22 July 2026 – Universitätsclub Bonn
Fifty years of VLBI at MPIfR – and why trust, not technology, is what makes the invisible visible.
“Something changed in February. Not everything. My time as Director at the Max Planck Institute for Radio Astronomy came to a close. Yet: My curiosity is still here. My sense of responsibility is still here. My collaborative spirit is still here. And the story continues…”
That is how I opened my closing remarks at Making the Invisible Visible, a symposium celebrating five decades of Very Long Baseline Interferometry at MPIfR: the science, the international collaborations, and the people who have made it possible. From the first VLBI measurements with the Effelsberg telescope to the Event Horizon Telescope images of M87* and Sgr A*, this has always been a story shared by many.
Looking back over fifty years, one conclusion stands out for me. Our telescopes deliver data, but trust is what turns those data into an image. VLBI only works when institutions on different continents, under different political systems and funding cultures, agree to observe on the same night, to share their recordings and to believe in one another’s calibration. Trust is the real instrument.
We met for an afternoon conceived as a salon: science, music and conversation in dialogue with one another. Jürgen Renn traced the arc from Einstein to the EHT image, from a single idea to the scale of collaboration that Big Science now requires. Antxon Alberdi, a companion of many years from Granada, looked back on five decades of VLBI at the institute, and Nadia Singer framed it all with Gershwin. Three early-career researchers, Debbrecht, Alexei Nikonov and Saurabh, spoke about their science, their aims and their concerns. They are the generation the work now belongs to, and their questions about careers and about open borders for science are the ones we must answer. A panel with Ken Kellermann, Agnieszka Słowikowska, Lutz Stenvers and David Hughes asked what international cooperation, the next generation and industry need from us now. The afternoon closed as it began, with the piano, followed by a reception in the foyer generously supported by MPIfR and NRAO.
That trust is under pressure today. Geopolitical tensions are reaching into laboratories, observatories and data networks. How we keep collaborating across those lines, without being naïve, is a question I want to work on in the years ahead.
This symposium was a thank-you to everyone who built that trust over fifty years. It is also where my next chapter begins.
Watch the Making the Invisible Visible: Symposium Finale– Nadia Singer’s music and my closing remarks.
Watch the entire Symposium: Making the Invisible Visible: Part 1 and Making the Invisible Visible: Part 2
View Photos from the symposium
See the symposium’s program.