Prof. dr. ir. Bennie ten Haken

Lecture is given in Dutch

Dr. Emily Petroff

Astronomy in the blink of an eye: Searching for the fastest events in the Universe

Most things in the universe happen over millions or even billions of years but some things change on the timescales of human life and can be seen to change in a matter of months, days, or even seconds. These sources are called transients and are some of the most extreme events in the Universe, things like the collapse of a dying star, or a collision of two massive objects. Humans have been observing astronomical transients for centuries, from supernovae to gamma ray bursts, but recent advances in telescope power and technology mean we’re observing more and more transients each year and even finding new types such as the discovery of fast radio bursts in the past decade and the first observations of gravitational waves. This talk will focus on these elusive and ephemeral objects, how they are found, and where they are coming from.

Prof. dr. René van Roij

Iontronics: 21st-century physics from 19th-century equations

Quantum mechanics and relativity are of course true monuments of 20th-century physics, with fascinating open question and recent breakthroughs involving e.g. black holes, high-Tc superconductors, or gravitational wave detection. Solid-state electronics, which is deeply rooted in quantum mechanics, has long been another society-changing driving force developed during the 20th century. One could therefore easily think that all interesting developments in physics must revolve around these fields. Our own body, however, is still full of surprises and ill-understood phenomena, e.g. the working of the brain or the cause of cancer and dementia. At the same time the availability of clean and fresh drinking water is a huge societal problem in large parts of the world. Or how does an electric eel produce a potential difference that exceeds 600 V? Problems like these do not involve quantum mechanics or relativity: here ions (rather than electron and holes) move around in room-temperature liquids (rather than in solids close to absolute zero). In living organisms the ions are driven through membranes by ion pumps, and in artificial nanofluidic devices they are conducted through e.g. carbon nanotubes by electric fields, advected by osmotic flow, or spontaneously diffusing from high to low concentrations. The underlying equations for these physical phenomena all go back to the 19th century, e.g. the Laws of thermodynamics, the Poisson equation for electrostatics, the Navier-Stokes equation for fluid flow, and Fick’s law for diffusion. With modern computer-power, however, we can now actually solve these (coupled, nonlinear, partial differential) equations, even with new boundary conditions relevant on the nanometer scale. The nonlinear couplings give rise to new phenomenology, as we will see. The emerging field of iontronics involves, for instance, liquid cables (like our nerve cells), liquid diodes and transistors, artificial kidneys, blue-energy harvesters, and new proposals for desalination devices based on kidneys; iontronics therefore largely defies some traditional boundaries between physics, chemistry, biology, medicine, and engineering. In this talk we will discuss some recent developments in these areas.

Prof. dr. Paul van der Schoot

The Physics of Viruses: from Biology to Bionanotechnology and Materials Science

Abstract: Viruses are molecular machines that co-evolved with all forms of life, and reproduce by high jacking the biochemical machinery of living cells. This usually leads to the demise not only of the host cells but also of the organisms that these host cells are part of. Not surprisingly, viruses have a less than respectable reputation as purveyors of disease and death. Still, we may learn from viruses how to package genetic material, protect it from adverse environmental conditions and deliver it to susceptible cells, uncoat and take over control of their biochemical network. This would help us to perfect gene therapy, for instance. Scientifically, it is unclear why viruses are so stable, and why they self-assemble in solution into perfectly geometric structures although the proteins they consist of are not symmetric at all. In fact, exactly because viruses of a certain species are all the same shape and size, they also form perfect crystals, and, if elongated, liquid crystalline phases that can be used as scaffolds to take as starting point for the design of materials. In my presentation, I will highlight recent developments of the physics of viruses, and the rôle statistical mechanics takes in our understanding of virus structure and stability, and how this correlates with recent experimental observations.

Prof. dr. Huib de Swart

Lecture is given in Dutch

Dr. Fleur Zeldenrust

Lecture is given in Dutch