Wednesday, 29 March 2006

The end of the universe

Many of Easy FM’s listeners may be thinking that the world is coming to an end, now that James West, Mr Business Reporter, is leaving the station. So I thought that today on Mr Science we would have a chat about what actually might to our universe when its time is up.

The universe is old and massive. NASA scientists estimate that it is 13.7 billion years old. We don’t know yet how big it is, whether it is infinite in size – that is goes on for ever – or actually has a boundary of some kind, but we do know that at the moment, the universe is expanding – observations show that stars around us are getting further and further apart and are moving away from us.

But will the universe continue to expand for ever? We can see about 7 × 1022 stars in the universe – that is a 7 with 22 zeros after it, or about the number of grains of sand on all the Earth. Will the gravity from all these stars eventually force the universe to collapse in on itself into something like an anti-bigbang?

This theory is called the “Big Crunch”. What it predicts is that there is enough matter in the universe – the density of the universe is high enough – that gravity will eventually pull everything back into a single spot – the exact reverse of what is thought to have happened in the big bang that started the universe. This theory also allows for another big bang to arise out of the big crunch, making an universe that keeps alternating between big bangs and big crunches – like a balloon you blow up, then let the air out of, then blow up again and so on.

Another theory, and the one that is the most popular among scientists at the moment, is that the universe will not collapse in a big crunch, but will expand forever. If so, everything will get further and further apart, and colder and colder. Eventually, stars will no longer burn and black holes will sweep up stars. After this, everything will decay into elemental particles – not just the atoms that make things up, and not just the protons, neutrons and electrons that make atoms up, but down to the elementary particles that make these tiny things up.

There are other such theories of the end of the universe, but perhaps, in the end, we’ll be able to escape the death of the universe completely. Some scientists believe in multi-universes and the idea that perhaps when humans get smarter in the very distant future and have the ability to not only manipulate the Earth’s resourses, but all the energy in galaxy or the universe, then maybe we’ll be able to somehow slip into another of these multi-universes. Perhaps these other universes have different physical laws to ours and so could look rather different to ours. Some theorists even believe that we will be able to engineer universes to live in. Others even think that a big crunch might be a good thing as it would allow humans to harness massive amounts of energy – energy which could be used to process information quicker and quicker as the crunch came. As information is processed an increasingly rapid rate, it may seem to the human doing to processing that time was slowing down, thus making it seem like he is living forever! This is highly speculative, and I don’t even really understand it!

But what I do understand is that all this highly speculative science is not going solve the problem of James West leaving China Radio International, nor will the universe end when he does. So thanks to James for allowing me the chance to bring science to you every Friday, and I hope to continue doing it in the weeks to come, but without my little brother helping me along.

The mp3 can be heard here

1 comment:

  1. So... the universe is about the same age as Kelvs??