The observable universe has been expanding since the big bang, and the speed of this process is known as the Hubble constant. From her important parameters such as the age of the Universe and some of its basic properties, so the interest of scientists in clarifying the meaning of this constant is understandable. But sometimes it happens that more precisely, the more confusing, and this is the very case … 
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Hubble bubble in the artist’s view (illustration Wessel Valkenburg / Falcon). You can find out this figure by two ways: either measure the CMB, which is not so long ago with unprecedented accuracy was made by the spacecraft “Planck”, or calculate it from the speed of removal closest to Milky Way galaxies. It turns out something around 65–70 (km / s) / MPk. AND this “about” is very confusing for scientists. As reasonably notices Valerio Marra of the Institute of Theoretical Physics University of Heidelberg (Germany), what are the results of these the two methods are constantly different, “has always been a source intense debate in the scientific community. “And no wonder:” When you compare what these methods give, then you come across deviation of about 9%. “But we are talking about the most important physical constant … So, instead of referring to some unknown measurement errors, the researcher provides an explanation discrepancy between the two methods, based on the account of already known physical effects. The reason for the “delta” may be the existence of what the scientist calls the “Hubble bubble,” meaning part of the universe where the density of matter falls well below average for space. “Until now, our knowledge of our own space the surroundings were too inaccurate to judge whether we are in or not, ”Mr. Marra explains. – But let’s for a second Imagine that the Milky Way is located in a Hubble bubble. Matter outside the bubble will attract those in it galaxies so much that they begin to move faster than in average galaxy of the universe. In this case, the Hubble constant for our closest cosmic environment will be higher, but for the rest of the universe is lower. “And indeed, if the constant Hubble is determined for different regions of the universe then density heterogeneity of the universe can easily clarify apparent discrepancy between Planck’s results spanning the entire visible Universe, and observations of nearby galaxies. Anyone who believes that these two methods of measuring the Hubble constant match, default implies that we live in a typical region of space, generally homogeneous, scientists emphasize. But is it? After all, we may well be in the relatively poor matter corner of the universe. Applying your approach to explanation 9 percent discrepancy, astrophysicists narrowed the data gap, obtained by the two named measurement methods, only a quarter of the total volume. It is likely that the difference can be completely reduced to nothing, if we assume that the Hubble bubble, “in which we live “, has not a spherical shape, but an irregular, asymmetric one. Now Valerio Marra and colleagues are actively searching for models this kind. Research report published in the journal Physical Review Letters, and its preprint can be viewed on the site arXiv. Prepared from the materials of the University of Heidelberg. The screensaver image is owned by Shutterstock.
Galaxy universe
