Sabine Hossenfelder

Sabine Karin Doris Hossenfelder is a German theoretical physicist, writer, science communicator, and online video creator. After working as an academic physicist for two decades, she achieved widespread public recognition in the early 2020s through her popular science content on YouTube. She is best known for her science communication work as well as her prominent critiques of theoretical physics research and academic practices.

Born in Frankfurt, Germany, Hossenfelder pursued her undergraduate studies in mathematics at Goethe University Frankfurt. She subsequently earned a doctorate in theoretical physics from the same institution in 2003. Her doctoral thesis, supervised by physicist Horst Stöcker, examined the production of microscopic black holes within theoretical frameworks featuring large extra dimensions.

Following her doctoral studies, Hossenfelder completed post-doctoral research appointments at several organizations, including the GSI Helmholtz Centre for Heavy Ion Research, the University of Arizona, the University of California, Santa Barbara, and Canada's Perimeter Institute. In 2009, she became an assistant professor at NORDITA in Stockholm. She moved to the Frankfurt Institute for Advanced Studies in 2015, where she led the Analog Systems for Gravity Duals research team. In 2023, she joined the LMU Munich Center for Mathematical Philosophy to research fine-tuning and locality in quantum physics foundations, a relationship that concluded in 2025. Her academic output includes papers on dark matter, quantum gravity, and black holes.

Alongside her academic work, Hossenfelder launched the popular-science blog Backreaction in 2006 and wrote articles for outlets like Nature, New Scientist, and Quanta Magazine. In 2018, she published her first popular science book, Lost in Math: How Beauty Leads Physics Astray, arguing that a focus on mathematical aesthetics has stymied progress in basic physics. She followed this in 2022 with Existential Physics: A Scientist's Guide to Life's Biggest Questions, which addressed themes including free will, consciousness, the Big Bang, simulation theory, and parallel universes.

During the COVID-19 pandemic in the early 2020s, Hossenfelder expanded her outreach into producing YouTube videos designed to make complex scientific ideas accessible. Her channel expanded quickly, passing one million subscribers by late 2023. By April 2024, she left full-time academic research to work as a full-time creator, reaching 1.72 million subscribers and 293 million total views by 2025.

Hossenfelder is widely known for her strong critiques of modern physics institutions, with her investigative and critical videos frequently drawing more views than her general educational videos. She has published opinion pieces in outlets such as The Guardian and The New York Times questioning particle physics research and collider experiments. While commentators have praised her ability to convey difficult topics clearly, critics argue her commentary exaggerates systemic issues, risks eroding public trust in scientific research, and encourages conspiratorial attitudes. Media commentators have labeled her approach contrarian or associated her content with conspiracy-focused science commentary.

In recognition of her academic and conceptual work, Hossenfelder received the inaugural Award for Innovative Thinking from the Frankfurt Institute for Advanced Studies in 2019.