Dear Steven Spielberg

With your blessing, the biggest ever sweep of the Universe in search of extraterrestrial life begins. But if, as you hope, the answer's out there, what makes you think it will want to reply to the question?

Let us imagine that you're an extraterrestrial life force: all things being equal you've evolved from the primeval soup and emerged into the warm glow of spiritual enlightenment and material enrichment. (Think of it as the cosmic equivalent of your good self surrounded by well-earned Oscars in your Beverly Hills mansion.)

As an alien life force you've worked hard to get where you are and are enjoying the fruits of your evolution. Now forgive me if I'm wrong, but I think the last thing you would want to do is draw attention to "the good life". (Do you not surround your Hollywood mansions with high walls and security systems?) Neighbours, if they're out there, are by and large bad news. They'll want to keep you chatting when you don't want to, borrow something you'll be anxious about them breaking or, as some have found in your neck of the woods, turn out to be Charles Manson.

Project Beta (Billion-channel Extra Terrestrial Assay) - the successor to project Meta, which you helped fund - scans a billion channels of incoming radio signals for patterns that might indicate the presence of life forms beyond our own solar system. Any alien responsible for such transmissions must be at least as advanced as we are - the odds being that they are considerably more advanced. This being the case, they might be curious to view from afar our world of Bosnian genocide, Ethiopian famine and our fingers still on the nuclear button in the South Pacific, but do you seriously think they would want to associate with us on an equal footing?

What if you contact aliens and find that they're not cute, marketable merchandise who want nothing more than to "phone home" but are instead a pernicious force intent on the ruthless exploitation of the human race for their own ends? Well all right, over here after 16 years of Tory rule we could handle that, but your American dream might just turn into a nightmare, transforming you from exploiters to exploited in one move.

It's very hard to believe that we humans might be the only intelligent life form in the vastness of the Universe but that just might be the case. (Even harder to believe that if there is a God, He made us in His image. Perhaps he should have consulted Max Clifford first.) But, then again, the odds are we are not the only ones and that being the case, we are far from likely to be the most advanced.

Perhaps the answer is out there somewhere. Perhaps they are monitoring all our electromagnetic radiations, from the Prince of Wales's phone calls to Blind Date. Perhaps the reason we haven't heard from "them" yet is that they are far too intelligent to get in touch with us, their cosmic neighbours from hell, with our back gardens full of Rottweilers and partly disassembled MkIV Ford Cortinas. Yes, they might be out there, but perhaps they are alien versions of Victor Meldrew, hiding behind the living-room curtains with the lights turned off until we stop ringing the bell and go away.