Help converting the NIST spectrogram of Calcium

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Discussion Overview

The discussion revolves around converting a spectrogram of Calcium from the NIST website into a sound wave or tone. Participants explore the theoretical and practical aspects of this conversion, including the interpretation of wavelengths and frequencies, and the challenges associated with producing audible sounds from high-frequency data.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses uncertainty about how to start interpreting the NIST spectrogram of Calcium and seeks guidance on converting it to sound.
  • Another participant suggests using the formula ##f = c / \lambda## to convert wavelengths to frequencies, noting that the resulting frequencies will be too high for sound and will require scaling down to the audible range.
  • Some participants propose treating the wavelengths as frequencies in Hz without further justification, raising questions about the validity of this approach.
  • A participant discusses the scientific justification for associating musical notes with Calcium, mentioning the reactivity of free Calcium and its presence in compounds like calcium hydroxyapatite and calcium carbide.
  • One participant provides a method for mapping frequency values from the NIST table to audible frequencies, suggesting a statistical approach to analyze the data, but questions the relevance of the resulting audio frequencies to Calcium.
  • Another participant references the Mosely plot of characteristic x-rays and discusses the potential for associating frequencies with atomic properties, emphasizing the need for a legitimate basis for such associations.

Areas of Agreement / Disagreement

Participants do not reach a consensus on how to effectively convert the spectrogram into sound or the validity of the proposed methods. Multiple competing views and uncertainties remain regarding the interpretation and application of the data.

Contextual Notes

Participants highlight limitations in defining the conversion process, the dependence on assumptions about the data, and the lack of a clear rationale for associating audio frequencies with Calcium properties.

Shea Thompson
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I am not a physics major and don't know even where to start trying to interpet this spectrogram from the NIST website of the element Calcium

https://physics.nist.gov/PhysRefData/Handbook/Tables/calciumtable2.htm

My goal is to find a way of converting this spectrogram into a tone or frequency equivalent of a soundwave

Any pointers or tips would be greatly appreciated!
 
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The wavelength given are in air, be we can neglect that and convert them to frequencies using ##f = c / \lambda##, where ##c \approx 3 \times 10^{18}## Å/s, so replacing the value of ##\lambda## by the one found in the table will give you the frequency ##f## in Hz.

The frequencies thus obtained will be way too high for sound, so you must decide by what factor to divide to put them in the audible range. You can then use the intensities given in the first column as relative amplitudes to build up a sound wave by superimposing, e.g., sine waves of the given frequency and amplitude.

I'm not convinced that the result will sound nice :frown:
 
On some level of generality - as you have not defined what you mean by "converting this spectrogram into a tone or frequency" - you can just treat wavelengths given as frequencies in Hz. Because why not?
 
It appears to me that you're seeking a scientific justification for associating a particular musical note with Calcium.

330px-Calcium_unter_Argon_Schutzgasatmosph%C3%A4re.jpg


The sample in the wikimedia image above is preserved in Argon -- free Calcium is not naturally available on Earth, because it's too reactive, so maybe you're thinking of the Calcium bound in bones and teeth as calcium hydroxyapatite (Ca10[PO4]6[OH]2), or in calcium carbide (CaC2), the anyhdride of acetylene gas.

If you're thinking more along the lines of resonant frequency, such as might be used in a metal detector, you'd have to know what mineral you were trying to find.

If you're looking at spectral lines for a possible basis, you have multiple lines available, as in your NIST table and in the following image (from https://en.wikipedia.org/wiki/Spectral_line):

375px-Calcium_spectrum_visible.png


If you want to try to start to map the chart's frequency values to audible frequencies, you could proceed something like as follows:

A wavelength of 22000 Å at the high end of your wavelength chart means the low end of the frequency band is 136270000 MHz. Moving the decimal point 12 places to the left gives a low-end audible tone of 136.27 Hz. The shorter end of the chart gives a frequency of 1364100000 MHz. Taking that down 12 decimal orders of magnitude results a high-end audible tone of 1364.10MHz. That preserves the ratio, and brings the frequencies down to audio levels. You then read and interpret the rest of the chart, and find some similarly preserving way to let the other data contribute to the audio realization.

So far there's no valid reason for asserting that this range of audio frequencies is more characteristic of Calcium than of some arbitrarily chosen other element.

Because frequencies are rates, the harmonic mean could provide some usefulness. The harmonic mean of the 2 frequencies is 247.27272727273Hz. That's within the realm of musically usable frequencies. So are the other 2 frequencies. You could do various statistical examinations, such as root-mean square-arithmetic mean-geometric mean-harmonic mean (RMS-AM-GM-HM) inequality. But you'd have to have a good reason, and I for one don't see a prima facie basis for a supposition that the NIST data on that table is going to produce anything you could use for your stated purpose. As far as I can tell, there's nothing in that table that can produce a consistent audio property to calcium property mapping.

Something that might actually offer some prospects in that regard, from a credible academic institution, that, like NIST, has due regard for doing real science: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/moseley.html

Taking a quick glance at the Mosely plot of characteristic x-rays, at Ca 20 you can drop the perpendiculars of the 4 points clustered at Calcium, in the mid-high 9 to just over 10 range.

moseley.gif


Using the Bohr model of the atom, the points on the plot represent very conspicuous spikes in the absorption or emission spectra at the outermost and next closer-in orbitals, and they plot a highly linear appearance that holds as we go up the elements increasing the atomic numbers in accordance with the periodic table.

xraych.gif


Mosely's theory is based on useful and plausible models, well-tested and verified principles, and backed up by good experimental data. His argument includes the tenet that elements can and at very high energies do exhibit frequency spectra that characterize them individually and that they can then be by a legitimate procedure associated with drastically lower frequencies that correspond linearly to their atomic numbers, and retain their characteristic individuation.
 

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