Who did not marvel at last Friday's opening ceremony of the Olympic Games? Four hours long; 14,000 performers; watched by four billion viewers. The only cloud in the Beijing sky was that London will have to match it in four years.

But wait! Maybe that won't be as hard as we feared. You know how we all thought it looked incredible? It turns out that some of it was.

Remember that cute pig-tailed schoolgirl in the red dress who chirrupped Ode to the Motherland at Friday's opening ceremony? It wasn't her voice. She was miming. The real singer wasn't deemed cute enough. So she was substituted on the stage because, as the ceremony's music director puts it, “we wanted to project the right image...for the national interest”.

And those footprint-shaped fireworks we saw on television padding across the Beijing sky? Impressive? Yes. Genuine? No. They were digitally faked. Computer graphics were inserted to enhance China's coverage of the ceremony because the actual fireworks were too difficult to film.

Yesterday China also owned up to deploying “cheer squads” in order to “create a good atmosphere” at Olympic venues blighted by blocks of empty seats. Yes, but for whom do the fake fans whoop and clack their batons? For everyone.

So if all it takes is computer wizardry, some lip synching and rent-a-crowd fans, London need lose no sleep worrying about trumping Beijing or about mounting costs. The tricksy opening ceremony can be faked, and even the stadiums themselves could be run up on a computer screen.

And when the world is entranced by a magnificent new London, who will notice the difference? Only those people who care about the Olympics.