Press releases

The topic of electricity often poses difficulties for many secondary school students in physics lessons. Physics Education Researchers at the Goethe University and the University of Tübingen have developed and empirically evaluated a new, intuitive curriculum as part of a major comparative study. The result: not only do secondary school students gain a better conceptual understanding of electric circuits, but teachers also perceive the curriculum as a significant improvement in their teaching.

FRANKFURT / TÜBINGEN. Life without electricity is something that is no longer imaginable. Whether it be a smartphone, hair-dryer or a ceiling lamp – the technical accomplishments we hold dear all require electricity. Although every child at school learns that electricity can only flow in a closed electric circuit, what is actually the difference between current and voltage? Why is a plug socket a potential death-trap but a simple battery is not? And why does a lamp connected to a power strip not become dimmer when a second lamp is plugged in?

Research into physics education has revealed that even after the tenth grade many secondary school students are not capable of answering such fundamental questions about simple electric circuits despite their teachers' best efforts. Against this backdrop, Jan-Philipp Burde, who recently became a junior professor at the University of Tübingen, in the framework of his doctoral thesis supervised by Prof. Thomas Wilhelm at Goethe University, developed an innovative curriculum for simple electric circuits, which specifically builds upon the everyday experiences of the students. In contrast to the approaches taken to date, from the very outset the new curriculum aims to help students develop an intuitive understanding of voltage. In analogy to air pressure differences that cause an air stream (e.g. at an inflated air mattress), voltage is introduced as an “electric pressure difference" that causes an electric current. A comparative study with 790 school pupils at secondary schools in Frankfurt showed that the new curriculum led to a significantly improved understanding of electric circuits compared to traditional physics tuition. Moreover, the participating teachers also stated that using the new curriculum fundamentally improved their teaching.

The two researchers from Frankfurt and Tübingen have now published a detailed description of the theoretical considerations underlying the teaching concept in the renowned international journal “Physical Review Physics Education Research" in the framework of the “Focused Collection: Theory into Design". The German Society for Chemistry and Physics Education (GDCP) awarded its “GDCP-Nachwuchspreis", a prize presented each year for the best dissertation or post-doctoral thesis in chemistry and physics education in the German-speaking region, to Burde for his dissertation. As of the winter semester 2019/20 Burde was appointed to a junior professorship for Physics Education Research supported by the Vector Foundation at the University of Tübingen. On the basis of his work a cross-border consortium encompassing the Universities Tübingen, Frankfurt, Darmstadt, Dresden, Graz and Vienna has been constituted with the objective of making the subject of “simple electric circuits" more interesting and more comprehensible by embedding the topic in contexts from daily life.

Publications:
Jan-Philipp Burde and Thomas Wilhelm (2020). Teaching electric circuits with a focus on potential differences. In: Phys. Rev. Phys. Educ. Res. 16, 020153, DOI: https://doi.org/10.1103/PhysRevPhysEducRes.16.020153

Jan-Philipp Burde (2018): Konzeption und Evaluation eines Unterrichtskonzepts zu einfachen Stromkreisen auf Basis des Elektronengasmodells. Studien zum Physik- und Chemielernen, Band 259, Logos-Verlag, Berlin, ISBN: 978-3-8325-4726-4, http://doi.org/10.30819/4726

Picture download:
http://www.uni-frankfurt.de/95652319
Caption: Jun.-Prof. Dr. Jan-Philipp Burde, University of Tübingen. Photo: Friedhelm Albrecht for University of Tübingen

http://www.uni-frankfurt.de/95652342
Caption: Prof. Dr. Thomas Wilhelm, Goethe University Frankfurt. Photo: Felix Richter

Further Information:
Prof. Dr. Thomas Wilhelm
Executive Director
Department of Physics Education Research
Goethe University Frankfurt
Phone: +49 69 798-47845
wilhelm@physik.uni-frankfurt.de

Jun.-Prof. Dr. Jan-Philipp Burde
Physics Education Research Group
University of Tübingen
Phone: +49 7071 29 78651
jan-philipp.burde@uni-tuebingen.de

On 22 January, the Indian writer Arundhati Roy will be the featured guest speaker in the renowned "In Transit|ion" lecture series at Goethe University Frankfurt. The series is an international and transdisciplinary programme offered by the Institute of English and American Studies at Goethe University Frankfurt. In the Zoom event:

"The syntax of everyday injustice" on 22.01.2021
10:00h - 12:00h CET (Central European Time)
14:30h - 16:30h IST (India Standard Time)

Roy will read from her new work, forms the basis for the subsequent discussion, moderated by Dr. Pavan Malreddy, research associate at the Institute of English and American Studies. The event will be held in English. 

