Why the Universe May Not Be Infinite | Leonard Susskind

Описание: We are often told that the universe is infinite — that it extends forever in all directions.

But what does “infinite” really mean in physics?

In this video, we explore why the idea of an infinite universe may not be as straightforward as it sounds. Drawing on concepts associated with Leonard Susskind and modern cosmology, this documentary examines how geometry, relativity, and information theory reshape our understanding of cosmic size.

An infinite universe is a mathematical possibility. But physical infinity is something else entirely.

Einstein’s general relativity allows for universes that are finite yet unbounded — similar to the surface of a sphere. Such a universe has no edge, but it is not infinite in extent.

Modern cosmology also introduces horizons. There are regions of the universe we can never observe because light from them will never reach us. The observable universe is finite, even if the total universe may not be.

Even more radically, holographic ideas suggest that the amount of information contained within a region of space is proportional to its boundary area, not its volume. This hints at fundamental limits on information density.

Infinity may not be a physical property of reality. It may be an idealization we use in mathematics.

The universe may not have an edge.

But it may not be infinite either.