Showing posts with label future observable universe. Show all posts
Showing posts with label future observable universe. Show all posts

Friday, October 7, 2022

Facts about Future Visibility Limit

1. The future visibility limit is 62 billion light-years. This does NOT mean that objects at this distance emit photons toward us now, and that those photons will reach us sometime in the future.

2. Any object farther than 16.5 billion light-years emits photons toward us now, but those photons will never reach us, even if we wait for an infinite amount of time.

3. So what is 62 billion light-years? Well, it is the radius of a sphere from HERE NOW. Those objects within this sphere, whose photons we have not yet received, emitted light in the past when they were within 16.5 billion light-years of us. These photons are still on their way, and when they reach us in the future, we will be able to see those objects.

4. We will only be able to see objects in the future that are currently within the 62 billion light-years radius, and whose photons have already entered the 16.5 billion light-years radius.

5. We will never receive photons from these objects that haven't yet entered the 16.5 billion light-years radius. As a result, we will not be able to observe the view of these objects that those photons could have shown us.

6. Any galaxies currently forming within the 62 billion light-years radius and emitting their first photons now will never be visible to us if their distance is greater than 16.5 billion light-years.

7. We will not see these objects as they are now, nor as they will be in the future. We will see them as they were when they emitted the photons.

8.
There are no objects beyond 62 billion light-years whose emitted light is within the 16.5 billion light-years sphere. Any object farther than 62 billion light-years has never had its light reach us, not even in the past. These objects have never been visible to us, even at any point before Earth existed.