When we look at the universe, we see only the part of it that is close enough to the light can reach us since the creation of the universe. The universe is estimated 14 billion years old, so at first glance you might think that we can not see what lies beyond 14 billion light-years away from us.
But this is not the case. The fact that the universe is expanding, so the heavenly bodies that we see, had to retire much further. In fact, the cosmic microwave background photons of electromagnetic radiation have gone the distance of 45 billion light-years, before getting to us. This means that the size of the visible universe is estimated 90 billion light years.
That’s a lot, but the universe is certainly a lot more. Many cosmologists wondered - how much more. Today we have the answer, thanks to a curious statistical analysis that produced Mihran Vardanyan and his colleagues at the University of Oxford.
Obviously, we can not directly measure the universe. So cosmologists have created different models that can calculate the size of the universe. For example, one model says that if the universe is expanding at the speed of light during the phase of inflation (inflation of the universe), then it should be 10 ^ 23 (1 with 23 zeros) times larger than the visible universe.
Other calculations based on numerical factors, such as the curvature of the universe, depending on whether it is closed like a sphere, flat or hyperbolic. In the latter two cases, the universe must be infinite.
If it is possible to calculate the curvature of the universe, it will determine the limits of its size.
The breakthrough that was achieved Vardanyan with colleagues, is that they have found simplest way of averaging a large array of information collected.
By applying the approach to various cosmological models of the universe, Vartanian and his colleagues managed to get the limit values for the size and curvature of the universe. These limit values were much more severe than other approaches.
They said that the curvature of the universe tends to 0. In other words, the most likely model looks flat universe. If the universe is flat, then it is endless, and their calculations confirm this. But even if it is not, then the universe is at least 250 times the volume of the Hubble (Hubble volume is approximately equal to the size of the observable universe.)