We've already told a chunk of universe that we are here...

HUMAN beings are fascinated by the idea of alien life. Me included. So the discovery, albeit a bit hypothetical so far, of a rocky, earth-like planet orbiting our nearest celestial neighhbour inevitably caught the headlines and the imagination.

Proxima Centauri is, as the name implies, quite close to our star, Sol. A mere 4.3 light years away. And inevitably the speculation has been about 'going there' or 'sending a probe'.

Thing is we have already arrived in a sense. In fact we have been arriving in increasing strength every year since the first radio transmission on earth (in the 1890s thanks to Marconi and a shack in Chelmsford, Essex). Whether Marconi's signals had the strength to reach Proxima is not clear.

But by now we are at the centre of a bubble of radio waves some 200 light years in diameter, and this is 90 plus light years beyond the new planet. Does that tell us anything?

Well maybe that the planet does not contain any advanced technological creatures since they would probably have heard us and responded by now. Or of course that it does and they are so smart and so appalled by what they hear and see that they have, perhaps wisely, decided NOT to pick up.

The point here is that what we ordinary mortals think about as alien life is very, very different from what our learned scientists expect. We might have little green thingies in mind; they have anything remotely capable of replication in their minds.

For that surely is the nature of life – replication to survive in the given environment. In fact when dear old Darwin postulated 'evolution' as the cause of all we see he had no idea what the mechanism might be. It took a long time and a lot of science to arrive at the gene and DNA. And oddly the idea of bits of something being passed from generation to generation had been talked about 2,000 years earlier by the Greeks. But nobody listened because, to be frank, the idea was, let's face it, preposterous!

So what do we really know? Well that lots of stars have planets. Frankly that should not be a surprise as our best theory of early celestial conditions virtually guarantees stars have planets and asteroids, stuff collides, some planets have satellites. And our chemistry tells us that things happen in an ordered way. So if just once out there the conditions are right then life is a given. Of course then it has to survive but that's a whole other ball game. Literally.

So some 4.3 light years away there is a red dwarf (not the best candidate for life giving properties) which is being orbited by a large lump of earth-like rock that is very close and may be so close it is trapped into having one face permanently facing the dwarf. While the other faces bleak, silent and very, very cold space.

Frankly it is not the best candidate for little green, brown or even grey men. But life? The kind scientists talk about? Maybe. After all it has twilight zones, between the scorch and the freeze. And scientists can theorise how good conditions can propagate there.

But get there? Send a probe? Its 4.3 light years away. It is just possible to imagine travelling at 1% of the speed of light. That's about 1,860 miles a second or 2,991 kilometres per second. But that's still going to be 4,300 years. When it arrives it will take 4.3 years for a signal to tell us it has arrived. Or did arrive. Anyway...

The problem is not whether we could accelerate to that speed. Or control our ship that long and that far. Given the right propulsion and long enough the answer is simply yes. But space is not empty and at those speeds it is actually quite crowded. Not big stuff (maybe?) but lots of dusty stuff. Fancy hitting a grain of dust at that sort of speed? Reckon we could build something to survive it? And do it again, and again, and...

So I'd say we are not going and indeed cannot, short of finding the wormhole solution (Mind you I keep reading about cranky stuff in the quantum physics environment and sometimes I do wonder...)

If we are not going then: Do we need to worry about 'them' coming to us? Well let's put it this way – if they are coming shouldn't we get some interesting radio stuff ahead of their arrival?

And won't they be batting off the 'stuff' of the universe all the way? I'm cool on this one. Our earth-bound problems are much more immediate.

Anyway, what do we do when they turn up in a burkini?