The rate of expansion of the universe under a big question. Why can not cope physics?
The next time you eat muffin with berries, think about what happened with blueberries in the dough as baking sweets. Blueberries lying in one place, but as the expansion rolls berries started move apart. If you could stand on one berry, you would see all the other away from you, but the same would be true for any other fruit you choose. In this sense, the galaxy similar to berries in the cake.
From the moment of the Big Bang, the universe is expanding constantly. The strange fact is that there is no single location from which the universe is expanding - rather all galaxies (on average) are removed from the other. From our point of view in the Milky Way would appear that most of the galaxies moving away from us - as if we are the center of our universe bulochkopodobnoy. But look from any other galaxy - and the view is exactly the same.
To further confuse you, new research suggests that the rate of expansion of the universe may be different depending on how far back in time you look. The new data, published in the Astrophysical Journal, suggests that it is time to reconsider our understanding of the cosmos.
Cosmologists characterize the expansion of the universe simple law - the law of Hubble (named after Edwin Hubble). Hubble Law - the observation that the more distant galaxies are moving faster. This means that nearby galaxies are moving relatively slowly. Relationships between the velocity and distance are determined galaxy "Hubble constant" - 70 km / s / Mpc. This means that the galaxy is spent on about 90 000 km per hour for every million light-years distance from us.
This expansion of the Universe, when galaxies are slowly coming of distant galaxies, is expected by uniformly expanding cosmos dark energy (invisible force that is accelerating the expansion of the universe) and dark matter (of unknown and invisible form of matter, which is five times more than usual). The same can be observed in the cake with berries.
The history of measurement of the Hubble constant is full of difficulties and unexpected revelations. In 1929, Hubble himself believed that its value should be about 600 000 km per hour in a million light-years - about ten times greater than the measured today. Attempts to accurately measure the Hubble constant over the years have led to an unintentional opening of the dark energy. Search for information about this mysterious type of energy, which accounts for 70% of the energy in the universe, inspired by the launch of the best space telescope in the world (at the moment), named in honor of Hubble.
The catch is that the results of the two most accurate measurements are not consistent and do not relate to each other. As soon as the cosmological measurements have become so accurate that showed the value of the Hubble constant, it became obvious that it does not make sense. Instead of one, we have two conflicting results. On the one hand, we have a new precise measurements of the cosmic microwave background radiation - the afterglow of the Big Bang - do the mission "Plank", which measured the Hubble constant as the 67, 4 km / c / Mpc.
On the other hand, we have a new measurement of pulsating stars in nearby galaxies also incredibly accurate, which measured the Hubble constant as the 73, 4 km / c / Mpc. They are closer to us in time.
Both of these measurements declare its result as a correct and very precise. the measurement divergence is about 500 kilometers per hour in a million light years away, so cosmologists call it "live" between the two measurements - they seem to stretch the statistics in different directions, and it must be somewhere to collapse.
The new physics?
As she collapses? At the moment, nobody knows. Perhaps our cosmological model is wrong. It is evident that the universe is expanding faster closer to us than we might expect, starting from the more distant measurements. Measurements of the cosmic microwave background is not measured by a local expansion, and make it through the model - our cosmological model. It has been extremely successful in predicting and describing many of the observed data in the universe.
Therefore, while this model may be wrong, no one came up with a convincing simple model capable of explaining at the same time and this is all that we observe. For example, we could try to explain this new theory of gravity, but then other observations do not fit. Or it could be explained by this new theory of dark matter or dark energy, but then the other observations will not do - and so on. Therefore, if it is "stress" associated with the new physics, it must be complex and uncertain. Less interesting explanation will be "unknown unknowns" in the data due to systematic effects, and a more thorough analysis of the day reveal a subtle effect, which was lost. Or it could simply be a statistical fluke that will disappear when more data is collected.
It is currently unclear what combination of new physics, systemic effects or new data will allow the tension, but it is bound to become clear. as the expanding universe picture cake may be incorrect, and in front of cosmologists has a difficult task to choose a different picture. If the explanation of the new measurements need new physics, then the result will change our understanding of the cosmos.