Curiosity Lecture 6: Seeing the Edge of The Universe

The Curiosity Lecture is an online lecture series by Abhiyan Labs, designed to ignite curiosity in young minds by exploring the fascinating world of scientific knowledge and discovery.

The lecture delivered by Prof. Subir Sarkar (Professor of Physics, University of Oxford, UK) delves into the fascinating world of cosmology and humanity’s evolving understanding of the universe. It begins by exploring historical perspectives on the nature of the universe, such as ancient Greek, medieval, and early modern cosmologies. These include ideas of a finite universe with boundaries and the later shift to the concept of an infinite universe, driven by thinkers like Copernicus and Kepler.

Prof Sarkar explains how early observations, such as those by Eratosthenes to measure Earth’s circumference and Aristarchus to calculate distances to the moon and sun, laid the groundwork for modern astronomical methods. Concepts like parallax, trigonometry, and light speed are introduced to describe how scientists determined celestial distances.

A significant part of the lecture addresses the Olbers’ Paradox, which questions why the night sky is dark if the universe is infinite and filled with stars. The speaker uses analogies, such as looking through a dense forest, to explain the limitations of visibility in an infinite expanse.

The lecture also emphasizes the development of observational tools, from early shadow-based measurements to advanced telescopes, and highlights how these innovations allowed scientists to explore beyond the visible spectrum. This progression helped refine our understanding of celestial objects, their movements, and the vast distances between them.

Overall, the lecture intertwines history, philosophy, and science to inspire curiosity about the universe and explain key astronomical concepts, while encouraging critical thinking about humanity’s place within the cosmos.

Watch the lecture: