We know the universe is very big, but is it possible to make an estimate? First of all, we need to distinguish between the visible universe and the rest of the universe. The observable universe can be thought of as a kind of sphere with the Earth in the center. This sphere is expected to have a total diameter of 92 billion light-years, according to a new article on Space.com.
This means that the visible universe extends over 46 billion light-years on both sides of the Earth.
The concept of the visible universe
More than just physical boundaries, which actually don’t exist, we need to think of the visible universe, essentially, as everything we can observe or in any case hope to do.
The concept of the observable universe depends on the age of the universe and the speed of light, and therefore on the speed of information that can reach us. If the universe is about 13.8 billion years old, does this mean that we can observe up to 13.8 billion light years? In fact, this is not the case because in these 13.8 billion light-years the universe has continued to expand, much faster than the speed of light itself.
If the telescope observed something 13.8 billion light-years from Earth, given the constant expansion, that object, at the time of observation from Earth, would be 46 billion light-years away.
The universe does not expand uniformly
In fact, the estimates are more complex, Space.com explains. In fact, the universe does not appear to be uniformly expanding. As a study published in 2020, using data collected by ES XMM-Newton, NASA’s Chandra telescope and other telescopes, it appears that the universe is not expanding at the same speed in all directions.
Some galaxy clusters appear less bright than they would be if the rate of expansion was uniform. According to the astronomers who conducted the study, this means that these groups do not move at the same speed. Dark energy could play a role in this irregularity.
What is the size of the entire universe?
So how big is the universe really? It’s really hard to say because we can’t see the edge of the universe, not even visualize it because we’re not even sure what it looks like.
However, several teams of scientists have made estimates. Some of these have estimated that the entire universe, and thus also the invisible, could be really huge, much larger than the visible universe. We’re talking about six million light-years of expansion. According to some scientists, the difference in size between the observable universe and the overall universe, in terms of volume, can be similar to that between the atom and the observable universe.
Other estimates are more cautious. According to a team of researchers led by Mehran Vardanian of the University of Oxford, who conducted a statistical study using the Bayesian model, the overall universe should be at least 250 times larger than the visible universe. So it should have a span of about 7 trillion light-years.
“Internet trailblazer. Travelaholic. Passionate social media evangelist. Tv advocate.”