Why Stars Are an Optical Illusion | Leonard Susskind

Описание: When we look up at the night sky, it feels like we are seeing the universe as it truly is — distant stars shining across vast stretches of space. The image feels immediate, direct, and real. But physics tells a very different story.

In this video, we explore why stars are an optical illusion.

This does not mean that stars do not exist. It means that what we see when we look at a star is not the star itself, but delayed and distorted information. Light takes time to travel, sometimes thousands or millions of years, before it reaches our eyes. What we observe is a message from the past, shaped by motion, gravity, and the structure of spacetime.

Drawing on ideas associated with Leonard Susskind, this video explains how stars are not objects we see “as they are,” but signals processed by the universe and reconstructed by our perception. Relativity, time delay, and gravitational effects mean that the position, state, and even existence of a star may no longer match what we observe.

In this sense, the night sky is not a live image of the universe. It is an archive. A collection of old information arriving at different times, from different reference frames, stitched together into something that feels like a single picture.

This perspective changes how we think about observation, reality, and existence itself. The universe is not presented to us directly. It is filtered through time, motion, and information.

This documentary-style video avoids equations and focuses on intuition, offering a clearer way to understand what it really means to “see” something in the universe — and why appearances can be profoundly misleading.