You can’t place the word’s “Big Bang Theory” on a Facebook post without getting a thousand answering posts saying that it’s a lie. That is unless you’re referring to the popular TV show of the same name; and sometimes even then Creationists will use that as an excuse to weigh-in with their nonsense. However, most of this a result of wishful thinking and laziness on their part; Wishful thinking in the form of Religious Faith in wanting the Bible to be true, and laziness because just a few minutes spent watching YouTube videos on the subject would supply them with the necessary information they need to see that the Big Bang is the best Theory for explaining how the universe developed.
Let me stop right here to say that NO Scientist makes any claims as to what existed before the Big Bang or where the material that comprised the original “stuff” came from. All they assert is that all of the space, matter and energy of the universe must have been, at one time, compressed into a very small space; so small that the pressures and temperatures were extremely high (maybe even in the billions of degrees).
The first to question if the universe might be finite in time or space in a scientific argument and to write about it, was Heinrich Wilhelm Olbers (1758-1840); and the question he posed is known as Oblers Paradox. It goes like this: Why is the night sky black? If the universe were infinite in extent and age then wherever you look, your line-of-sight would end with a star; therefore the night sky shouldn’t be black; it should be white, or light-grey from the continuous carpet of stars. Since even a child or a Pope can make an observation that contradicts this supposition we know it to be false, the universe is not of infinite age or is not of infinite size.
One clue of that the size of the universe might not be constant came from Albert Einstein. His calculations showed that the universe should be expanding or contracting; but that was contrary to the observations of the day which seemed to point to a static universe. So if the universe was static, there must be an unknown effect keeping it that way. He called this his “cosmological constant” (his unknown X factor) and inserted it into his equations to make it represent a static universe. He later called this his “greatest blunder”. (It was a blunder only in the sense that he should have stated it as a new unknown and ask the astronomers what they could measure.) Later scientists removed his constant and were immediately confronted with Einstein’s previous finding; that the universe can’t be static, it was either expanding or contracting. It turns out, as it often does, that the answer to that was shining down on us! It was contained in the light we receive from the stars.
We learned as a child that if you pass light through a prism, you get a rainbow that represents the colors that are in the light that enters it. White light, which from the sun, contains all the colors that we see in the world around us. Back in 1802 scientists Wollaston discovered black lines in these rainbows, or spectra, and puzzled over their origin. It wasn’t until 1850′s that Gustav Kirchhoff started examining these lines and discovered that they were absorption lines, made by the elements in the star (or galaxy) absorbing some of the colors from the light, as it passes through its atmosphere. These lines produce a kind of finger print, so to speak, of the elements in the star. This showed us that the universe around us is made of the same kind of atoms that make up the earth. The “heavens” are the stuff of Earth and vice-versa.
As far as the expansion of the universe, that answer comes from the left/right shift of these absorption lines. We all know that the sound of an approaching ambulance sounds higher pitched when it is approaching than after it passes. This is called the Doppler Effect (i.e. sound waves sound high when they’re closer together; so as an ambulance approaches, it squeezes the sounds from its siren closer together, and “pulls” them farther apart as it recedes). Light also can be squeezed and stretched in this way, moving the absorption lines of the spectrum proportionately. When analyzing light from a distant star or galaxy, these absorption lines will shift toward the blue end of the spectrum if the object is coming toward us and toward the red when it’s going away. The magnitude of the shift is proportionate to its speed, and since farther away objects are receding faster, its distance.
At that time, the entire universe was thought to consist of the Milky Way galaxy and surrounding space. Enter Edwin Hubble. In 1919, Hubble arrived at the Mount Wilson observatory in California, and using the Hooker Telescope noticed that some stars were strange looking smudges, instead of points. So he started taking spectrographs (i.e. pictures of these rainbows) of their light in order to determine their distances. He found that they were very much farther away than they would be if they were inside our Milky Way galaxy.
Hubble relied on the work of Henrietta Levitt who had shown that the absolute brightness of a group of variable stars called Cepheids was proportional to their periods. Thus by measuring the period and the apparent brightness one could determine their distances. Hubble used that knowledge to catalog the elements that were producing absorption lines in the smudges (galaxies), and what he found was astounding. 1) The farther away these objects were, the faster they were moving and 2) just about all of the smudges were moving away. He created a mathematical formula (the Hubble Constant) that we can now use to determine those 2 properties from a spectroscopic analysis of any star or galaxy. These results have been verified and duplicated by hundreds of scientists since that day. Hubble won a Nobel Prize for his work (and eventually got a space telescope named after him!). Today, even amateur astronomers can measure the red-shift of some galaxies with equipment that is commonly available.
