Big Bang seems still popular. Explain Big Bang Theory. And explain why you believe it or don't believe it.
I want a mature answer.
Answers
The Big Bang theory is a cosmological model for the observable universe from the earliest known periods through its subsequent large-scale evolution.[1][2][3] The model describes how the universe expanded from a very high-density and high-temperature state,[4][5] and offers a comprehensive explanation for a broad range of phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, large-scale structure and Hubble's law (the farther away galaxies are, the faster they are moving away from Earth). If the observed conditions are extrapolated backwards in time using the known laws of physics, the prediction is that just before a period of very high density there was a singularity which is typically associated with the Big Bang. Current knowledge is insufficient to determine if the singularity was primordial.
Georges Lemaître first noted in 1927 that an expanding universe could be traced back in time to an originating single point, calling his theory that of the "primeval atom". The scientific community was once divided between supporters of two different models, the Big Bang and the steady state, but a wide range of empirical evidence has strongly favored the Big Bang which is now universally accepted.[6] In 1929, from analysis of galactic redshifts, Edwin Hubble concluded that galaxies are drifting apart; this is important observational evidence for an expanding universe. In 1964, the CMB was discovered, which was crucial evidence in favor of the hot Big Bang model,[7] since that theory predicted the existence of background radiation throughout the universe.
The known laws of physics can be used to calculate the characteristics of the universe in detail back in time to an initial state of extreme density and temperature.[8] Detailed measurements of the expansion rate of the universe place the Big Bang at around 13.8 billion years ago, which is thus considered the age of the universe.[9] After its initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, and later atoms. Giant clouds of these primordial elements (mostly hydrogen, with some helium and lithium) later coalesced through gravity, eventually forming early stars and galaxies, the descendants of which are visible today. Astronomers also observe the gravitational effects of dark matter surrounding galaxies. Most of the matter in the universe seems to be in the form of dark matter, and the Big Bang theory and various observations indicate that it is not conventional baryonic matter (atoms). It is still not known exactly what dark matter is. More recently, measurements of the redshifts of supernovae indicate that the expansion of the universe is accelerating, an observation attributed to dark energy's existence.
Answer:
Let us first understand that a scientific theory is what it is, a theory. A scientific law is different from a scientific theory. My answer in brief:
The simplest way to explain the Big Bang Theory-- it says the universe as we know it started with a small singularity, then inflated over the next 13.8 billion years to the cosmos that we know today. The big bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now (and it could still be stretching). In 1927, an astronomer named Georges Lemaître propounded the theory of the Big Bang. He said that a very long time ago, the universe started as just a single point. He said the universe stretched and expanded to get as big as it is now, and that it could keep on stretching.
This theory explains how our universe began. About 14 billion years ago, all the matter that makes up the universe was squashed into an incredibly small space. Because the matter was so condensed, it wasn’t in any form we would recognize today. No atoms, or even particles. Suddenly, though, that matter went through a rapid inflation — an explosion, in a way. That’s the Big Bang. The result was a super-hot mass of matter, including light and charged particles such as protons and electrons. The matter cooled slowly over billions of years. As it cooled, it formed elements such as hydrogen. The matter also began to clump together into stars and planets. At the same time, the universe kept on cooling and expanding. In fact, the universe is still cooling and expanding today.
The Big Bang theory represents cosmologists' best attempts to reconstruct the 14 billion year story of the universe based on the sliver of existence visible today. The Big Bang can also refer to the birth of the observable universe itself — the moment something changed, kickstarting the events that led to today. Cosmologists have argued for decades about the details of that fraction of a second, and the discussion continues today.
Big Bang and Evolution or Creationism?
I am often asked, as a person who studied science, whether I believe in the Big Bang and Evolution or in Creation by God. I'd rather believe in God as the Creator. Out of many arguments, a couple of examples.
Big Bang did not explain how matters came into existence. We need pre-existing matters for the Big Bang to happen. It cannot happen out of nothing. The Big Bang Theory is like a printing press which exploted and resulted into a perfectly beautiful and colorful book. As for evolution, after the Big Bang everything would be sterilized by the extreme heat making it impossible for life to occur. Even if life appeared, a primitive unicellular organism cannot evolve into millions of species of plants, birds, animals and microorganisms. One accidental unicellular organism cannot evolve into mankind, mankind with male and female or with some exceptions, animals and plants and microorganisms with male and female reproductive systems.
