Big Bang Theory
Big Bang Theory; It is the most well-known theory that offers an explanation of how the universe began. In its simplest form, this theory suggests that the universe began with a small singularity and then inflated for 13.8 billion years, as far as we know today.
Because with current instruments, astronomers cannot know the exact moment of birth of the universe, and our understanding of the Big Bang; It is based on mathematical theories and models. Additionally, astronomers can hear the "echo" of the expansion phenomenon known as the cosmic microwave background. Although the phrase “Big Bang Theory” has been very popular among astrophysicists for decades, it became popular in the mainstream media in 2007 with the comedy series of the same name, which began airing in the United States and was about the academic and home lives of several researchers, including an astrophysicist.
The First Seconds and the Birth of Light
According to NASA ; At the moment just after the universe began, the environmental temperature was approximately 5.5 billion degrees Celsius. The cosmos contained a vast array of fundamental particles such as neutrons, electrons, and protons. As the universe cooled, these particles broke down or coalesced.
This primordial soup is nearly impossible to observe because light could not move into it. NASA defines this situation as follows: Free electrons; It may have caused light (photons) to be scattered in a manner similar to the scattering of sunlight from rain droplets in clouds. But as time passed, these free electrons came together with a nucleus and formed neutral atoms.
This first light—sometimes called the “image” of the Big Bang—is more appropriately known as the cosmic microwave background (CMA). And it was first proposed by Ralph Alpher and other scientists in 1948, but was discovered by accident almost 20 years later.
According to NASA; Arno Penzias and Robert Wilson of Bell Telephone Laboratories were trying to build a radio receiver in 1965 and noticed much higher temperatures than expected. Initially, they thought that this anomaly was caused by pigeons and their droppings, but despite cleaning up the mess and killing the pigeons nesting inside the antenna, the anomaly did not improve.
On the other hand, the research team led by Robert Dicke from Princeton University was trying to find evidence of the cosmic microwave background and the team; He realized that Penzias and Wilson had found this out without realizing it. Both teams published their papers in the Astrophysical Journal in 1965.
Determining the Age of the Universe
The cosmic microwave background has been observed in many missions. The most famous of the space-based missions was NASA's Cosmic Background Explorer (COBE) satellite, which mapped the sky in the 1990s.
Several other missions followed in COBE's footsteps, including the BOOMERanG experiment (Millimetric Extragalactic Glow and Geophysical Balloon Observation), NASA's Wilkinson Microwave Anisotropy Probe (WMAP), and the European Space Station's Planck satellite.
Planck observations announced in 2013; mapped the background in unprecedented detail and revealed that the universe was older than previously thought: The universe was 13.82 billion years old, not 13.7 billion. Maps also gave rise to new mysteries; For example, why does the Southern Hemisphere appear slightly redder (warmer) than the Northern Hemisphere? Big Bang Theory; He says the cosmic microwave background is mostly the same wherever you look. Measurements of the cosmic background also provide astronomers with evidence about the components of the universe.
Researchers think that much of the cosmos consists of matter and energy that cannot be "sensed" by conventional instruments. This mystery is also; This caused the matter and energy in question to be named dark matter and dark energy. Only 5% of the universe consists of matter such as planets, stars and galaxies.
Gravitational Waves Discord
While astronomers could "see" the beginning of the universe, they were also looking for evidence of its rapid expansion. Theory; He says that in the first moment after the birth of the universe, our universe expanded faster than the speed of light. By the way, this statement does not violate Albert Einstein's speed limit theory, because Einstein said that the maximum travel speed in the universe is the speed of light. This theory of Einstein cannot be adapted to the expansion of the universe itself.
In 2014, astronomers found evidence of “B-modes” in the cosmic microwave background; As the universe grew, a kind of polarization occurred and gravitational waves emerged. The team detected this evidence using the Antarctic telescope called "Backround Imaging of Cosmic Extragalactic Polarization - BICEP2". John Kovac, a researcher at the Harvard-Smithsonian Center for Astrophysics; He says that they are very sure that the signal they saw is real and that it is in the sky.
But in June 2014, the same team; He said his findings may have been altered by galactic dust entering their field of view.
Researchers in both teams worked together in January 2015; He confirmed that the bicep signal is mostly (but not all) a glowing mass (en. stardust).
Faster Inflation, Multiverses, and the Startup Chart
The universe is not only expanding, it is also inflating rapidly. This means; As time goes on, no one will be able to detect other galaxies from Earth or anywhere else in our galaxy.
Harvard University astronomer Avi Loeb says:
“We will see distant galaxies moving further and further away from us, but the speed of these galaxies will increase over time. So, if you wait long enough, the speed of a distant galaxy will reach the speed of light. So what does this mean? Light will no longer be able to bridge the gap between us and this galaxy. "And if the galaxy moves faster than the speed of light relative to us, it will not be possible to communicate with a possible alien in this galaxy and the signal flow will not occur."
Some researchers believe that measurements of cosmic microwave background patterns of concentric rings are evidence that a universe existed before ours was born with the Big Bang.
Some physicists say; He claims that the universe we are in is one of many universes. In the multiverse model, different universes can exist side by side with each other, like bubbles next to each other. According to theory; In the first big push caused by inflation, different parts of space-time grow at different rates. These different universes could potentially have different laws of physics.
Theoretical physicist Alan Guth of the Massachusetts Institute of Technology (MIT) said at a 2014 press conference:
“It is very difficult to build models of inflation that do not lead to a multiverse. However, it is not impossible. So, I think there's still research to be done. But many inflation models lead to a multiverse, and the evidence for inflation leads us to; "It leads us to the point that we need to take the idea of multiverses seriously," he said.
As we try to comprehend the universe as we know it, it is possible that the Big Bang was not the first inflationary process the universe experienced. Some scientists believe that we live in a cosmos that undergoes inflation and deflation in regular cycles, and that we are currently in one of these phases.
Source
*Bilimfili - "What is the Big Bang Theory?"
http://bilimfili.com/big-bang-buyuk-patlama-teorisi-nedir/
