Jonny McAneney Wrote:

> It is around the 29 minute mark where he presents
> the chemical analysis of the fragments of "impact
> diamond" within the glass.
>
> They used a technique called Raman spectroscopy,
> which measures the rotational and vibrational
> modes of molecules to identify the structural
> fingerprint of the material, and found a raman
> shift peak at 1332 per cm (or reciprocal cm, or
> cm^-1 however you want to say it). This is the
> same raman shift as the diamond crystal structure
> (see here which is a screen grab from David's
> Youtube lecture).
>
> Now the issue I have with this graph is that there
> is no scale on the vertical axis, so one cannot
> know whether the scale is linear or logarithmic,
> which will affect the perceived width of the peak,
> and so could impact the next part of the analysis.

I have read too much of the ongoing discussion between
Comet Research Group (the proponents of the Younger
Dryas Impact Hypothesis) and their critics, e.g. C. Vance
Haynes, Vance T. Holliday, Tyrone L. Daulton, and
Nicholas Pinter, about whether or not nanodiamonds
occur in the Younger Dryas to conclude that the
identification of nanodiamonds is not an easy process.

The Raman spectra for lonsdaleite, the hexagonal
polytype of diamond, which has been reported from
impact structures, has a peak near 1,326 cm
and should have an additional peak near 1,175 cm
The 1332 cm peak is typical of diamonds unrelated
to extraterrestrial impact (Menneken et al. 2007)

It seems like a person needs something substantial more
than a few Youtube videos to make their point stick.

References

Menneken, M., Nemchin, A.A., Geisler, T., Pidgeon,
R.T. and Wilde, S.A., 2007. Hadean diamonds in
zircon from Jack Hills, Western Australia. Nature,
448(7156), p. 917-920.
[www.researchgate.net]
[www.researchgate.net]


Yours,

Paul H.

"The past is never dead. It's not even past."
William Faulkner, Act 1, Scene III, Requiem for a Nun (1951)



Edited 8 time(s). Last edit at 03/15/2018 10:33AM by Paul H..