Arundhati Roy is the author of the award-winning bestseller "The God of Small Things," published in 1997, in which she writes of the connections between the caste system, class society, capitalism and imperialism. In the years between the publication of her first and second critically acclaimed novel, which appeared two decades later, she mainly wrote literary and political essays and confronted Indian society on a variety of topics: religious persecution, economic inequalities, caste and class hierarchies, the exploitation of natural resources and the resulting expropriation of small farmers in the name of development.

Her extensive non-fiction work including "The Politics of Power," and "From the Workshop of Democracy," and her second novel "The Ministry of Extreme Happiness" explain how capitalism and privatisation undermine democracy, destroy the environment and irreversibly accelerate climate change. Both her novels and her non-fiction work are the subject of lively, sometimes heated, scientific debates both inside and outside India. Her works are read today in more than forty languages.

Roy is an outspoken critic of communalism and majoritarianism in Indian politics. Her concise analysis of grassroots fascism and the ideological breeding ground it needs to flourish in Indian society and elsewhere forms the basis of her most recent work "Azadi - Freedom, Fascism, Fiction" (2020).

The lecture series "In Transit|ion - Frankfurt Lectures in Literary and Cultural Studies" is an international and transdisciplinary series organised by the Institute of English and American Studies at Goethe University Frankfurt. Twice a semester, leading writers and scholars from the English-speaking world present their work in the fields of American Studies, English Studies and Anglophone Literatures and Cultures. Since its inception in 2016, the series has featured speakers from top international universities in Great Britain (Oxford, Cambridge), the U.S. (Columbia, Chicago), Australia (Monash University) and India (North Bengal).

Please register for the event by e-mail: pavanmalreddy@protonmail.com

Further information:
Dr. Pavan Malreddy, New English Literatures and Cultures (NELK) &
Frankfurt Memory Studies Platform (FMSP)
Goethe University Frankfurt am Main.
malreddy@em.uni-frankfurt.de; https://www.uni-frankfurt.de/72041247/In_Transition

Extremely dense neutron stars may contain unstable hyperons in their interior, which, like the stable hadrons of the atomic nucleus, protons and neutrons, are held together by the strong interaction. Scientists from the ALICE collaboration at the accelerator centre CERN have now developed a method to precisely measure the strong interaction between unstable hadrons in experiments for the first time. Research teams from Goethe University headed by Professor Harald Appelshäuser and TU Munich headed by Professor Laura Fabbietti were involved in the development.

FRANKFURT. In an article published today in Nature, the ALICE collaboration describes a novel method that will allow precision measurements of the strong interaction between hadrons at the Large Hadron Collider (LHC) accelerator at CERN in Geneva.

Hadrons - which include protons and neutrons - are particles composed of two or three quarks, which are held together by the strong interaction. However, the interaction is not limited to the interior of the hadron, but extends beyond it. It leads to something known as residual interaction, due to which hadrons also exert forces on each other. The best-known example is the force between protons and neutrons, which is responsible for the cohesion of atomic nuclei. One of the great challenges of modern nuclear physics is to achieve an accurate calculation of the strong force between hadrons, which is based on the underlying strong interaction of quarks.

Within the framework of something known as "lattice QCD" calculations, the effective strong force between hadrons can be calculated on the basis of the fundamental theory of the strong interaction between quarks. However, these calculations are only very accurate for hadrons containing heavy quarks. This applies, for example, to hyperons, i.e. hadrons that contain one or more strange quarks. Although the strong interaction caused by collisions of hadrons can be studied in scattering experiments, it is difficult to perform these experiments with unstable hadrons such as hyperons. Accordingly, an experimental comparison with the precise theoretical predictions from the lattice QCD for hyperons is difficult.

In today's publication of the ALICE collaboration a method is presented which allows the study of the dynamics of the strong interaction for arbitrary pairs of hadrons. This concerns especially those hadrons which are short-lived, i.e. which decay after fractions of seconds and therefore cannot be investigated in scattering experiments. Instead, the hadrons are generated in proton-proton collisions at the LHC. The interaction between them can be measured on the basis of their relative momentum distribution.

Professor Laura Fabbietti from the TU Munich, who has contributed significantly to the results presented here, emphasises that this breakthrough is due to both the LHC and the ALICE detector. The LHC is able to generate a very large number of hadrons with strange quarks and thus provides an insight into the nature of the strong interaction. The ALICE detector and its high-resolution Time Projection Chamber (TPC), in turn, would provide the necessary precision to identify the particles accurately and measure their momentum accurately.

