I'd say it's a reasonable assumption though, given that all of the Universe which we actually do see, is in fact isotropic and homogeneous at the large scaleBill McKeeman said:I do not think we have any evidence of what an observer somewhere else in the Universe would see. You must be applying the Cosmological Principal, which is an assumption, not a fact.
Scientists use a variety of methods to measure the size of the Universe, including calculating the distance to objects using parallax, using the redshift of light to measure the expansion of the Universe, and observing the cosmic microwave background radiation.
The current estimated size of the observable Universe is about 93 billion light years in diameter. However, the actual size of the entire Universe may be much larger, as it is constantly expanding and may be infinite.
The current estimated age of the Universe is around 13.8 billion years. This age is determined by measuring the expansion rate of the Universe and extrapolating backwards to the point of the Big Bang.
Scientists determine the age of the Universe by measuring the cosmic microwave background radiation, which is leftover radiation from the Big Bang. By analyzing the temperature and patterns of this radiation, scientists can calculate the age of the Universe.
While scientists have made great strides in understanding the size and age of the Universe, it is currently impossible to determine the exact measurements. This is due to the vastness and complexity of the Universe, as well as the limitations of our current technology and understanding.