The following slide has been part of Richard Gage's 9/11 Truth presentation for several years, at least since 2008 when it showed up in a version of 9/11: Blueprint for Truth video (which is basically Gage giving the extended version of his slideshow).
It's supposedly the spectrum of a sample of slag taken from a cut steel beam that's currently in the International Peace Garden on the US/Canadian border.
He says this is the chemical signature of thermite. He also claims that the irregular and messy nature of the cut on the beam shows it was not Oxy-acetylene, contrasting it with a "clean" cut on a different beam.
Here's a closer look.
Gage said, in a recent podcast,
In order to better understand what the X-EDS spectrum actually meant, I did a bit of reading.
While looking as some X-EDS results on Google Images, I happened to notice one that looked familiar:
Fe is iron, Mn is Manganese, Si is Silicon, Al is Aluminum. Notice Gage said the important parts of the signature were Mn, Al, and Fe. Let's compare those peaks with this sample of carbon steel rust. I've scaled it vertically to match the background levels.
It's a perfect match for those elements! The only different is that the large peak on the right is labeled "Fe" on the rust particle, but Fe Mn on the slag. Yet the peak itself is nearly identical. Then I remembered what it said in Wikipedia:
Manganese and Iron have overlapping peaks! Specifically the K-beta line for manganese overlaps the K-alpha line for iron. Most elements have two measurable lines on the spectrum, alpha and beta. The alpha line is the stronger line. This large combined peak is the K-alpha of iron (6.402) and the K-beta of Manganese (6.490) . This means that the amount that Mn contributes to that Fe/Mn peak is less than the tiny K-alpha Mn (5.897) peak to the left of it.
How much less? Look at an X-EDS spectrum of manganese without iron:
Mn K-beta about 1/8th the size of Mn K-alpha. Meaning there's basically no Mn in that second peak in the slag chart.
Which means the "signature" of Mn, Al, and Fe from the slag sample matches the carbon steel rust sample exactly.
Which means it's not thermite residue.
It's slag for the column being cut after the collapse, possibly with a thermal lance which explains the irregular cut (which isn't even that irregular without the forced perspective in that photo.
But what about the other elements mentioned on the slide?
S is sulfur, K is potassium Ca is calcium. Let's look at those, keep in mind the alpha and beta peaks.
The sulfur peak is barely there, it's actually less in the slag sample than in the rust sample. The Potassium (k) K-alpha peak is similar, and the even smaller K-beta peak is obscured by the Calcium K-alpha peak. They totally misrepresented this analysis.
Of course this proves nothing about the collapses of the towers other than that particular column was not cut with thermite. It does however prove that Architects and Engineers for 9/11 Truth don't really understand X-EDS spectra analysis. They have used this faulty interpretation to make a false claim over and over for ten years.
If they can get something as simple as this wrong, then we should probably assume they've got quite a few other things wrong too.