Bharat Ratra's Lecture in the Municipal Library

A public lecture titled The Mystery of Dark Energy: Why Is the Universe Still Accelerating? was held on 15 May at the Municipal Library in Prague. The talk was delivered by Professor Bharat Ratra of Kansas State University, recipient of the 2025 Julius Edgar Lilienfeld Prize of the American Physical Society. The event opened with remarks from Luke Meinzen, cultural attaché at the US Embassy, who together with Dr. Ignacy Wolak-Sawicki welcomed Professor Ratra to the venue.

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In his lecture, Professor Ratra outlined the modern standard model of cosmology, beginning with rapid inflation after the Big Bang and tracing the development of structure in the universe. The talk addressed unresolved questions, including the mismatch in current measurements of the expansion rate, and noted that future telescopes such as the James Webb Space Telescope may provide further data. The presentation also covered the scales of the universe and the limits of Earth‑based intuition, explaining the roles of dark matter and dark energy in shaping present‑day cosmological models.