Tag Archives: time dilation

The Age of the Universe

The age of the Universe, according to the current position of science, is approx. 13 billion years. Scientists regard this value as a number valid for everyone, independent of the observer. Indeed, anyone who has already learned about the bizarre, paradoxical consequences of the special and general relativity theory can immediately feel that something has been swept under the carpet here again.

According to the theory of relativity, time (duration) is dependent on the observer, it depends on the relative speed of the observer and the observed object. In the theory of relativity, the distance traveled in four-dimensional space-time is an observer-independent invariant, but neither the distance traveled in space nor the time required for this is independent of the observer.

A direct consequence of this is that we cannot talk about the age of the Universe or its size without saying what kind of observer these values refer to. Obviously, if we don’t leave the Earth, we can say with a good approximation that the age and size of the Universe are of the same value for every person on earth.

However, once we leave Earth, the situation will be different. In the twin paradox thought experiment, we see that if an astronaut leaves Earth at near the speed of light and returns after a few years in onboard time, he will find that much more time has passed on Earth during his journey. If we now ask the astronaut and his twin left on Earth, who are hopefully still alive, how old the Universe is, they will give two different answers. When they set out, they must have agreed that the Universe was the same age according to both of them. On arrival, however, they will already have a different opinion, the astronaut will say that the Universe is younger than his partner on Earth.

To increase the contrast a bit, imagine a situation in which alien astronauts bring life to Earth three and a half billion years ago, and when they are convinced that life has settled on Earth, they take off in their spaceships and at a speed very close to the speed of light they visit a lot of other viable planets and give life to previously lifeless planets everywhere. Then they return everywhere to see what happened. If they visit us these days and ask how old we think the Universe is, they will be very surprised, because there can be a difference of billions of years between our opinion and theirs. After all, they were constantly on the road, their own time passed more slowly than ours. They live in a younger Universe than we, who owe our existence to them.

To make the situation even more absurd, let us now contrast the positions of the Bible and science on this matter. Based on the Bible, theologians put the age of the Earth and the Universe at about six thousand years, while scientists accept the above-mentioned approximately 13 billion years as valid. They argue against age determination based on the Bible, that there are objects on Earth and in outer space that are obviously older than six thousand years.

We, on the other hand, can easily imagine an astronaut who has been traveling at a speed very close to the speed of light in his spaceship since the beginning of the Universe, so that, according to his on-board clock, only six thousand years have passed since the beginning of his journey, so he will say that the Universe is only six thousand years old. Of course, this does not mean that we can make the argument of the Bible acceptable, we only highlight that if we give up the concept of absolute space and time, as the theory of relativity does, we have to face unpleasant consequences.

So what we object to in today’s position of science: if we reject the concept of absolute time, then how can we say that the Universe has the same age for all observers. The two statements are not compatible. If, on the other hand, the age of the Universe depends on the observer, then the philosophical and scientific consequences of this should also be explained. In this case, we can easily find an object in the Universe that is older than we consider the Universe to be. A bizarre consequence of discarding absolute time is that different observers may measure the background radiation temperature differently.

The principle of relativity states that the laws of physics are the same in different systems. It’s so beautiful, really. But if we add to this the fact that observers in different systems measure the age of the Universe differently, then it is no longer so reassuring.

I would only ask future authors that when they talk about the age of the Universe, they should always add that roughly thirteen billion years is actually a subjective time, we earthly people measure, consider, and feel the Universe to be that old. And let’s not confuse this value with an extraterrestrial who will tell us a much higher or much lower value when we ask him about it.

December 9, 2012

English translation: January 5, 2024