Friedkin narrates with breathless to-camera commentary, beginning with his work on his iconic movie, which piqued his interest in the topic. In Rome, he meets Vatican expert Father Amorth, and gets permission to videotape his ninth exorcism of Cristina. After talking with another formerly possessed woman, Friedkin attends the ceremony, during which Cristina writhes and screams in a feverish trance that looks like something from an American church healing service. Then Friedkin shows the footage to experts, who discuss the neurology, physicality and psychiatry.

The point is that, even if there is a psychological explanation, this has been called "demonic possession" throughout history in various cultures. So if everyone in the room with Father Amorth and Cristina believes this is a demon, that's the realty for all of them. It's kind of a dodge for what's clearly going on here, but Friedkin continues to press the point, talking to a Los Angeles bishop (Barron) who who believes in demonic possession but has his own hesitations.

There's also a comical tone to the medical experts Friedman consults. Neurologist Martin struggles to seriously discuss how to surgically remove a demon. Israeli doctor Fried's face is absurdly covered in plasters, and he produces an almost hilariously silly 3D diagram of the human brain. And then there's author Russell, who has written so many books on the devil that he feels depressed.

Ridiculously, the hysteria-inducing musical score is the most unsettling thing about this film. It's certainly unnecessary to accompany scenes of Cristina, who is clearly unwell, writhing and screaming. Friedkin's coda to her story is just as bonkers, but it's ramped up by the score and the film's breakneck pacing into something almost feverish. Friedkin reveals himself as a man who desperately wants to believe that he has captured pure evil on camera for real. But we have enough of that on our nightly news to make this look like something entirely different.

Earth operates to a specific timetable, as its rotation creates a rhythm of light and dark that informs everything that happens. Starting at sunrise, the film explores a variety of scenarios on each continent, mainly meetings between predators and prey. Thrilling set-pieces include baby iguanas trying to outrun snakes in the Galapagos, a mouse dodging a barn owl in Europe, a penguin on an epic work-day to feed its family, giraffes jostling for control of the herd. And scattered through are scenes of adorable pandas and the saga of a zebra foal trying to survive as it crosses the savannah.

This isn't to say that there's an actual narrative. Clips are isolated, connected only by the relatively simplistic voiceover, intoned beautifully by Redford even if we miss Attenborough's sense of mischievous wonder. Each sequence is also accompanied by an intrusive original score by Alex Heffes that insists on telling the audience how to feel, from jarring thriller-style chords when a life is in jeopardy to a jaunty comedy tune as bears scratch their backs on trees.

That said, the camerawork is extraordinary, getting so close to these animals that it seems like we can see the emotions flickering across their faces. Fish stare nervously as they hide in reefs from sharks. Enormous sperm whales cuddle with their families and then take languid vertical naps. A sloth hears a female's call and heads off on a swim to find her. The camera operators seem to have crawled right down into the grass, along tree branches, through caves and under ice-shelves.

Projected onto a big screen in all of its digital glory, this footage is spectacular. And yet the movie as a whole feels like a missed opportunity to explore how humans also fit in with this cycle of day and night. Until the end, there isn't even a hint that people live on this planet. And there's also a gnawing sense that this footage has been forced into this structure simply for context. In other words, this is more of a carefully crafted family entertainment than an informative documentary.

Caine recounts how he never dreamed he could make it big as an actor because he was Cockney, and not allowed to play a leading man. But a series of breaks caused a crack in the system (it was an American director who gave him his first lead role). This was the same time as The Beatles, Rolling Stones and The Who broke out, working class boys rocking the nation via pirate radio, because the BBC would never play something so common. But fame brought challenges with money, sex and drugs, which gave authorities a chance to crack down on the revolution.

While it's clear that this is only one element of the story, it's a vibrantly psychedelic one, offering plenty of cool imagery with movie clips of the young Caine and his fresh-faced cohorts, who teamed up in a secret creative collective in London. This is nicely reflected in the voiceover as Caine interacts with his old pals, sparking memories and inside jokes. It's fascinating to see how actors, musicians, models, photographers, designers and artists created a tight subculture.

Clearly this was an amazing time to be creative, as constraining traditions were discarded, allowing free expression and experimentation. This is depicted here with a variety of observations vividly portrayed in clips and recalled in voiceover. Each person has a distinct angle on the time period, exploring how films found new freedoms from censorship, music began to come from the the streets, photographers and designers started innovating and models became superstars.

The salient comment isn't that these people were enjoying swinging 60s London, but that they were the ones who created it. By the early 70s things began to change mainly due to their experimentation with drugs, which caused problems and even deaths among their ranks. And this illegal behaviour was just what the establishment needed to regain control over them. Although clearly enough of the cat had come out of the bag that it would never go back in.

In the early 1980s, amateurs began pushing the boundaries of roller skating as they drew crowds along Venice Beach, creating a phenomenon. Springing from black urban culture, this was open to all ethnicities. And with their elaborate choreography, the skaters became celebrities, doing it for applause instead of money. Then Hollywood turned up, looking to cash in by making movies with mainly white casts like Roller Boogie, Skatetown USA and of course Xanadu. And the reality was far more integrated than officials wanted it to be.

Present-day interviews offer first-hand background to these larger-than-life characters, most notably leader-mentor Mad. From an abusive home, growing up in a racially charged community, skating was a way to express himself and feel free. This attitude was contagious, helping others escape their troubled lives. "Roller dancing is my faith," one says. A strip of smooth concrete between the sand and the city called Disco Alley became their home, and they became a family. The film follows them into a hugely emotional reunion on the beach.

It also traces the collapse of the scene when their culture was stolen by both film studios and record companies. Sally went on a European tour with her band, and Mad dealt a blow to the group when he swapped skates for motorbikes. Then after 20 years of happily dancing and playing in mixed ethnic groups, crack cocaine arrived in Venice in the early 1990s, and the scene collapsed, taken over by gangsta culture and an over-aggressive police force.

The ethnic angle is significant, as Venice was the only beach area in Los Angeles where blacks were welcome, an artists' colony in which people could be whatever they wanted to be. The film traces the deteriorating situation from the 1965 Watts riots to the 1991 Rodney King verdict riots, creating a city ruled by fearful officials. This tension adds an element of urgency to the film, as dark undercurrents swell up to swamp a joyful scene. So after such a lively opening, what this doc says about American society is downright stark.