To answer the first question — how our universe could have come into being — imagine a house made of bricks, windows, doors and a roof. None of these parts came about on their own. They all had to be obtained and assembled. So when we look at a house, we know that it did not arise by itself, but that someone from the outside made sure it came to be.
Now think of our universe, full of galaxies, stars, planets, space and time, as well as various laws of nature. To claim that the universe created itself would be like saying that a book wrote itself without an author, or that a house could build itself without a builder. This, of course, makes no sense.
Just as a house needs a builder and a story needs an author, the universe too must have a first cause. It needs something outside of itself that created it. Otherwise, the universe would have had to exist beforehand in order to create itself, which is logically impossible.
Someone might, however, say: “Perhaps the universe has no beginning and no end. Perhaps it has always existed and needs no first cause.”
At first glance, this may seem quite plausible. But a closer look shows that it is incompatible with what we know from science and logic.
First point: The total energy of the universe is finite
The first law of thermodynamics states that energy within an isolated system can neither be created nor destroyed. It can only change its form. This means that the total amount of energy in the universe has always remained the same since it came into being.
If the universe had had no beginning, then an infinite amount of time would have passed until today. During this time, the usable energy would constantly decrease — for example, heat becomes ever more evenly distributed. Therefore, all the energy would long since have been used up if the universe had existed eternally.
In simple terms: imagine the universe like a clock powered by batteries. The first law of thermodynamics says that the batteries cannot be recharged or replaced. They can only lose power over time as the clock runs. Suppose the clock had always been running. Then the batteries would be empty today.
Yet we still see stars shining, planets orbiting their suns, galaxies moving through the universe. This means that the universe is still full of usable energy. This clearly proves that the universe cannot have existed for all eternity. It must therefore have a beginning and a cause.
Second point: The second law of thermodynamics confirms this
The second law of thermodynamics states that things in a closed system become less organized over time, and the energy we can use slowly disappears.
Put more simply: heat always moves from hot to cold objects, so that in the end everything reaches the same temperature. If, for example, you leave a hot cup of coffee standing on a table, it gives off heat to its surroundings. As a result it cools down over time and eventually reaches room temperature.
If the universe had always existed, then by now everything would have to be at the same temperature. Yet we observe massive temperature differences throughout the universe. For example, stars burn while space remains cold, and there is still movement and structure throughout the universe.
This proves that the universe is still full of energy and order and therefore cannot have existed for all eternity.
Third point: The Big Bang shows that energy had a starting point
The leading scientific explanation for the origin of the universe states that the universe emerged around 13.8 billion years ago from an extremely hot, dense state. Since then the universe has been expanding and cooling. The original energy has, over the course of time, been transformed into various forms such as matter and radiation.
This again confirms that the universe must have a beginning.
Fourth point: The cosmic microwave background radiation confirms a beginning
One of the strongest pieces of evidence for the Big Bang is the cosmic microwave background radiation (CMB), the residual radiation from the early universe. Today, scientists measure the temperature of the CMB at about 2.7 degrees above absolute zero (Kelvin). As the universe expands, however, the CMB cools down.
This is important, because in an infinitely old universe there would be no CMB with the observed properties and no systematic cooling. Instead, we see a limited amount of energy left over from the past, which has cooled and spread out over time. This too confirms that the universe cannot be eternally old.
We can therefore conclude beyond doubt that our universe must have a beginning and that something thus created the universe out of nothing.
If, at this point, you ask artificial intelligence or even some people, it is quite possible that they will offer you one of the following counterarguments.
1. An endless chain of causes
One counterargument goes like this: there is no need for a first cause or a Creator if our universe was caused by another universe, which in turn was caused by yet another universe, and so on, back into infinity.
Can that be so? Let us suppose you borrow a book. You ask a friend for a book about African elephants, but he first has to borrow it from someone else. That person asks another, and so it continues endlessly. If the chain never ends and no one actually owns the book, will you ever get it into your hands?
Of course not — the book would never reach you, even though it exists.
If the universe were part of an endless chain of causes and none of these causes had a true beginning, then we would never reach the present moment. In that case there could be no universe at all. But since the universe does exist, we know that it must have a beginning.
Moreover, an infinite chain of causes does not explain why the chain exists at all. Each link depends on the previous one, but none of them can explain why anything exists in the first place.
2. Particles arising from “nothing”
Someone might tell you that in quantum physics tiny particles can arise from seemingly “empty space.” Does this mean that a universe can, after all, arise from nothing?
No. Quantum fluctuations, in which particles seemingly appear and vanish, take place within space, time, energy and physical laws. They are therefore based on an existing foundation.
In other words: they take place within the universe and not in absolute nothingness. So they do not show that the universe itself could have arisen from nothing.
Logic and science clearly show that the universe came into being at a particular point in time and was therefore created by something. There must, then, be something that was not itself caused and that necessarily exists outside of space and time.