Why is our understanding of the universe need to be revised
The universe was born about 14 billion years ago in the Big Bang. Since it is continuously expanding. But we have learned about this a little less than a hundred years ago. In 1920, the American astronomer Edwin Hubble invented the greatest at that time telescope in the world, and his colleague, Vesto Slipher saw the red glow of the nebula - what today we call galaxies - and determined that the nebula appear to us red, due to the fact that removed from our planet. This effect is called red shift - was observed for all distant from the sources of the Earth (quasars, galaxies) radiation, which says that all the sources are removed from each other. In other words - the red shift means that the universe is expanding. Recently, scientists have wanted to calculate the exact rate of its expansion. It turned out that the fundamental inaccuracies may be present in our understanding of the universe.
So far there is no consensus at the expense of the speed with which space objects drifting apart
What is the Hubble constant?
Edwin Hubble made observations of Andromeda and was able to classify it as a star system. Opening astronomer has expanded our understanding of the Universe - now we know that it is filled with galaxies. Thus, Edwin Hubble discovered the cosmological law that characterizes the expansion of the universe. To calculate the rate at which the universe is expanding, it is necessary to use the proportionality factor - Hubble constant.
Using Hubble constant can determine the average value of the velocities of galaxies. The magnitude of the proportionality coefficient outputted scientists is about 500 km / sec per 1 Mpc. Recall that cosmic distances are measured in parsecs 1 parsec equals 3, 0857 • 1019 kilometers. And one Mpc - the distance of a million parsecs.
All that we know about the expansion of the universe
However, the moment that put the Hubble constant, astronomers who are watching the expansion of the universe, each time coming to the different values of the Hubble constant. And these values are not consistent with each other. A similar discrepancy casts doubt on our ability to determine the exact age of the universe, and even call into question our understanding of its fundamental laws.
So how fast the universe is expanding?
A group of researchers led by the University of Chicago astronomer Wendy Freedman measure the brightness of the red giants in distant galaxies. The study found that the distance from the Earth to the red giants proved easier to calculate than the distance to other stars. Thus, according to calculations astronomers universe expands at a speed of 69, 8 km / sec at 1 Mpc. It should be noted that the study results will be published shortly in the journal Astrophysical Journal.
This is interesting: Can reveal the gravitational wave, how fast expanding universe?
As you may have noticed, the results differ from those calculated Hubble. According to the work of Friedman and her team, the rate of expansion is slower than the rate at which calculated the other team of scientists in a recent study - it professionals focused on another type of star. However, the obtained results exceed Friedman expansion rate that was calculated in another study that measured the residue astronomers CMB after the Big Bang, also called microwave background radiation. Thus, the Hubble constant is the biggest problem of modern cosmology. Experts do not exclude that determine the speed of expansion of the universe, we can get closer to unraveling the mysteries of dark matter and dark energy.
By the way, on our channel in Yandex. Zen you can find out about the latest research in the field of cosmology.
Do we know the exact rate of expansion of the universe?
In the middle of the next decade, NASA experts hope to launch into orbit Wide Field Infrared Survey Telescope (WFIRST) - a wide-range infrared telescope. Scientists believe that with its help astronomers can more accurately measure the distance between the space objects. And this, in turn, can lead us to agreed values of the Hubble constant.
So it will look new NASA telescope
What do you think, as evidenced by the different values of the Hubble constant? Share your opinion in the comments and with members of our Telegram-chat.