Knowledge through high-precision measurements: the PTB
On 8 October 2013, the Physikalisch-Technische Bundesanstalt [PTB] in Germany was honoured as an EPS Historic Site. The ceremonial event took place at PTB’s Berlin Institute, where the precursor of PTB, the Physikalisch-Technische Reichsanstalt [PTR], was founded in 1887. The PTR was the first large national non-university research facility in Germany and the first metrology institute in the world.
Big names in physics and important scientific results characterised the first decades of the Physikalisch-Technische Reichsanstalt at the end of the 19th and at the start of the 20th centuries. The then Imperial Institute, whose founding fathers were Werner von Siemens and Hermann von Helmholtz, thus laid the experimental foundations of quantum mechanics with its precision measurements of the radiation of a black body. It was these measurements that led Max Planck to the principle of quantized energy. Many other fundamental physical laws and effects were discovered and “measured” at the PTR such as, for example, the Einstein-de-Haas effect and the Meißner-Ochsenfeld effect as a characteristic of superconductivity. Frequently used measuring instruments such as the Geiger-Müller counter were also developed at the PTR.
Even 126 years after its foundation, this metrological success story has not ended yet. Today, PTB ranks among the most renowned metrological institutes of the world and makes fundamental contributions whenever high-precision measurements are concerned. Currently, great scientific challenges are associated with the redefinitions of the physical base units in the International System of Units [SI] – experiments and measurements for the redefinition of the kilogram, the ampere or the kelvin. Generally, it is the objective to define all these physical units on the basis of fundamental constants such as, for example, Planck’s constant, the charge of an electron or the Boltzmann constant.
Against this scientific background, the ceremonial event with a great number of prominent guests from science, industry and politics took place in the lecture hall of PTB’s Berlin Institute. Welcoming speeches of the German Federal Ministries of Economics and Technology and for Education and Research were delivered by the two State Secretaries Ruth Anne Herkes and Cornelia Quennet-Thielen. The President of EPS, John Dudley, together with the President of the Deutsche Physikalische Gesellschaft, Johanna Stachel, awarded PTB the honour of being an EPS Historic Site and presented the Historic Site memorial plaque to the President of PTB, Joachim Ullrich.
The ceremonial event took on a scientific tone through two entertaining lectures: The Head of PTB’s Berlin Institute, Hans Koch, described PTR’s exciting early years when the true radiation formula for the “black body” – and with it quantum physics – was discovered. Wolfgang Ketterle of the Massachusetts Institute of Technology (Physics Nobel Prize 2001) and a member of PTB’s Kuratorium (Advisory Board) gave the commemorative speech. In this address on the subject of “Observing Quantum Matter near Absolute Zero Temperature”, Ketterle provided an insight into the phenomenon of Bose-Einstein condensation.
More information about EPS historic sites is on the EPS website.
