News Overview
Stay informed with our latest news and announcements on this page. For more in-depth content, we also encourage visitors to explore our bimonthly STRUCTURES Newsletter magazine, which features a variety of articles, interviews with members, and background information on our latest research and activities.
Research: Simulations of Planetesimal Formation Reproduce Key Properties of Asteroids, Comets
With simulations that resolve finer details than ever before, scientists Brooke Polak (Heidelberg University) and STRUCTURES member Hubert Klahr (MPIA, Heidelberg University) have modelled a key phase in the formation of planets in our solar system: the way that centimetre-size pebbles aggregate into so-called planetesimals tens to hundreds kilometres in size. The simulation reproduces the initial size distribution of planetesimals that can be checked against observations of present-day asteroids. It also predicts the prevalence of close binary planetesimals in our solar system.
Planet formation around a star proceeds in several stages. Initially, cosmic dust in the swirling protoplanetary disk around a new star clumps together due to electrostatic (van der Waals) forces, forming so-called pebbles a few centimetres in size. The pebbles in turn join together to form planetesimals: space rocks between tens and hundreds of kilometres in diameter. Finally, collisions among these planetesimals form even larger, gravitationally-bound, solid cosmic objects: planetary embryos, which can continue accreting planetesimals and pebbles until they become planets. Simulating this progression from centimetre-size pebbles to planetesimals, however, is challenging due to the disparate scales involved. The simulations by Polak and Klahr follow an innovative approach by using a kinetic description in which small groups of pebbles in a collapsing cloud in a protoplanetary disk are treated like a gas that can undergo certain phase transitions, and assigning a pressure to this “pebble gas.” In their new work, Polak and Klahr look at several versions of collapsing protoplanetary disk regions, each with at a different distance from the Sun, starting with a distance as close as Mercury's orbit and ending with a collapsing region as far away as Neptune.
Weblinks:
The first SIMPLAIX Workshop on “Machine Learning for Multiscale Molecular Modeling” will take place in the Studio Villa Bosch in Heidelberg on May 2-4, 2023. Please register to participate and to submit abstracts for contributed talks and posters by March 15 at the workshop's webpage. The workshop is organized by Rebecca Wade (HITS), Andreas Dreuw (IWR), Frauke Gräter (HITS), Fred Hamprecht (IWR), Ganna (Anya) Gryn’ova (HITS), Marcus Elstner (KIT), Pascal Friederich (KIT), Ullrich Köthe (IWR).
SIMPLAIX is a newly established cooperation between the Heidelberg Institute for Theoretical Studies (HITS), the Karlsruhe Institute of Technology (KIT) and Heidelberg University, focused on bridging scales from molecules to molecular materials by multiscale simulation and machine learning. The aim of the workshop is to bring together scientists working in the field to share their research and discuss current challenges.
More information:
SIMPLAIX Workshop 2023 - Heidelberg Institute for Theoretical Studies (HITS)
Click the image to open the poster as PDF.We are delighted to announce the launch of a new recurring series of talks and events on Scientific Machine Learning. The series kicks off on Thursday, January 19th 2023 from 16h30 to 18h00 at Mathematikon (INF 205, Conference Room, 5th floor). Machine Learning galore will feature lab presentations by PIs as well as scientific talks by junior scientists:
Machine Learning galore! - Programme:To help plan the catering, please register for free by clicking here.
- Lab presentations:
- Tilman Plehn, Rebecca Wade, Bernhard Höfle, Jakob Zech
- Science talks:
- Stefan Radev (Köthe lab): Modeling Uncertainty with Neural Networks
- Theo Heimel (Plehn lab): Normalizing Flows for LHC Physics
- Annika Reinke (Maier-Hein lab): Pitfalls and recommendations for image analysis validation
Scientific Machine Learning is a joint initiative from STRUCTURES and IWR aimed at fostering interactions within and development of the local machine learning community. Its portal, http://mlai.uni-heidelberg.de summarizes the many relevant events and news from across campus that would otherwise remain scattered across single institutions or fields.
The goals of this new platform align with the STRUCTURES Cluster of Excellence's objective of driving research into the fundamental understanding of current and future machine learning, and with IWR’s aim to leverage machine learning to enable the solution of long-standing problems in the natural and life sciences, the engineering sciences, as well as the humanities.
