]

I still feel there is something else to add, the original post isn't complete yet. I will talk about ALL peaks, even the minor ones. Andy, when in the future (I am not pushing you into doing this) you will explore the other peaks, I will surely include your work. There's nothing better than images to understand things. I strongly believe that physics MUST be seen, heard and touched. You can't do experiments in math, you can't "sense" numbers, but the beauty of physics is that you can actually experience it.

 

Sadly, the real fun in the infrared spectrum begins in the SWIR range. Below that, everything just bleaches out, becomes white, transparent... but in SWIR you have absorption again. Just thoughts...

[Stefano]

A few other things... (hopefully I will stop editing my post and stop annoying you)...

 

Just to make things even nicer, should I include a table with all (available) values for all peaks from the sources listed by the creator of the first image on the original post (simply, this)?

 

I will do it probably tomorrow. I think there will be nothing more to add, at least for now. I remember Bernard posted an image with a sink full of blue water, I searched it and still didn't find it. I can search it tomorrow, no problem. I probably reached perfection now, or at least completeness.

[Stefano]

I will do it probably tomorrow.

Well, I didn't. I have the famous (in Italy) "esame di maturità". Tomorrow evening will be my "notte prima degli esami" ("the night before the exams", there is even a song about this), so I will probably do it after the exam (without "s" this year, due to the Covid-19 pandemic).

[dabateman]

Good luck on your exams. Hope they pass through smoothly.

 

[Stefano]

Good luck on your exams. Hope they pass through smoothly.

Thank you David. Well, to pass I have to do at least 10/40 (I have 50/60 credit points, the sum must be at least 60/100), so I will almost surely pass (last famous words...). But anyway, thank you again.

[Stefano]

Could I not listen to it?

 

Tomorrow we will see. And then, I will dedicate more time to this forum (and other things). New LEDs on the way, new stuff will come.

[Stefano]

DONE✓

 

Not the healthiest look, but UV is known to make you ugly.

[Stefano]

And now... let's get back to the topic. I will put a table witl all water peaks, if no one thinks there is something to add/correct/remove, I think we can say this reference is complete. Finally.

[ulf]

Normally we focus on light here and you have extended into a part of the radio spectra.

 

If you want to go a bit further here is something about ELF in water:

https://en.wikipedia.org/wiki/Communication_with_submarines#:~:text=VLF%20radio%20waves%20(3%E2%80%9330,antenna%20on%20a%20long%20cable.

 

I became aware of this after visiting Grimeton, an ELF radio station designed completely without any electronic amplifier parts.

https://en.wikipedia.org/wiki/Grimeton_Radio_Station

[Andrea B.]

Editor's note about row colors: That table with color rows has lost its mind!! :devil:

I think that because it is a "nested" table has "nested" rows the BBCode bgcolor designations do not work properly. So it is probably best to revert to plain td tags as you used in the other tables. Quite a tedious edit, I know.

 

Did you see my suggestion elsewhere for formatting tables in an HTML tool and then making a JPG screen shot to post the table here on UVP? Also Excel spreadsheet tables can be saved as a JPG I think?

 

Almost any table formatting tool is better than this BBCode!

 

I'm not sure there is anything I can do to the BBCode definitions to fix things for nested rows/tables, but I will look at the definitions this evening when the day's other events are done. At the moment my cat is head butting me to come and feed her. So I will BRB to help you with the reformat.

 

 

I FOUND THE ERROR. One of your single quote marks was an apostrophe and not a single quote.

[Andrea B.]

I'm repairing it now.

[Stefano]

I FOUND THE ERROR. One of your single quote marks was an apostrophe and not a single quote.

Oh, really! That's the kind of error you may never notice while being literally in front of you. And HTML and BBCode don't forgive, they don't give warnings, either the code is correct or it won't work.

[Bill De Jager]

I FOUND THE ERROR. One of your single quote marks was an apostrophe and not a single quote.

