It is simply put, one of the best graphic representations of what’s really out there.
“There are more stars in our Universe than there are grains of sand on all the beaches on Earth.”
There are 100 to 400 billion stars in the Milky Way and more than 100 billion galaxies in the Universe – maybe as many as 500 billion. If you multiply stars by galaxies, at the low end, you get 10 billion billion stars, or 10 sextillion stars in the Universe–a 1 followed by 22 zeros. At the high end, it’s 200 sextillions.
The size of the universe is beyond comprehensible, and if one thing is true, then it’s that we have greatly underestimated everything about the universe.
The ‘limits’ of the Universe visible from Earth are at a staggering 46.5 billion light-years in all directions. That is, a diameter of 93 billion light-years. A light year is equal to 9.46 trillion kilometers. The calculation is huge, and yet, it is only the part of the Universe that we can see.
The universe encompasses everything known to us: matter, energy, space and time. The scales in the universe are so large that we cannot even imagine them.
Currently, it is impossible to know the exact size of the Universe. It could even be infinite, though it does not seem likely.
Not knowing what shape it has doesn’t help much since we cannot calculate its size either. In addition, it continues to expand. We only know the size of the Universe visible from Earth.
The truth is that everything related to the universe—consequently everything inside it— is a mystery.
If the Universe is only about 13.8 billion years old, how can there exist more distant objects in it? It is not possible that they have moved faster than the speed of light, right? The answer lies in the inflation of the Universe. In physical cosmology, cosmic inflation, cosmological inflation, or just inflation is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10−36 seconds after the conjectured Big Bang singularity to sometime between 10−33 and 10−32seconds after the singularity.
According to experts, inflation is the origin of everything: of space itself, of time, and of all physical laws, including the limit of the speed of light. Everything is created by inflation itself. So the inflation of the Universe is not subject to the limit of the speed of light. Inflation creates new space between objects and distances.
So far astronomers have used different models to determine the size of the cosmos. One model suggests that if the universe is expanding at the speed of light during inflation, its size should be 10 ^ 23 times larger than the visible universe.
There are other models that are based on the curvature of the universe to determine its size: if it is closed (as if it were a sphere), flat or open. In these last two cases, the universe should be infinite.
Now, what if there are several universes, and not just one? Mind-blowing!