Old masters never used the green pigment copper resinate supposed to be present in their paintings. Dutch art historian Margriet van Eikema Hommes reached this conclusion on the basis of old paint recipes, investigations of paintings and experiments to reproduce the green paint. The scientist recently published her results in a richly-illustrated book.
Green copper-containing glazed paint on oil paintings by artists such as Frans Hals, Raphael and Titian was not made by dissolving the pigment verdigris - a green copper salt - in warm varnish to produce copper resinate. A careful study of dozens of previously ignored old paint recipes demonstrates that the paint was in fact made from finely-powdered verdigris mixed with a cold oil or vanish.
Van Eikema Hommes discovered that the copper resinate myth arose in about 1914. The chemist Laurie found two recipes for green paint in which verdigris was dissolved in warm varnish; a method which results in copper resinate. Laurie and many after him failed to see that these two recipes were intended for glass, furniture and metal foil and that there were dozens of other recipes for paintings on panels or canvas.
Dr Margriet van Eikema Hommes | alfa
Closing the carbon loop
08.12.2016 | University of Pittsburgh
Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences