The question, “could the universe have always existed?” is really asking, “can the universe take God’s place?” Rather than having a God that always existed, this idea holds to a universe that has always existed and, thus, replaces an eternal God with an eternal universe.
The idea of an ever existing universe is necessary to complete the theory of evolution. It requires that something infinitely improbable will occur if it has an infinite amount of time to occur — which sounds more like a numbers game than science to me. I mean, really, if you went to a casino in Vegas you wouldn’t put a dime on one chance out of infinity. So I find it odd that some are really willing to risk their life on such improbability. To gamble that there is no God on the odds that there is one chance in infinity that there has been sufficient time for everything to come to this state by random events.
That aside: the universe could not have always existed because that idea is in direct opposition to the Second Law of Thermodynamics. This law of thermodynamics basically states that each time you use energy it is transformed into energy that is less usable. For example, if you burn a log in the fire you get ash and heat. Ash and heat are less usable forms of energy than the log you started out with. You can use the ash as fertilizer for a new tree, and you can use the heat to cook dinner. Yet no system is 100% efficient, and if it wasn’t for our sun, the earth would have grown cold and dead long ago. But even the sun will run out of energy some day — as is the same with every star. Thus, the universe is slowly running out of usable energy. There is only a certain amount of hydrogen in each star and after it’s gone every star and planet will grow cold. So, if the universe had always existed that means there is an infinite amount of moments leading up to the present moment. But we have a finite amount of usable energy. So over an infinite amount of time all the usable energy would be used up. Thus, the universe has not always existed because we still have usable energy.
Atheists agree that our universe was started by a “Big Bang.” The disagreement comes when we ask what made all the noise. Some say that the “Big Bang” was just one of a infinite number of explosions before it. Others say there was just the one, but our universe will spin on forever.
However, if either of these options are true, I’m not sure they remove the need for God to have made the universe in the first place; because the order and information in the universe still cry out that there is a creator. I once heard it explained by Ravi Zacharias . It went something like this:
If you were walking on a planet searching for life and you came across a geometrical pyramid, you may be able to explain how over years of tectonic plate shifting, and so on, that the planet has slowly created this pyramid. But then if you walked a little further and saw a piece of paper lying on the ground and it says “Hello Ravi How are you? I’ve been waiting for you.” There would be no doubt in your mind that it took an intelligent being to write that message to you.
There is a message in the universe: the information in DNA; the precise balance in a star of the gravity and the forces of the outward explosion; the balance of living thing on earth necessary to keep it habitable — so much order and precision. Information is not a product of time, but of thought. I leave you with this question: Which one takes more faith: believing in that one chance in infinity, or in an intelligence behind it all?
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