Curious Kids: will time stop?

Will time stop? Casandra, 11 years old, Epsom, England

Time began when the universe was created. If the universe ends then time will end too?

We think the universe began to form when it was squeezed into a very small space. For some reason we don’t yet understand, the universe immediately started expanding – getting bigger and bigger. The idea, about the beginning of the universe is called The Big Bang

In 1998scientists know that the universe is expanding faster but we still don’t know why this is happening.

Dark energy

It may have something to do with the energy of a vacuum. This may be a new type of energy field. Or, it may be an entirely new form of physics. To symbolize our ignorance, we call this new phenomenon “Dark energy” or dark energy.

While we’re still trying to figure out what dark energy is, we can already use it to predict various ways when the universe will end.

If dark energy weren’t so intense, it would take the universe an infinite amount of time to expand to an infinite size. Infinite means never ending, and in this case, time will never end.

However, if the dark energy is too strong, it will cause the universe to expand so fast that everything in it – even small atoms which is the building block for everything in existence – will be destroyed. In scenario Big Rip In this case, the universe will not expand forever.

On the other hand, the universe will expand so rapidly that it will reach a very large size at some point. that event, when the universe was enormous and all matter had been torn apart, and would come to an end. The universe will cease to exist, and time will end.

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There is another way that the universe could end. This is called Big crush or Big Crunch. In this scenario, the universe will at some point stop expanding and start shrinking again.

The universe will shrink, galaxies will collide with each other, and all matter in the universe will shrink together. When the universe will once again shrink into infinitesimal space, time will end.

Big Bounce

Some physicists think that Big Crunch perhaps not the end of the universe, but only in the middle before its destruction. According to this way of thinking, the universe originally had an infinite size, which would then shrink over an infinite length of time – until it was compressed as small as possible. When that happens, instead of ending, Big Bang appeared and the universe began to expand.

In scenario Big Bounce In this case, there was an infinite amount of time before the universe contracted into the smallest possible space, and an infinite amount of time when it expanded afterward. Time has no beginning and no end.

In some models Big Bounce, the universe only bounces once. Elsewhere, he goes through several periods big bounce in infinite numbers, constantly expanding and shrinking, like an accordion that never stops playing.

All of these scenarios show us what is possible, not necessarily what is true. For one thing, we still need to figure out what dark energy is. More importantly, there is no guarantee that our current understanding of how the universe works is correct.

One day, maybe 100 years or just a few weeks from now, someone (perhaps you?) will come up with a better theory to describe how the universe works. Maybe in the future we will know whether time ever comes and ends. Then again, perhaps the new theory will have a very different concept of time.

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Arina Apsarini from Binus University translated this article from English.

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