The Earth is not the center of the universe. We are only the center of the visible universe. The Universe is most likely much bigger than a sphere with a radius of 13.7 billion light years. We don't even know if we're the only universe yet.
Also, event horizon refers to black holes and not universes.
Scientists tell us that the distance from the Hubble telescope to the event horizon (edge of the Universe) is 13.73 billion light years. In all directions. They also tell us the Universe is 13.7 billion years old. So the earth is in the center of the Universe.
If the radius is 13.7 billion L.Y. then the diameter is about 28 billion L.Y. and the circumference is about 84 billion L.Y. The Universe has an equator and poles. The Universe rotated 50 times sence the expansion.
The expansion began within the vicinity of Earth. The Universe is icotropic, which means there are the same amount of galaxy's all around us. Top, bottom, left, right, forward, backward, the same amount galaxy's and radiation.
The Earth is .0001% in the sweet spot or goldilocks zone of the Universe. We are in a 35 galaxy cluster which is in the goldilocks zone of a mega cluster. Our galaxy is in the goldilocks zone of the cluster we are in. Our solor system is in a goldilocks zone from the center of our galaxy's black hole that powers our galaxy 25000 light years away. The Earth is in a goldilocks zone from our Sun. The surface of the Earth is a goldilocks zone between our atmosphere and the core of the Earth. And you in front of your fireplace out in the wilderness.
We receive different kinds of radiation and gas from the stars and of super novas that are necessary for life. Not too many , not too few, just the right amount of super novas must occur and the gas's mix to proper proportions before entering the Earth's amosphere. The Earth does not manufacture these things and our only source are those stars.