Of course, before asking ourselves this question, we must be sure that time really exists. Because there are various scientists who deny the greatest and defend that we really live in a world without time , which is an illusion. One of them, the English physicist Julian Barbour, has been defending this for more than 30 years.
All this comes because at the quantum level, on the scale of elementary atoms and particles, time has no meaning. That is why there are scientists like Barbour who argue that time is not a fundamental aspect of the world.
According to this physicist, the universe is nothing more than a great collection of moments and each one of them a collection of things. He calls the collection of all these moments the heap. There is no point in wanting to temporarily order those different moments. They simply are, period. Nothing changes in time because there is no time, which is an illusion created by our brain.
In essence, the reasoning of those who advocate a world where time is an illusion is as follows. Imagine you want to see the movie Gone With the Wind on a DVD player that randomly jumps back and forth: you are watching the sequence where Scarlett swears she will never starve again, then she appears when she meets Rhett Butler. Nothing makes sense to you, but the protagonists see no problem in it. In each sequence they do what they have to do and they always do. If you could stop the movie and ask them what they think at the time, they would answer you exactly the same as if you were watching the movie on DVD without that flaw.
In each sequence they always have the memories that correspond to that sequence. In the same way, each moment in space-time is like each of the sequences in the film and what you are in each moment, which is the now, is the product of your experience in that moment. His life, which in essence is his memory and memories, is a set of slides that cause the feeling of passage of time that we all have. Moreover, this sensation does not require the existence of previous slides, of previous moments: everything is contained in that particular slide of the universe.
