The Milky Way, our galaxy, together with all its companions, is at the very edge of a huge void of more than a billion light-years of extension and inside which there is "nothing". That is the extraordinary conclusion presented by a group of cosmologists at the annual meeting of the American Astronomical Society, which is being held these days in Austin, Texas. Already in 2013, a study by astronomer Amy Barger and his then student Ryan Keenan, from the University of Wisconsin-Madison, shows that the galaxy in which we live, in the context of the large-scale structures of the Universe, resides right in the the limits of an empty giant, a dark and enormous region of space that contains many fewer galaxies, stars and planets than we can see in our immediate cosmic neighborhoo
Now, a new study carried out by another astronomer of the same University, also a student of Barger, not only confirms the idea that all of us live in the largest void known so far in the Universe, but also that This fact helps to reconcile the apparent disagreement between the two modes of measuring the Hubble constant, which cosmologists use to describe the speed at which the Universe expands.
The "hole" that contains the Milky Way (and us with it) is known as the "KBC vacuum" (by Keenan, Barger and Lennox Cowie, of the University of Hawaii), and it is truly enormous. In fact, it is seven times greater than the average of other vacuums observed, and has a radius of about one billion light years. For now, it is the greatest emptiness known to science. Keenan's first estimates, according to Barger's, held that the KBC vacuum had the shape of a sphere, with a growing "shell" made of galaxies, stars and other matter. Something like a huge bubble of soap with all the matter concentrated on the surface and almost completely empty inside. Now, Hoscheit affirms in his new analysis that this vision seems to be confirmed, since it is not ruled out by any other observational evidence.
Of course, observing reality on such a huge scale is something that has great difficulty for us. It would be like asking a bacterium to deduce that we live on Earth, and that it is part of the Solar System. In the words of Amy Barger, "it is extremely difficult to find consistent solutions from several different observations, and what Ben (Hoscheit) has shown is that the density profile measured by Keenan is consistent with cosmological observations."
In other words, Hoscheit has not been able to find any objection, nor any observational obstacle that goes against the conclusion that the Milky Way lies on the very edge of a gigantic void. A void that, in addition, has allowed to resolve the discrepancies that existed when using different techniques to measure the speed at which the Universe expands.
Have a wonderful day.
Reference:
Note: @sirknight started a contest and its daily topics are:
Sunday-light
Monday - Darkness
Tuesday-AnimalDeer
Wednesday-Structures
Thursday-ForcesNature
Friday-AmorBellezaFreedom
Saturday-Agriculture
