The most divided Olympic Games in decades gets under way in China on Friday as Beijing becomes the only city to host both the Summer and now the Winter Games. As well as tight Covid-19 controls, the Games are fraught with political tensions over allegations of human rights abuses and boycotts.

Most of the snow on the slopes where the Olympic events will take place is man-made.

But inside an indoor rink where the icy climate is maintained by massive freezers at the side of the dome, six-year-old ice skater Yiyi doesn't care how Beijing is making the Winter Games happen.

She just can't wait to see it. She wasn't even born the first time the Olympics came to town. Now she's inspired by it.

"It's very exhausting but she presses on," her mum told me, after we'd watched her daughter in a lesson with a coach. "She won't leave until she learns how to do all the moves. She doesn't quit."

But this is as close to the action as she is going to get.

Yiyi and her mum can't go to any of the events. The Winter Olympics is happening in Beijing, but almost everyone here is excluded from it.

China is in the middle of a renewed effort to maintain "zero Covid".

So authorities have decided that no tickets will go on sale to the general public. Only members of the ruling Communist Party or staff from government-controlled companies are being invited, and even they have to abide by strict testing and restrictions.

As Yiyi's mum was telling me how disappointed she was that they could only watch the Games on TV, the six-year-old jumped in, making sure I knew that she was definitely going to be watching.

Spectators are just one part of China's strict Covid prevention measures.

The athletes and officials are all inside strictly managed "bubbles" to try to stop any spread. They can't leave. Anyone travelling between bubbles in official cars or coaches has been told that, in the event of a crash with a member of the public, they must stay in their vehicle. They must not make contact.

But it's not just Covid that makes these games unusual.

There's confrontation over China's human rights record. Senior officials from the US, the UK and more than a dozen other governments aren't coming. China's leaders, and state media, have dismissed the diplomatic boycott as "politicisation".

A dad who was watching his son at the ice rink where we met Yiyi shared that view. He told us the Games is just about sport.

"I think sports are sports and they shouldn't be mixed with politics," he said, speaking from behind his mask, wrapped up in his thick coat. "The Games belong to everyone and we should a participate and watch. Politics is just politics."

Five words make up the official slogan of Beijing 2022: Together for a shared future. It's similar to one of President Xi Jinping's buzz phrases, if you can call it that - building a shared future for mankind.

You see the slogan on posters at bus stops and attached to walls around the city. It's in propaganda videos from state media too. We found a "Together" video online with smiling children, singing and dancing.

It was released last month by the government in Xinjiang - the place where China denies it's committed genocide against its Uyghur minority.

A former Olympian who is close to US athletes this time told me why some of them are nervous about "sharing" this moment.

"I don't think a single athlete is going to speak out at the Games and nor do I think they should," Noah Hoffman told the BBC. "If I were there I would be keeping my mouth shut."

The 32-year-old skier represented the USA in 2014 and 2018. Now he advocates for sportsmen and women.

"The risk is just too great… this is a failure of the International Olympic Committee, it's a failure of leadership that athletes are in this position," he said when we spoke from his base on the US east coast.

He said he's been talking to teammates who are at these Games and they've told him the build-up experience is "nothing like what we've experienced before".

One athlete told him they'd not had a single meeting about "sport or their athletic performance". The preparatory meetings with the US Olympic authorities had focused on Covid-19 measures and personal safety for competitors while they are in China.

There are updated rules in place to allow athletes to express their concerns, but well away from the tracks, slopes, rinks and podiums. Chinese officials have warned athletes they must adhere to Chinese law at all times. Noah Hoffman thinks the idea that athletes are "at liberty to speak out" about China's mass incarceration and so-called "egregious" abuse of thousands of minority Muslim Uyghurs "is just false".

China's leader Xi Jinping has promised an efficient and safe Games. In many ways this looks like a normal Olympics. The torch relay in the days before the flame is lit. The universal branding emblazoned across a city. The Olympic rings popping up on myriad goods or services in shops.

But what is always a cold gathering feels much frostier this time round. This is a Games defined by the big fissure on the world stage, with China on one side and the US on the other.

Inside the bubble, athletes are just trying to get on with their sport.