Scientific Doubts about the "Welsbach Patent"


Senior Member.
There is a relatively recent article in the German Wikipedia about the theoretical base of the famous Welsbach patent which is often quoted by chemtrail believers.

The article's critique in a very small nutshell: Welsbach materials can't emit light without being considerably heated. They wouldn't be able to convert weak heat radiation to light, instead would act as a heat trap themselves.

No English version is available (yet), so I took a stab at translating the central paragraphs. Some - but not all - original links are included and 'translated' to their English equivalents. Additions in bracket by myself.

Original article (in German): Welsbach-Patent

Alleged principle

The name of the patent refers to the incandescent mantle which Carl Auer von Welsbach invented back in the 19th century [for gas lighting]. The basic idea of the patented method is that small particles with an emission spectrum similar to the material in this mantle are distributed by aircraft. In the visible range of light their emissivity is high, in the near-infrared area it's low and in far-infrared it's high again, as shown in the adjacent graph [see original article].

The inventors believed that such particles would be able to absorb the thermal radiation of the earth which contains mainly deep infrared, and then emit the gathered energy at least partially in the form of visible light.
Visible light does hardly interact with greenhouse gases, so the greenhouse effect would be reduced if the particles were able to absorb energy from far-infrared wavelengths and emit it in shorter wavelengths.

Doubts about the feasibility

According to Kirchhoff's law of radiation, a high emissivity is associated with a high degree of absorption, and vice versa. The particles with the proposed emission spectrum would therefore act like a greenhouse gas as they are expected to absorb the thermal radiation of the earth's surface. Entirely passive bodies without any source of energy and in local thermodynamic equilibrium with their environment cannot amplify individual wavelength ranges from the equilibrium radiation around them or move them to other wavelength ranges, because that would conflict with the Second Law of Thermodynamics.

Planck's radiation law provides an upper bound for the thermal radiation that a body with a given temperature can deliver in a specific wavelength range, when emitting electromagnetic waves solely because of its temperature. At temperatures occurring in the Earth's atmosphere, the maximum proportion of visible light which a purely thermal radiator can emit is negligible according to Planck's radiation law.

If the proposed particles could produce only a little more visible light than Planck's law permits, then this light could be converted to electric power by means of a photovoltaic system. Therefore useable energy would be gained from ambient heat, which would constitute a perpetual motion machine of the second kind. A realization of the invention, as described in the patent text, thus appears not to be physically possible.

Note: authorship of this Wikipedia article can be attributed to Mario Sedlak (diploma in Technical Mathematics from TU Vienna) who is interested in the contrail/chemtrail discussion. He has contributed an excellent round-up of the chemtrail conspiracy theory in the German skeptic's magazine "Skeptiker", issue 1/2016.
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Mick West

Staff member
The notion of "Welsbach materials" is almost unique to that patent (and the related conspiracy theories). I wrote this last year:

It's also interesting that the term "Welsbach Material" has never been used in the context of geoengineering outside of that one patent.

What are Welsbach materials? The patent says:
Which is interesting as the wording there suggests "the oxides of metal" are NOT "Welsbach materials".

In fact the term "Welsbach material" is almost exclusive to the chemtrail conspiracy theory. There's no wikipedia entery for Welsbach materials, the only real results are:

It seem that a "Welsbach material" is another name for material used for gas mantles (aka Welsbach mantles) - materials that glow brightly when heated.

So a "Welsbach material" is pretty much just Thorium Dioxide used on gas mantles.

With followup from @Marin B
I searched a patent database for the term "welsbach material", the first occurrence was in a patent that issued in 1930 for "Electric Lamp with Concentrated Light Source" - US Pat No 2,007,945. The term is used once in the following context: " A cylinder I2 of refractory material such as Nernst or Welsbach material may be supported by any suitable means..."

The term doesn't appear again until 1988 in a patent issued to Hughes Aircraft for "Selective Thermal Radiators"
Abstract:Source: US4755673A [EN] An improved thermal radiator uses host materials having high internal reflection and scattering co-efficients for improved effectiveness. Selective thermal radiators are used for frequency conversion of incident radiation through the Welsbach effect. A Welsbachmaterial screen is used to convert incident IR radiation into visible radiation, permitting visual observation of IR radiation and facilitating control and monitoring of IR equipment. Welsbach material is also used as a dynamic IR target which converts incident visible radiation into a high resolution IR source pattern. Welsbach material is also employed as a temperature stable material for converting solar radiation into heat.

Then it shows up in 4 more Hughes Aircraft publications around 1990, the last being a European patent publication for a "Temperature Regulating Coating". The term wasn't used for 20+ years after that until it showed up in US patent application publication no. 2014/0150668, for "Steel Rail Solar Radiation Sheilding (sic)", which published last year listing Keith Langenbeck and Shelton James as inventors.

So it shows up in just 7 patent publications, 5 of which were assigned to Hughes Aircraft.


Senior Member.
Interesting, but in my opinion it does not meet Wikipedia standards. Wikipedia articles must rely on reliable published sources. Original research is forbidden.


Senior Member.
Wikipedia articles must rely on reliable published sources.
There is this reference in the original article's footnotes:

Mario Sedlak: Physikalische Hindernisse bei der Umsetzung der im „Welsbach-Patent“ beschriebenen Idee In: Zeitschrift für Anomalistik. Bd. 15, 2015, ISSN 1617-4720, S. 317–325


Senior Member.
There is this reference in the original article's footnotes:

Mario Sedlak: Physikalische Hindernisse bei der Umsetzung der im „Welsbach-Patent“ beschriebenen Idee In: Zeitschrift für Anomalistik. Bd. 15, 2015, ISSN 1617-4720, S. 317–325
OK, but that's still the author of the Wikipedia article citing his own paper. He is not an expert in the field, and that journal is for paranormal studies, which I don't consider appropriate for this topic.


Senior Member.
OK, but that's still the author of the Wikipedia article citing his own paper.
I don't object there. However, it seems to be the case that the patent itself was not scrutinized by professional physicists so far.
My own modest knowledge does not allow me to evaluate the validity of the critique but I found it interesting enough to point it out. The same critique was embedded in the "Skeptiker" article I mentioned (in slightly different wording) but it is not available online so I referred to the Wikipedia version.

Mario Sedlak

New Member
Thanks for the feedback!

My Skeptiker article can be read online - however, without images and in german only. (The pictures on the page do not belong to my article.)

Also, I wrote a shorter article (in german too) where a professional atmosphere physicst confirmed that the idea of the Welsbach patent is nonsense.
To my knowledge, no professional scientist debunked the Welsbach patent so far, altough you need only textbooks to do so. I wish my contributions help to reach consensus in the community that the Welsbach patent describes a physically impossible invention.
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Mario Sedlak

New Member
Is that all he said? No detailed explanation?

The scientist Prof. Thomas Karl referred to Kirchhoff's law of thermal radiation which contradicts the basic idea of the Welsbach patent. The absorbed terrestrial radiation cannot be re-radiated by passive particles with a smaller wavelength. The so-called Welsbach particles would increase the greenhouse effect, he confirmed further.

The patent authors, of course, believed the opposite. However, they are completely wrong. It would be possible to construct a perpetuum mobile of the second kind if their idea could be realized as written in the patent text.
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