Harald Appelshäuser, professor at Goethe University, has been leading the ALICE TPC project for ten years and is co-author of the publication. He works closely with Laura Fabbietti's Munich group and emphasises that the method presented would usher in "a new era of precision studies of the strong interaction between exotic hadrons at the LHC."

The method presented is called femtoscopy because the processes examined take place in a spatial area of about 1 femtometre (10-15metres). This corresponds approximately to the size of a hadron and the range of the strong interaction. Using this method, the ALICE collaboration has already been able to study interactions between hyperons containing one or two strange quarks. In today's publication, a measurement of the interaction between a proton and the omega (Ω) hyperon has now been investigated for the first time and with high precision. The omega is the rarest of all hyperons and consists of three strange quarks.

Professor Appelshäuser emphasises that the significance of the results goes beyond the verification of theoretical calculations: "Femtoscopic investigations can significantly expand our understanding of very dense stellar objects such as neutron stars, which can contain hyperons in their interior and whose interaction is still largely unknown."

Publication: Shreyasi Acharya et al. (ALICE Collaboration): Unveiling the strong interaction among hadrons at the LHC. Nature, 9. December 2020 – https://doi.org/10.1038/s41586-020-3001-6

Explanatory video by TU Munich on this subject:
Rätselhafte Neutronensterne – Präzise Messung der starken Wechselwirkung - YouTube

Images may be downloaded here:
https://cds.cern.ch/record/2653650/#4

Caption: In the future, hyperons will be measured at the ALICE detector of the CERN particle accelerator centre. Scientists from Goethe University are part of the ALICE collaboration. Credit: CERN

Further information
Prof. Dr. Harald Appelshäuser
Institute for Nuclear Physics
Goethe University Frankfurt
Phone: +49 69 798-47034 or 47023
appels@ikf.uni-frankfurt.de

On Saturday evening (5.12.2020), a container containing a sample of the asteroid that had been dropped by the Hayabusa 2 space probe landed in the Australian desert. The chemical "fingerprint" of the water from the asteroid Ryugu could prove that the water on Earth actually originated from asteroid impacts in the early history of the Earth. Up to now, asteroids could only be examined after fragments impacted onto the Earth and therefore contamination by the Earth's water could not be ruled out. In the coming year, the material sample will be examined by scientists all over the world, including a scientific team from Goethe University.

FRANKFURT. When it was formed, the young proto-Earth was hot and probably circled around the sun in a very dry zone where water evaporated and was blown into space by the solar wind. According to one theory, our blue planet came to its great oceans through watery celestial bodies that hit the earth. As spectral analyses of comet tails have shown, it was most likely not comets.

This is because in their ice, the ratio of hydrogen with two protons in its nucleus, deuterium (D), to hydrogen with one proton in its nucleus (H) is usually different from that on Earth. On the other hand, the water trapped in certain meteorites - i.e. in fragments of asteroids that have hit the Earth - is almost exactly the same as terrestrial water. Such C-class asteroids are highly carbonaceous and come from the outer part of the asteroid belt that orbits the sun between Mars and Jupiter. Ryugu is one of them.

Prof. Frank Brenker, geoscientist at Goethe University, will examine the Ryugu sample together with his colleague Dr. Beverly Tkalcec. He explains: "There are very good scientific arguments that the D/H ratio we find in meteorites is indeed similar to that of asteroids in space. Nevertheless, we cannot rule out water vapour contamination on Earth: after all, 90 percent of an asteroid evaporates when it passes through the atmosphere, and even if it hits a dry desert, the meteorite can absorb water until it is found, for example from early morning fog. With the Ryugu sample we will finally get certainty on this issue".

To this end, from the middle of next year, the Frankfurt researchers will examine and screen Ryugu samples for their chemical composition at the particle accelerators ESRF in Grenoble and DESY in Hamburg. Later in the year, Ryugu samples will be cut with the help of a focused ion beam and will be examined with a transmission electron microscope at Goethe University. Tkalcec and Brenker want to determine the exact geological history of the asteroid. In order to be able to assess the measured values for the water, but also the organic compounds that occur, it is immensely important to understand all the processes that led to their formation in the first place. The temperature achieved by the asteroid is just as important here as the circumstances of the formation of water-containing minerals, and the influence of impacts on the surface of the asteroid.

The building blocks for life on Earth may also come from carbon-rich asteroids such as Ryugu, since sugars and components of proteins (amino acids) and the hereditary molecule DNA (nucleobases), which could have been formed from inorganic substances under suitable conditions, have already been found in meteorites. For this reason as well, numerous scientific teams from all over the world will be working on the analysis of the Ryugu samples.