Learning of Hubble’s discovery (even before it was published), George LaMaitre (a French physicist, mathematician and astronomer and Roman Catholic Priest) was able to see that the more time that passes, the larger the universe would be getting. He then imagined running the universe’s clock backward. Doing so, it would follow that all of the space, matter and energy in the universe was once in a smaller space; run it very far back and it would be in a very small space (Remember, time and space were also bound up in the original “ball” of matter/energy.) thereby formulating the basic idea of the Big Bang.
If you compress all of the space-matter-energy into a tiny space, it would be incredibly hot; somewhere in the neighborhood of 10 Billion Degrees. It was so hot, and compressed, that there was no way for atoms to exist, or indeed, any type of matter. Today’s Laws of Physics did not even exist then, since it was so small, hot and energetic that they could not coalesce. There was nothing but energy in that tiny spot. We have no idea how long it was in that condition, but when it did start to expand, it’s temperature began to drop and atoms then had enough space to start forming; and the laws of physics, as we know them, came into being.
Which brings us to the confirming evidence for the Big Bang; In 1948, scientists Ralph Alpher, Robert Herman, and George Gamow knew that if all of the above were true, it would mean that there should still be a tiny bit of that radiation left over, surrounding us like a thin cloud; and we should be able to detect it everywhere in space (since everywhere in space was at one time all together in one spot). Scientists used calculations to predict what temperature and frequency it should be, and started developing instruments to search for it. Alpher and Herman had predicted that a Cosmic Background Radiation (CMB) remnant should be seen at 5 KHz; unfortunately, their work was completely ignored. Around 1963 or 1964 Robert Dicke and Jim Peebles at Princeton, unaware of Alpher and Herman’s work, started working on an instrument to detect this CMB as well.
However, as luck would have it, in 1965 two Bell Laboratory scientists (Penzias and Wilson) accidentally discovered it while testing a satellite communications antenna. They were plagued by a hiss across the microwave frequency band, and they thought it was an imperfection in the antenna (See Image Top). However, when they contacted a nearby university to help them solve the problem, they discovered that the scientists there were working on finding that exact hiss, @ 5 Khz! It was a happy accident, and a Nobel Prize was eventually awarded to this team as well. (Side note: Scientists tell us that scientific discoveries are not generally heralded with “Eureka! I’ve found it!”, but more often its: “Hmmm, that’s funny.”)
We have now found, and mapped, the Cosmic Microwave Background (CMB) Radiation for the entire sky (see picture below). There are now 3 complete mappings of the CMB. The first was done by the COBE satellite. Another Nobel Prize was awarded to Smoot and Mather in 2006. A much more detailed map came later from the WMAP instrument. The most detailed map is from the Planck satellite. (You can follow this link to read more about it.)
Erik M. Leitch of the University of Chicago puts it like this:
“The Cosmic Microwave Background radiation or CMB for short, is a faint glow of light that fills the universe, falling on Earth from every direction with nearly uniform intensity. It is the residual heat of that tiny spot – the afterglow of the big bang – streaming through space these last 14 billion years like the heat from a sun-warmed rock, reradiated at night.”
Why don’t people know this stuff? This information is all over the internet; along with the evidence for evolution and the age of the earth. Again, it’s mostly because they’re lazy; but it’s their religious Faith that keeps them willfully ignorant of these facts; i.e. they don’t want to know.
The Hubble space telescope can see more than 13 billion years into the past, and we see that the farthest (oldest) galaxies are different from present day galaxies; they are younger and are not like the fully formed galaxies near us. Our modern Spiral galaxy type hadn’t had time to form until recently. Quasars, the violent youthful stage of stellar objects, can be seen several billion years away (ago) but we see very few of them nearby (recent).
We also see that white-dwarves have formed throughout the history of the universe from stars that are less than about 1.4 solar masses. These stars form after their hydrogen and helium fuel is exhausted. They are not heavy enough to collapse further to form neutron stars, or black holes. They are very dense, and most of these still exist. One can calculate the cooling rates compared to their observed brightness to get an upper limit to the age of the universe.
While the Big Bang may appear to some as a divine creation event, it is certainly not the one described in the Jewish creation myths of Genesis; and nothing about the Big Bang or the subsequent development of the universe implies a creating intelligence that is interested in us at all. The greatest part of the universe (99.99999%) would be instantly fatal to any humans who ventured there without modern technological protections.
The above cosmic observations and discoveries fit together with great precision into the Big Bang Theory. If you were to do away with the Big Bang theory then you the have unenviable task of coming up with a new theory that answers all the questions that the Big Bang Theory currently addresses. You’d better get to work! (I’ll alert the Nobel Committee!)