Further information and links:
- Scientific Machine Learning (MLAI) homepage
- Machine Learning Talks on Campus – Information service and mailing list
- Interdisciplinary Center for Scientific Computing (IWR)
In the new episode of Marsilius im Gespräch, the Podcast of Heidelberg's Marsilius Kolleg, Friederike Nüssel talks to Andreas Dreuw (Chemistry), Robert Scheichl (Mathematics, STRUCTURES Cluster) and Jan Schuhr (Law) about chances, limitations and risks of Artificial Intelligence (AI). During their time as Marsilius Fellows, the three scientists have been working on an interdisciplinary project Künstliche Intelligenz: Zwischen Wunderglaube und Wissenschaft.
The Marsilius Kolleg at Heidelberg University bridges the gap between sciences and humanities through meetings and joint projects, which in turn promotes understanding and cooperation between the sciences and the humanities. Founded in 2007, the Marsilius Kolleg is a central component of Heidelberg’s successful proposal granted by the Excellence Initiative, launched by the federal and state governments of Germany.
Weblinks:
Click the image for a larger view.A.I. or Artificial Intelligence – a technology that increasingly finds its way into our everyday lives. On one hand, it can make life easier in certain areas and complement human abilities, but A.I. can also cross boundaries. I AM A.I. – Artificial Intelligence Explained addresses questions surrounding A.I. and the novel traveling exhibition opened to the public for the first time ever in the Mathematics Informatics Station (MAINS) of the Heidelberg Laureate Forum Foundation. A wide array of interactive exhibits enable visitors to look at Artificial Intelligence from different angles and learn more about both its possibilities and limitations. Exciting experiments, videos and images show the mathematical methods behind the technology that vividly convey how A.I. works and where it is applied. Guided tours of the MAINS take place every Sunday at 2, 3 and 4 p.m. (in small groups). Registration is not required.
I AM A.I. was developed and implemented by IMAGINARY with funding from the Carl Zeiss Foundation and support by the Klaus Tschira Stiftung.
More information can be found at the MAINS' exhibition website.
Viruses have always fascinated physicists due to their apparent simplicity: a small genome protected by a shell of proteins and sometimes by an additional layer of lipids, highly optimized in regard to assembly, mechanical stability and information storage. This year's Bad Honnef Summer school, which will take place from September 10 - 15, 2023 at Physikzentrum Bad Honnef, Germany will provide a comprehensive view on biological viruses from the viewpoint of physics, bridging all the scales in from biomolecular structure through infection of single cells to virus spread in populations. The summer school is organized by Sarah Köster (Göttingen) and Ulrich Schwarz ( STRUCTURESHeidelberg) and targeted to advanced physics students, but also open to PhDs and Postdocs.
More information can be found at www.pbh.de.
Special Seminar by Pierre Haas on Cutting Through the Mechanics of Cell Sheet Folding, EMBL HD, Jan 20
On Friday, January 20 at 2 pm (CET), Pierre Haas from Dresden will be giving a talk on Cutting Through the Mechanics of Cell Sheet Folding as part of the Next Generation Seminar Series of Theory@EMBL at EMBL in Heidelberg:
Title: Cutting Through the Mechanics of Cell Sheet Folding
Abstract: The folding of cellular monolayers is a crucial step of multicellular development, including gastrulation, neurulation, and organogenesis, and is often driven by localized "large bending deformations" of apical constriction and cell wedging. The simplest process in which to study its mechanics is perhaps the inversion of the green alga Volvox, the spherical embryos of which turn themselves inside out through a programme of cell shape changes. In the first part of my talk, I will show how a theoretical model in which apical constriction and cell wedging appear as variations of the intrinsic curvatures of an elastic shell reproduces Volvox inversion quantitatively. I will highlight the novel mechanics resulting from these large bending deformations. In the second part of my talk, I will present recent laser ablation experiments revealing additional geometric incompatibilities between the local intrinsic curvature of the cell sheet and its global shape. I will discuss the mechanics of the resulting residual torques in the cell sheet and show how even small incompatibilities of this kind affect tissue folding. This suggests a more global picture of the mechanics of tissue folding, which does not therefore rely on localized apical constriction and cell wedging only, but also on other, more subtle cell shape changes in other parts of the tissue.
Time & place: Friday, January 20th 2023, EMBL Large Operon and via Zoom
Host: Virginie Uhlmann
If you would like to meet with the speaker (individually or in small groups), please sign up for a slot here (contact: Lizette Michele De Paula, EMBL.)
The STRUCTURES Project Management Office is happy to answer questions.