APOD: The Cone Nebula from Hubble (2014 May 28)

[Chris Peterson]

I went to a technical school to be an electrician. We didn't bother with colors all that much, mostly just black, white and red, unless we were doing something with resistors.

The old carbon resistors, that were helpfully color coded with a variety of subtle variations on brown?

[neufer]

This caused the H-alpha to get bumped UP to green:

Bumped up in frequency. Bumped down in wavelength.
Maybe we should just settle for "bumped" with no modifying preposition at all.

• It's etymological:

<<The word infrared means below red. It comes from the Latin word infra (meaning below)
and the English word red. (Infrared light has a frequency below the frequency of red light.)>>

Well, we read a rainbow from top to bottom.

Which is why I'm "trying to be a cloud in someone's rainbow."

[Beyond]

I went to a technical school to be an electrician. We didn't bother with colors all that much, mostly just black, white and red, unless we were doing something with resistors.

The old carbon resistors, that were helpfully color coded with a variety of subtle variations on brown?

Black, white, brown, tan, gold, orange, blue yellow, green, violet, red, were some of the colors. As I remember, the body of the resistor was brown, so a different shade of brown was used when the brown value was called for. The guys in the electronics shop were way more used to them then us guys in the electrical shop.

[Chris Peterson]

It's etymological

Always dangerous grounds for assigning meaning or choosing words...

[neufer]

It's etymological

Always dangerous grounds for assigning meaning or choosing words...

Ground is generally the only thing below infrastructure.

[Ann]

Chris wrote:
We generally represent red at the top of the list (e.g. RGB) or the left in a spectrum.

I don't question the fact that red is usually mentioned at the top of the list. What really surprised me is that you said (or so I thought) that red is at the left in the spectrum. The way I think of it, blue is at the left in the spectrum - reflecting the short wavelengths of blue and violet light - and red is to the right in the spectrum.

Ann

[geckzilla]

I don't know which way it is presented more often. I've seen it presented both ways in many different places. Heck, if you do a search for electromagnetic spectrum and look at the pictures in the articles, it's very easy to find it represented left to right, right to left, up to down, and down to up often more than one way within the same article. In my own head I tend to think of red as being on top. I don't think there is any reason for this other than that it has always been on top in Photoshop. Obviously in a more formal setting I'd want to use more precise wording but, come on, it's Asterisk. Plus if I bug Art then I consider that an accomplishment.

[Nitpicker]

As this circa 1908 graphic intimates, the non-visible spectrum must go off into other dimensions:

Click to view full size image

http://upload.wikimedia.org/wikipedia/c ... l_1908.png

[neufer]

As this circa 1908 graphic intimates, the non-visible spectrum must go off into other dimensions:
http://upload.wikimedia.org/wikipedia/c ... l_1908.png

• ROY G BIV would never SCMP that way!

[Chris Peterson]

I don't question the fact that red is usually mentioned at the top of the list. What really surprised me is that you said (or so I thought) that red is at the left in the spectrum. The way I think of it, blue is at the left in the spectrum - reflecting the short wavelengths of blue and violet light - and red is to the right in the spectrum.

It is commonly shown both ways when parts of the spectrum outside the visible are included. When just the visible is discussed, I think it's far more common to place red on the left. That's probably related to the fact that nearly everybody learns the colors of the rainbow as a child, starting with red (even if your education was so neglected as to never learn about Roy G Biv).

How many people can smoothly recite the colors of the rainbow beginning with violet? Not many, I'd wager. And for those of us in cultures where we read from left to right, that also means we tend to envision lists as ordering left to right (if not top to bottom).

[neufer]

.
.

[url=http://www.ipac.caltech.edu/outreach/Edu/Herschel/backyard.html][size=200]Herschel Infrared Experiment[/size][/url]

---

<<Aristotle claimed there was a fundamental scale of seven basic colors. Originally Newton used only five colors, but later he added orange and indigo, in order to match the number of musical notes in the major scale.>>

[url=http://www.gootar.com/theory.htm]Major Chords are Primary Colors[/url]

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[Nitpicker]

Can't blame Herschel for the term "infrared" radiation (nor, I suspect, for that dreadful painting). Herschel called them "calorific rays".

(Neufer, what is "SCMP"?)

[BDanielMayfield]

Nuefer, after reading the link you provided to the "Herschel Infrared Experiment" I'm somewhat puzzled, because photon for photon, blue light is more energetic than red light. Photovoltaic devices work more effectively with light on the blue side of the spectrum than red light because of this. All who read these APOD discussions should know that blue stars are much hotter than red stars. Everyone whose ever learned how to use a welder's cutting torch knows that a blue flame is hotter than a red flame. So, when I saw that experiment with thermometers meassuring different parts of the spectrum that show hotter temps on the red side my skepticism was engaged. Are you trying to pull one over on us again, or what?

[BDanielMayfield]

And yet, we can feel the soothing warmth of infrared light, so the Herschel Infrared Experiment is no hoax or joke. So red is warm and blue looks cool but is actually, in a way, hotter. Infrared light warms our skin, but ultraviolet light, being more energetic, can burn our skin and even cause skin cancer. Red lights preserve night vision while blue light at night can be painfully blinding.

Sorry Ann, but I prefer red.

[Nitpicker]

Bruce, the difference is the concept of colour temperature, versus the wavelength of peak thermal emission at different temperatures.

See:
http://en.wikipedia.org/wiki/Color_temperature
versus:
http://en.wikipedia.org/wiki/Wien%27s_displacement_law

At the relatively low temperatures recorded by Herschel, the bulk of the heat was coming from infrared radiation.

[neufer]

Can't blame Herschel for the term "infrared" radiation (nor, I suspect, for that dreadful painting). Herschel called them "calorific rays".

(Neufer, what is "SCMP"?)

• Scarlet
  Crimson
  Magenta
  Purple

SC(a)MP, v. t. [SK(i)MP] To perform in a hasty,
neglectful, or imperfect manner; to do superficially.

• Herschel did not SC(a)MP the dreadful painting.

[Nitpicker]

My, what a strange dictionary you have.

[Beyond]

It's been Artfully designed.