and the known diameter is 43B lightyears, which is still mindbending

akira2501 · on July 13, 2023

Isn't that a radius, or more specifically, the distance from the earth to the edge of the observable universe?

hasmanean · on July 13, 2023

Isn’t that a dead giveaway? The universe expanded outwards at the speed of light from a central point…the radius is 21.5 billion lightyears and the diameter is 43B.

ianburrell · on July 13, 2023

I'm pretty sure the 43B is the radius. The diameter that we can see is 93B ly according to Wikipedia.

The universe is expanding which means we can see more than the age of the universe. The light from far away was carried long as the universe expanded which makes it look like traveled faster than light.