UWisconsin: Study Supports the Idea We Live in a Celestial Void

[bystander]

Celestial Boondocks: Study Supports the Idea We Live in a Void
University of Wisconsin | 2017 Jun 06

[img3="A map of the local universe as observed by the Sloan Digital Sky Survey. The orange areas have higher densities of galaxy clusters and filaments. Credit: SDSS"]http://news.wisc.edu/content/uploads/20 ... void-2.jpg[/img3][hr][/hr]

Cosmologically speaking, the Milky Way and its immediate neighborhood are in the boondocks.

In a 2013 observational study, University of Wisconsin–Madison astronomer Amy Barger and her then-student Ryan Keenan showed that our galaxy, in the context of the large-scale structure of the universe, resides in an enormous void — a region of space containing far fewer galaxies, stars and planets than expected.

Now, a new study by a UW–Madison undergraduate, Ben Hoscheit, also a student of Barger’s, not only firms up the idea that we exist in one of the holes of the Swiss cheese structure of the cosmos, but helps ease the apparent disagreement or tension between different measurements of the Hubble Constant, the unit cosmologists use to describe the rate at which the universe is expanding today. ...

The new Wisconsin report is part of the much bigger effort to better understand the large-scale structure of the universe. The structure of the cosmos is Swiss cheese-like in the sense that it is composed of “normal matter” in the form of voids and filaments. The filaments are made up of superclusters and clusters of galaxies, which in turn are composed of stars, gas, dust and planets. Dark matter and dark energy, which cannot yet be directly observed, are believed to comprise approximately 95 percent of the contents of the universe. ...

[Ann]

I find this so interesting!

Terry Devitt of University of Wisconsin-Madison wrote:

The void that contains the Milky Way, known as the KBC void for Keenan, Barger and the University of Hawaii’s Lennox Cowie, is at least seven times as large as the average, with a radius measuring roughly 1 billion light years. To date, it is the largest void known to science.

The void that we are located in is at least seven times as large as average? It is the largest void known to science?

My gut feeling has long been that the Earth is so very far from average compared with other planets in the Solar System and the Milky Way. This new study suggests that our galaxy's place in the universe is also very far from average.

Wow. I can't help feeling that there is something wrong with the Copernican Principle, the principle that is taken to mean that the Earth can't be "special". I believe it can. Not so that the Earth can be governed by other laws of nature that the rest of the universe. Of course not! No, but in the way that so many factors seem to have come together to all reach optimal values here, on the Earth. Is the supervoid that we seem to live in another such factor of optimal value? Who knows? But at least it means that once again we are not average.

Ann

[Nitpicker]

I'm not convinced that all the factors for life are optimal on Earth. They are sufficient, for now, certainly, but I can imagine that life could be better. Maybe the next intelligent species to evolve on Earth will do better.

And what about the remaining 95% of the contents of the universe? It is a bit mysterious, this dark matter and energy. I wonder if any of this dark stuff contains life of some form?

But yes, I still think we're a bit special.

[rstevenson]

It's inevitable that the conditions which produced us will seem special -- to us. This is called the "weak anthropic principle". Perhaps our extra large void is somehow a significant part of those conditions.

Rob

[BDanielMayfield]

I find this so interesting!

Terry Devitt of University of Wisconsin-Madison wrote:

The void that contains the Milky Way, known as the KBC void for Keenan, Barger and the University of Hawaii’s Lennox Cowie, is at least seven times as large as the average, with a radius measuring roughly 1 billion light years. To date, it is the largest void known to science.

The void that we are located in is at least seven times as large as average? It is the largest void known to science?

My gut feeling has long been that the Earth is so very far from average compared with other planets in the Solar System and the Milky Way. This new study suggests that our galaxy's place in the universe is also very far from average.

Wow. I can't help feeling that there is something wrong with the Copernican Principle, the principle that is taken to mean that the Earth can't be "special". I believe it can. Not so that the Earth can be governed by other laws of nature that the rest of the universe. Of course not! No, but in the way that so many factors seem to have come together to all reach optimal values here, on the Earth. Is the supervoid that we seem to live in another such factor of optimal value? Who knows? But at least it means that once again we are not average.

Ann

Nice points Ann. I too have never been a fan of the Copernican Principle. For that matter, I very much doubt that Copernicus would be either, if he could see the extent to which his proof of our planet's non-centralness has been applied.

It can't be denied that the location of the Earth has been favorable for the development of the science of astronomy.
We can see out of our galaxy as well as we can due to our Sun's location inside the Milky Way, and now we find that the Local Group is inside by far and away the clearest wide open space we could hope for. I would imagine that it might be impossible to even see the large scale structure of the universe from locales deep inside Galactic Clusters, where most of the universe's planets must reside.

My my, isn't it nice to have such a favorable location! Why, it makes me feel positively special!

Bruce