Atheism: The Ultimate Guide (COMPLETED)

18. The Big Bang Theory

There are a lot of misconceptions about what the Big Bang Theory actually is. Hopefully this chapter will answer any questions you may have about it! 

Keep in mind that I don't have a PhD in astronomy, astrophysics, or any other professions that dedicate their careers to studying theories like these. Therefore, there may be questions you ask me that I cannot answer, please do not get upset if you ask me something and I can't give you a satisfactory answer. 

Where did the idea come from?

In 1927, Belgian Catholic priest (as well as astronomer!) Georges Lemaitre (with a circonflexe accent over the i) theorized the Big Bang. In 1929, Edwin Hubble noticed that galaxies were moving away from us, as well as the farther away a galaxy is, the faster it's moving. This proved the Universe is still expanding, giving more way to a theory that at one point in time, everything was packed together. The theory was boosted even more by the discovery of cosmic microwave radiation (the echo of the Big Bang) by Robert Wilson and Arno Penzias. 

What is the Big Bang Theory? 

The Big Bang Theory is the most studied and most popular theory as to how the Universe came into existence. The biggest cosmic cataclysm ever! Basically, everything in the Universe was condensed into a tiny, hot, dense ball of light and energy particles. This state only lasted for about a fraction of the first second of time. Then, everything expanded and cooled down. Those particles formed atoms, which then grouped together, which formed the stars and galaxies we see today. The first stars created made molecules, leading to more stars being born. As all of this was happening as galaxies were mashing together while new stars were being born and dying. From this, things like asteroids, comets, planets, and black holes formed. Keep in mind that this was all happening over billions and billions of years.

Important note: the Universe is 13.8 billion years old, and the Earth is 4.5 billion years old. We know this by using radiometric dating of compounds, measuring old stars and globular clusters, and examining the leftover thermal radiation and rate of expansion from the Big Bang. 

The vast majority of the astronomical community accepts this theory, yet some have alternate ideas, i.e., eternal inflation and an oscillating Universe. The Big Bang theory is now the Standard Model of Cosmology!

Why is it called the "Big Bang"?

The biggest misconception about the Big Bang Theory is that it was a big explosion. Nothing exploded. It's called the Big Bang because it expanded to the big Universe we see today, and the expansion happened rapidly. A better reason is how on a radio program, Fred Hoyle named it that in a mocking manner, causing the name to stick!

What caused the Big Bang? 

That's something scientists are still studying right now! Some theorize it came from an ancient and unknown type of energy, but for the most part it's still pretty unknown. It's hard to adequately test theories to answer this question, unfortunately. However, that's why scientists are on the move right now to answer this question! 

Doesn't the Big Bang violate Einstein's speed limit? 

Einstein said that the speed of light is the maximum anything can travel within the universe. Since theories suggest the Universe expanded faster than the speed of light, doesn't that violate his law? Well, that did not apply to the inflation of the universe itself. In the beginning of time, the laws that govern our Universe did not/did not need to exist. 

What about Antoine Lavoisier's law?

His law states matter cannot be created or destroyed. Which brings up an interesting question, where did that matter come from? Doesn't that disprove the Big Bang? No, this is another misconception. You see, according to Einstein's law (E = [m times c] squared), energy is essentially equivalent to mass. The first law of thermodynamics doesn't specify it's about matter, but about the total amount of energy in a closed system. That's where matter cannot be created or destroyed. Therefore the first law of thermodynamics applies to mass, not just energy. 

A closed system is a system in which all the energy (potential or kinetic) must stay at the same level. If the amount fluctuates, it's not a closed system anymore. In order to call the Universe a closed system, that would mean the total amount of energy in the universe has to remain the same from its beginning until now.

Here's where quantum mechanics comes in. Quantum mechanics states that on a very small scale for a very short time matter can be created and destroyed. An example would be bubbles in boiling water. 

Taking all of that into account, the Big Bang fits perfectly into the laws. Even if the laws didn't have to matter at the time (since it was the absolute beginning of everything). 

What evidence is there for the Big Bang? 

There are several big factors that lead scientists to the Big Bang Theory. Cosmological redshift, the cosmic microwave background, and element distribution.

Cosmological redshift is (using spectroscopy) the measurement of the rate of which galaxies are moving farther away from us, like what I mentioned previously. The Universe is still expanding, and the farther away a galaxy is, the faster it's moving away from us. If we reverse this, everything in the Universe comes back to a single point. 

The cosmic microwave background (CMB) is the remnants (electromagnetic radiation) of the Big Bang we can see in the Universe today. The CMB essentially confirms the Big Bang Theory. The microwaves cannot be seen by the naked eye and can only be detected using special instruments. The CMB also provides insight into the Universe as a whole. Most of the universe is made up of dark energy, the mysterious force that drives the accelerating expansion of the universe. The next largest ingredient is dark matter, which only interacts with the rest of the universe through its gravity. Normal matter takes up less than 5% of the Universe's matter. 

Element distribution plays a big part into the Big Bang as well. Astronomers could try to calculate how much of each element there should be, and if those numbers didn't match up to the observations the Big Bang theory wouldn't be valid. 

Fortunately, the predictions matched up pretty closely! In the Universe today, we see 75% hydrogen, 24% helium, and 1% everything else. Any discrepancy is easily accounted for by nearly 14 billion years of stars cooking hydrogen into helium and other heavier elements. 

Why can't you just accept that God created everything? 

If scientists did that, science wouldn't advance at all. Simply saying "God did it" describes no working mechanisms and makes no predictions - therefore it is not testable. We'd have no knowledge of nuclear physics if we'd just accepted the sun was created by God, as well as a great deal of technology that wouldn't be created. Most scientists have moved past God and are working towards finding the real causes of the Universe. Just because we don't have the answers now doesn't mean we'll never find them.

Some religious folk have even said that God was the reason for the Big Bang, and have accepted it as fact. It's disappointing God has to keep being dragged into everything, but it's a start. Soon God will be left out of the equation entirely as more and more people pursue science and accept the Big Bang Theory as the only method of Universe creation.