Keajaiban Dunia

The universe is a huge area, filled with a variety of components that can surprise us, including things that are far away from our shadows. The theory of modern cosmology initiated by Friedman in 1920 and is known also as the standard cosmological model. Standard cosmological model begins with the principle on a large scale, the universe is homogeneous and isotropic and the observer is not in a privileged position in the universe. This model also states that the universe should be expanding in a finite period, starting from a state that is very hot and dense.
Star is one of the objects that can be immediately recognized when we look at the sky, of course, besides the moon and planets . Star itself has several types and classes, but often when looking at the stars, we will directly compare it with the Sun. The stars in the sky are bound to each other in a gravitational bonds that form the Milky Way galaxy.
Milky Way is not the only one galaxy in the universe. Milky Way is only one of billions of galaxies that exist in the observable universe. Observable universe consists of galaxies and other materials which in principle can be observed from Earth at this time. Of course, light or other signals from these objects takes time to reach us.
Model of the Universe
In 1929, Edwin Hubble working in Carniege observatories in Pasadena, California measure the redshift of a galaxy far away. He also measured the relative distance by measuring the apparent brightness Cepheid variable stars in each galaxy. when making a plot of redshift against relative distance, Hubble discovered that the red shift of distant galaxies is increasing in a linear function of the distance. Distant galaxies are receding from one another, and gives the picture if the universe was not fixed but is expanding.
If so, it can be said in the past the universe was much smaller and farther into the past, the universe was only in the form of a point.The point is then known as the Big Bang, as well as the beginning of the universe that we can understand today. Expanding universe is limited in time and space.
Newton knew that if the description of gravity is correct, then the gravitational force between all particles with mass in the universe will cumulatively make the universe collapse. Therefore he proposed the infinite universe. Field equations Einstein proposed a dynamic universe (although Einstein himself initially, like most people until the 1920s, thinking that the universe is static.
Why this universe does not collapse like Newton and Einstein's predictions? The answer is none other because since the beginning of the universe has been expanding. In the universe expands, there are 3 solutions proposed to predict the fate of the universe as a kesluruhan. Now the fate of which will be experienced of course depend on the universe expands velocity measurements relative to the amount of matter in the universe.
In general, it is the third solution, the open universe, the universe is flat and the universe is closed.For an open universe, it will expand forever, if it is a flat universe forever, there will be development with the development rate approaches zero after a certain time. If the universe is a closed universe, it will stop expanding and begin collapsing on itself and will likely trigger another big bang. For the third solution, the universe will experience a slowdown in expanding as a result of gravity.
Current observations made at distant supernovae indicate that the expansion of the universe is accelerating, which is caused by the existence of dark energy. No such gravity that slows the development, dark energy would accelerate development. Well, if indeed this dark energy plays an important role in the evolution of the universe, then it is likely that there will continue to expand the universe exponentially forever.
Early Universe
But really, the universe we see today differs significantly with the past. If humans have the name of growth from infancy to adulthood, the universe too. Early in its history, the universe is an area that is very hot and dense.A situation that differs significantly from the universe that exist today that are very worthy of being a place hunia. When we look into the past, it will be found in the early history of the universe, it appears that the heat does not allow the existence of atoms, because electrons move freely and to state that earlier, separate nuclei into protons and neutrons, and the universe is plasma incredible heat which consists of particles of a nuclear sub. If we explore further into the early universe will be found if the universe had a starting point known as the big bang or a big explosion.
If the big picture of our universe from the Big Bang promote, then we will find that the universe expanded from a hot and dense plasma into a universe that looks pretty cool today. But in the history of its development, there are a few brief periods when the universe was about 1 minute in which protons and neutrons synthesized into nuclei (helium, deutrium, and lithium, along with single protons that form hydrogen nukeli).Then the electrons join to form nuclei of atoms when the universe was about 370 000 years. At this point the universe became transparent and the radiation of photons off we can get information about the universe.
At the time the universe expanded wavelength shift becomes longer, so that the radiation temperature decreases to about 3 degrees Kelvin, forming what we know as the cosmic microwave background (CMB). CMB itself can be expressed as emission coming from the universe that is still very young and the particles are in a perfect thermodynamic equilibrium state. CMB becomes very important, because the CMB is an indication that carries information on the early universe. CMB results showed a high homogeneity or uniformity in temperature distribution of the universe.
The contents of the universe itself is quite diverse, not just what can be seen.From the detected, it is 5% of the universe consists of matter (atoms that make up stars, gas, dust, and planets). And there is 25% of the universe is filled by dark matter, new particles are even beum can be detected by any laboratory on earth. While 70% of the universe filled with dark energy, which energy is distributed evenly and still be sbeuah unsolved mystery for the world of science. Dark energy is thought that an integral vacuum energy of space-time or maybe it could be something much more exotic than that.
It seems that the conventional Big Bang model provides an alignment with the observation, as long as we provide a specific initial condition at the beginning of the universe: an expanding universe with the same density at all points in space, but there is a small disturbance that causes the universe evolved into present circumstances. Why is that?
From the standard cosmological model there are two major problems namely the horizon problem and the problem of curvature of the universe. The earlier of the universe, its density will approach the critical density, then regardless of the density of the universe now, on the early universe must be very small density differences.If not, then we will not be able to see the universe in the present circumstances. If the difference is large, then for a closed universe model, the universe had suffered great destruction or big crunch and to model the universe expands, the temperature of 3 Kelvin have been achieved before now.
While the horizon problem associated with the limit something that could be observed that have not been observed. In essence, we find the existence of the CMB temperature uniformity. Now this could be a uniform temperature of course because of the communication between the particles in the universe. But after we trace footsteps into the past, it was small and the horizon shows that after the big bang the universe expanded and the particles are initially able to communicate with each other will not communicate with each other again because it is outside the horizon is. Well how about that the particles are able to communicate with each other? The answer is to enlarge the horizon, never answers that allow for both these problems is the existence of inflationary universe.
What is Inflation?Inflation of the universe is an exponential expansion of the universe in a very short time early universe. Even a blink matapun slower than the inflation of the universe. Inflation occurs in less than 1 second. Fast is not it? Why should any inflation?
Inflation is needed to solve the problem of curvature of the universe and the horizon problem. With inflation, the horizon of the universe can be enlarged up to the circumstances in which the particles are within the horizon and could slaing berkomunkiasi. In addition to the expansion of the universe suddenly (exponential) then after the universe underwent inflation, after that it will expand to follow the standard model and could eventually reach the state today. Without inflation the evolution of the universe may have reached the end (great destruction to a closed universe) or a condition in which the temperature of the universe to reach the temperature of 3 K happened long before now.
But until now there is no definitive model of inflation. Various models of inflation are still being developed. The universe was indeed save a myriad of mysteries to be solved, but each one will appear mysteries revealed a new mystery.Space of time as a line of puzzles that await humans to fill in every answer.