Question

Although the entire universe may be much larger than our observable universe, we can see only within our observable universe. The "boundary" of our observable universe is called ________?

1) Event Horizon
2) Cosmic Microwave Background
3) Hubble Sphere
4) Observable Horizon

Answer 1

The boundary of our observable universe is called the observable horizon, which limits the region from which light has had time to travel to us since the universe began.

Step-by-step explanation:

The "boundary" of our observable universe is known as the observable horizon, or more technically, the cosmic event horizon. This is the maximum distance from which light has had time to reach us since the beginning of the universe due to the finite speed of light. Anything beyond this horizon is beyond our view and cannot currently affect us within the limits of the standard model of cosmology. It's important not to confuse this with the event horizon of a black hole, which is the boundary beyond which nothing, not even light, can escape the gravitational pull of the black hole.

Measurements indicating the flatness of space suggest that the universe is at least 100 times larger than our observable horizon, potentially extending far beyond what we can see. The observable horizon encapsulates the entire region of the universe from which light has had sufficient time to reach us since the Big Bang, setting a limit to the observable universe.