 

Reminds me of the joys of debugging computer programs long ago when I was in grad school!

[Andrea B.]

Interestingly perhaps, I do not have a keyboard on this Macbook Pro which distinguishes between single quote and aphostrophe. They are the same symbol.

 

*****

 

Stefano, I repaired the quote and the colors. I tried an alternating light green and light yellow color scheme at the top of the table. At the bottom of the table I tried some wide alternating bands of color. If you think one of those color schemas helps in reading the data in the table, then it is easy enough to implement throughout the entire table. I used hex for the colors because the color words in BBCode are very limited.

 

*****

 

I'm still thinking that it is easier to format such data in an HTML app or in Excel and then make a screen shot or "save as" the document as a JPG. YMMV, of course.

[Stefano]

Thank you Andrea. I don't know why the table exits the page on the right side, but anyway... It can be fixed later. Still much better than before.

 

At this point, I want to ask the big question to everyone, since this reference could be useful to everyone at some point: there are currently three tables. They all contain the same data, the first two tables are exactly the same, I copied and pasted it to later convert it to another table with the transmission peaks instead (the tables now contain the absorption peaks). You can just ignore that and imagine there are two tables, the normal, white one, with λ, µ and α all in the same cell, and the colored one, in which λ, µ and α are written in individual cells. What is the best solution for you? Which table is the easiest for you to read? Andy Perrin and I discussed about this, and he preferred the first kind (white), because the second table (colored) had only black lines, and that made it difficult to read it for him. I personally like having each piece of data in a separate cell, but I also like the "compactness" of the first table. Maybe it would be better to color each "row stack" in the second table with a color, to distinguish the different peaks better. Or, as Andy suggested me, leaving it all white and making the lines "inside the peaks" lighter, while leaving those between the peaks black. What solution do you like the most? Let me know.

[Andrea B.]

off topic: If you turn off your bookmarks, then the page won't exit on the right??? I am not sure to what you are referring? Screenshot??

 

It might have been the nowraps I added. I removed them so the column widths are exactly like the preceding tables. Sorry bout that!!!

[Stefano]

From my smartphone:

The table is fine now, but the page (only this one) is rendered "skinny" (on the right there is a blue band). Everything is fine on my PC.

Maybe it is just a rendering error and not something to be too worried about.

 

Just tried this, with my smartphone in a horizontal position, the problem disappears.

 

Anyway, it may be my phone, nothing important.

[Andy Perrin]

It's a rendering error. Only happens when the window is too skinny.

[dabateman]

I like the first table structure better, keeping it together, because they are related.

I see the same skinnyness on my phone. The weblinks are long and may need the extra blue space.

 

[Andrea B.]

I thought I fixed it by removing the centering and nowraps on the third chart?

[Stefano]

Is this rendering error caused by the table or by the long links? Because if people prefer the white table over the colored one I will probably remove it. I don't want to make you waste your time on something not permanent.

[Stefano]

Or maybe you can copy and paste the table in your test topic, so that you could work on it. A fix would be helpful for everyone who wants to write a similar table. But I can leave it here on this topic if you prefer to work on it here. I don't have to remove it now.

 

Anyway, is there someone who prefers the colored table over the white one or everyone agrees with David and Andy? Just to be sure this is the best decision.

[Andy Perrin]

The rendering error is caused by the table being too wide for the device. There is no way to fit that big table on a skinny phone screen. I would just accept that it won't render properly on a phone. Put a note telling people to use a computer.

[Stefano]

The rendering error is caused by the table being too wide for the device. There is no way to fit that big table on a skinny phone screen. I would just accept that it won't render properly on a phone. Put a note telling people to use a computer.

If there is no way to fix it, it is useless to try to fix it. I will put a note as you said. Anyway, as I said, it isn't something too important, just a detail. What matters more is that all data is correct, the tables are easy to read, and the whole reference is well done.