Some Christians say that we must accept the Big Bang model for two reasons:
1. It’s required by the scientific evidence.
2. Since the Big Bang model includes a beginning for the Universe, we need it to show that there must have been a Creator.
Both of these are false.
First, the evidence that is offered to support the Big Bang model is consistent with other cosmologies. So it doesn’t require the Big Bang to be true.
Second, we don’t need the Big Bang to prove that the Universe had a beginning. We get this already from physics.
According to the second law of thermodynamics, the amount of usable energy in a system decreases over time. Therefore, energy always disperses and equalizes itself.
Here’s a practical example. If you leave a hot cup of coffee alone for a long period of time, what happens? It cools down to room temperature.
It does this because the concentration of heat energy in the cup must disperse itself until it’s equally distributed in the room. So, the coffee cools down, and the room heats up (slightly), until everything is at the same temperature.
Now let’s apply this law of physics to the Universe. If the Universe didn’t have a beginning, it would be infinitely old.
And if it were infinitely old, then an infinite amount of time would have already passed.
This means that there wouldn’t be any concentrations of energy left anymore in the Universe. It all would have dispersed and equalized, an infinitely long time ago.
Among other implications, this means the entire Universe would all be at the same temperature.
But when you look into the night sky, what do you see? A cosmos that’s full of very hot objects that we call stars, surrounded by vast expanses of very cold space.
Obviously, everything in the Universe is not at the same temperature. Not even close.
If an infinite amount of time had already passed, we wouldn’t see any stars. They would have all burned out eons ago, or ‘died’ in other ways. (Similarly, all the energy available to make new ones would also have been used up.)
But we do see stars. Therefore, the Universe’s energy hasn’t fully equalized yet.
This means there hasn’t been enough time for the equalization to happen.
And that means the Universe isn’t eternal. Therefore, it had a beginning.
So, if you want to prove that the Universe had a beginning, the Big Bang model is completely unnecessary.
Just go outside at night and look up at the stars.
Image credit: NASA, ESA, AURA/Caltech, Palomar Observatory