Why can't we see past the cosmological horizon?

The concept of the cosmological horizon refers to the limits of the observable universe. It marks the furthest distance from which light has had time to reach us since the Big Bang. The reason we cannot see past this horizon is that observing anything beyond it would require looking back in time to a period before the universe itself existed, which is impossible.

At distances beyond the cosmological horizon, the light emitted by objects would not yet have reached us since the universe has only existed for a finite amount of time. This limitation is inherently tied to the age of the universe and the finite speed of light. Any observations beyond this point would not correspond to any physical context that could still exist today, as we cannot receive light or signals from regions that have not been causally connected to us since the beginning of time.

In contrast, other options touch on relevant ideas, such as the non-existence of light beyond the horizon or the potential for observing objects that have ceased to exist, but they do not capture the fundamental reason linked to the causal structure of the universe and time itself.