What if Rupert Murdoch hadn't bought The Sun in 1969? Quite possibly, Neil Kinnock would have become Prime Minister in 1992. Almost certainly, Britain would be less raunchy today. Undoubtedly, the Royal Family would have retained more dignity. Arguably, the Mirror pensioners might not have lost their money. And Manchester United might not have been strong enough to win the Champions League. Or, then again, it might not have made much difference at all.Of all the programmes in the What If? television series (currently showing on BBC4), the Murdoch question has been the hardest one to answer. On any view...