Images for download:

1. Prof. Dr. Frank Brenker, Institute für Geosciences, Goethe University Frankfurt. Credit: Jürgen Lecher for Goethe University. http://www.uni-frankfurt.de/95132289
   
   
2. Prof. Dr. Frank Brenker, Institute für Geosciences, Goethe University Frankfurt. Credit: personal photo. http://www.uni-frankfurt.de/95132407
   
   
3. Dr. Beverley Tkalcec, Institute für Geosciences, Goethe University Frankfurt. Credit: personal photo. http://www.uni-frankfurt.de/95132444
   
   
4. Landing of space probe Hayabusa 2 on the asteroid Ryugu for the collection of samples. Illustration: Akihiro Ikeshita für JAXA. https://www.hayabusa2.jaxa.jp/en/galleries/cg/pages/touchdown1.html
   
   
5. The asteroid Ryugu from a distance of 20 kilometres, photographed by the probe Hayabusa 2. Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu and AIST. 
   https://www.hayabusa2.jaxa.jp/en/galleries/ryugu/pages/fig11_fmhome_front.html
   
   
6. Hayabusa 2 passes by Earth: On its return, the probe flew past Earth on its way to another mission and sent a capsule containing the Ryugu sample to Earth. The capsule landed in the Australian desert on Saturday, 5 December 2020. Illustration: Akihiro Ikeshita for JAXA. 
   https://www.hayabusa2.jaxa.jp/en/galleries/cg/pages/swingby.html

Further information
Prof. Dr. Frank Brenker
Institute for Geosciences – Nanoscience
Phone: +49 151 68109472
f.brenker@em.uni-frankfurt

An ischemic stroke is an extreme disturbance of the homeostasis of brain and body. Among other things, the immune system triggers an inflammatory reaction that can either overshoot or turn into an immune deficiency. For the first time, an international team of researchers – among them scientists from Goethe University Frankfurt, Germany – has now shown that tRNA fragments play a role in this immune reaction. Fragments of tRNAs, which transport amino acids during protein synthesis (“transfer RNA"), were long merely considered cellular waste. The aim of the research is to find new target structures for therapeutics.

FRANKFURT. Sebastian Lobentanzer of Goethe University, Frankfurt, has been studying small RNA dynamics in various contexts using bioinformatic methods. Recently, small RNAs have become more and more interesting for researchers, primarily because of their extensive regulatory functions. To examine these functions in stroke, Lobentanzer joined Katarzyna Winek of Hebrew University, Jerusalem, to study microRNAs and tRNA fragments in blood samples from ischemic stroke patients collected at Charité, Berlin. “tRNA fragments, which until now were only thought to be debris of the amino acid-transporting tRNAs, have recently been shown to possess biological functions; naturally, we were very interested in that," explains the pharmacologist.

The project was initiated and led by Hermona Soreq (Hebrew University, Jerusalem, Israel) and Andreas Meisel (Charité, Berlin), who jointly study the contributions of small RNA regulators of cholinergic signaling in blood cells of stroke patients, funded by the Einstein Foundation. Katarzyna Winek from The Edmond and Lily Safra Center of Brain Science at The Hebrew University collaborated with Sebastian Lobentanzer at the Institute for Pharmacology and Clinical Pharmacy (AK Jochen Klein) at Goethe University Frankfurt, Germany.

This collaborative effort was able to show, for the first time, the involvement of monocytic tRNA fragments in the poststroke immune response. "Simply put, there may be a 'changing of the guards,' in which tRNA fragments replace microRNAs in monocytes," explains Lobentanzer. “Bioinformatic network analyses show that these two small RNA species have vastly different functional roles in the immune response, and thus may work in synergy in the regulation of homeostasis." In the long run, the researchers want to find therapeutics to modify these processes. Indeed, if the immune status of each patient after a stroke could be individually determined, many complications could be avoided.


Publication: Katarzyna Winek, Sebastian Lobentanzer, Bettina Nadorp, Serafima Dubnov, Claudia Dames, Sandra Jagdmann, Gilli Moshitzky, Benjamin Hotter, Christian Meisel, David S Greenberg, Sagiv Shifman, Jochen Klein, Shani Shenhar-Tsarfaty, Andreas Meisel, Hermona Soreq: Transfer RNA fragments replace microRNA regulators of the cholinergic post-stroke immune blockade. PNAS https://doi.org/10.1073/pnas.2013542117

Further Information:
Dr. Sebastian Lobentanzer,
Institute for Pharmacology and Clinical Pharmacy
Goethe-Universität Frankfurt
Tel.: +49 69 798-29370
lobentanzer@em.uni-frankfurt.de