Fraunhofer lines on CD

Posted 19 July 2010 by

Photograph by Kari Tikannen. Photography contest, Honorable Mention.
Fraunhofer lines appear in sunlight reflected off a CD. The Fraunhofer lines are the dark absorption lines superimposed upon the colored spectrum.

15 Comments

Paul Burnett · 19 July 2010

Take a look at http://en.wikipedia.org/wiki/Fraunhofer_lines which explains what's pictured here.

For instance, the dark blue line in the pale blue section is probably the Iron absorption line.

bigjohn756 · 19 July 2010

How do I make a CD that will produce a uniform field of lines to show an accurate Fraunhofer spectrum.

Mike Elzinga · 19 July 2010

Ah; ROYGBIV (minus a bit) and not CMY. :-)

Old Ari · 19 July 2010

Richard of york gained battles in vain.

Wheels · 19 July 2010

If anyone wants to reproduce this kind of effect, there's a quick and easy way to make a spectrometer from a cardboard cereal box and a CD. Here are some examples of light sources and their spectra as seen by the CD spectrometer.

Gary Hurd · 19 July 2010

It got my vote

robert van bakel · 19 July 2010

Using Godwin's Law (of which, The Founding Mothers accused me of using in a previous post), I would like to say that these Fraunhofer Lines appear intelligently designed for the greater glory of the Reich: Heil Dembski!

Gary Hurd · 20 July 2010

I vote for this one. Hurah

fnxtr · 20 July 2010

bigjohn756 said: How do I make a CD that will produce a uniform field of lines to show an accurate Fraunhofer spectrum.
How about recording a single 80-minute long sine wave? Nice shot, Kari!

Alex · 21 July 2010

That's amazing! I would never have thought that the Fraunhofer lines would be visible in this way... but, of course! The Wikipedia article explanation is a good one.

Mike Dworetsky · 22 July 2010

Paul Burnett said: Take a look at http://en.wikipedia.org/wiki/Fraunhofer_lines which explains what's pictured here. For instance, the dark blue line in the pale blue section is probably the Iron absorption line.
More likely this is the hydrogen H-beta line, which is the strongest line in the pale blue region. The strongest green line is Mg I, the strong yellow line is the sodium D line (actually two close-together lines called D1 and D2)and the strong red line is H-alpha.

Mr.K.A.T. · 24 July 2010

In extreme red there could/should be dark O-ring due to oxygen in athmosphere, I think. It means that it should be more darker in late evening or early morning ..

Easiest way is go with DVD/CD into old dark barn where sun blinks through narrow slit of boards.

Mike Dworetsky · 24 July 2010

Mr.K.A.T. said: In extreme red there could/should be dark O-ring due to oxygen in athmosphere, I think. It means that it should be more darker in late evening or early morning .. Easiest way is go with DVD/CD into old dark barn where sun blinks through narrow slit of boards.
You are probably thinking of the atmospheric water vapour A and B bands, a bit redwards from H-alpha. I suspect the camera used to record the spectrum from the CD did not quite reach those wavelengths. However, I have seen at least one of them by eye at the extreme of deepest red (which sort of looks brown) in the solar spectrum. What do you do if you don't have a barn handy?

Mr.K.A.T. · 28 July 2010

|"What do you do if you don’t have a barn handy?"|

This:
http://www.student.oulu.fi/~ktikkane/CDSpektri.html

In 1.picture:
S=window, Venetian blind..
M=pocket mirror on floor
B=cardboard box where there is narrow slit.

colored contacts · 3 August 2010

Women’s are really fond of jewellery and they want it of the latest designs. They are always aware of the latest designs and the things which are in fashion. They can have knowledge about new designs from the internet also.