@buchos: Look up in the sky. Every star you see is a sun just like ours. They have to be a certain size to work as a star, and it is probable that all these stars have planets circling around them just like mars and earth etc. are going around our star- the sun. But the nearest stars are a long way away. Even at the speed of light it would take hundreds or thousands of years to get there they are so far away, and these are all stars (some 100 billion of these) in our galaxy. Beyond there there are lots more galaxies, some estimates ar that there are 80 BILLION galaxies in the universe… They got to this number by studying a tiny bit of sky very intently and counting the galaxies that they could see, and they numbered in the thousands.
So: we have enought trouble talking to other life forms on this earth – dolphins, monkeys, dogs, and elephants: Communications with them are a bit basic at the most optimistic. If we met “a tree” on another planet, it would be life, but would it make much difference?
I think the idea of science fiction is great fun, but sadly , without the most amazing breakthough in space-time physics (now there’s an opportunity for you) we are not going to be able to get to the other side of our galaxy, let alone across to another neighbouring one… Regards, Robin and thanks for a cracking good question.
Robin’s answer is really good. I’d like to take a stab at this question from a different viewpoint.
bucho98, you’ve heard of the Big Bang Theory, right? Not the TV show – which is funny! – but the scientific theory that at some point about 13.7 billion years ago the universe was born by a massive explosion. Going by this theory, this means that everything is moving away from some point in the universe. So, our galaxy is moving away from all other galaxies.
13.7 billion years is a really long time to travel and you can cover a lot of distance in that time. This is why I think any planets that possibly have life are so far away from Earth. Who knows, if we existed 13.69999 billion years ago we might be doing I’m an Engineer between galaxies!