Well, I have been dealing with a few theists that believe that the big bang proves that the universe had a beginning. I’m tired of retyping this, so I figured I would make a nice handy blog post that I can turn these people to.
The Big Bang
How far we’ve come since the big bang theory was first proposed. Originally, theists, especially Christians, had a huge problem with the big bang theory. They thought that it explained how the universe came to be without God. It didn’t take them long before they figured they could bastardize it and use it to try and show the necessity of God.
The big bang is the explanation of the expanding universe that proposes that everything we see in the universe was once compressed into a singularity, and it expanded extremely rapidly in order to create the universe we see now. That is the theory. Now this hasn’t stopped some people from hypothesizing that all the mater in the universe came into existence at that time, but much of this is not necessarily based on physics, but is a philosophical projection based on the mathematical anomalies that can’t be solved.
How close can we calculate?
Well, the smallest measurement of time is thought to be a Planck epoch, or 10-43 seconds. This means that we can’t measure further back than that because the next interval of time would be 0 when calculating back, and that would make all calculations undefined, since division by zero would be necessary.
During this first epoch, it is theorized that all the forces of nature were unified. This means that gravity, the strong and weak nuclear force, and electromagnetism were all one force, and it was a state we can’t really begin to understand.
Does this prove the universe began to exist?
Well, saying the universe began to exist is one of those tricky things to talk about. Did all matter and energy and everything we know of now begin to exist out of nothing? Not likely. It’s one of those questions that is not going to be answered soon, but that doesn’t stop some people from saying that the universe came out of nothing, leading to much confusion.
There are many things that theoretically are possible, but in reality they aren’t. For example, theoretically absolute zero is the coldest temperature possible. That means that theoretically 217.13 degrees C below zero is the coldest temperature possible theoretically, but this temperature can’t be reached, since that would mean an absence of energy, which would mean an absolute absence of anything.
It is also by no means certain that an absolute singularity, where T=0, can actually exist. At T=0, matter and energy would become undefined for sure, and according to Christians, non-existent. It would certainly go against the law of conservation of energy if this were the case, unless the energy came from somewhere else. It could be that we can get to a point where beyond that it is impossible to go, but never reach the point where everything stops.
Now, there is also the question of whether nothing is actually a proper description of what would happen at T=0. With string theory, we get things that aren’t necessarily what we call the universe, but they theoretically still exist, even if there is no matter or energy in what we call the universe. This means that to say that prior to the big bang there was nothing is still debatable.
It is also possible that all the matter in this universe comes from somewhere else. Many things have been hypothesized, such as the idea that the matter in this universe comes from another universe. The idea of branes (membranes) colliding has also been suggested as a possibility stemming from string theory. A quantum fluctuation causing it has also been considered.
Conclusion
Although there are many things said about the big bang, and the beginnings of the universe, much of it is merely philosophical, and is by no means conclusive. The idea that nothing can exist is by no means determined either. This doesn’t stop apologists from claiming it though.
Of all the possibilities given, there are no clear answers. There are many many arguments, and the big bang theory itself is still argued about. Anyone that would suggest that there is no argument when it comes to cosmology has no clue what they are talking about. In all of astrophysics, the ideas behind the origins of the universe are the most contested there are, and it is just simply dishonest to assume that there is truth behind the argument that before the known universe started, there was nothing.