In the third instalment of Professor Cox’s fascinating tour of the processes and constituent parts that combine to form our universe, he turns to the force that moulds and governs the astral forms that we see when we peer into the skies, the force of gravity. Or, as we later discover, the non-force of gravity. Rather inevitably for any documentary about gravity with a decent budget, he takes a trip on the surprisingly busy Vomit Comet (the same plane that allowed Ron Howard such zero-G authenticity when shooting Apollo 13). Though only simulating a lack of gravity, this scene is great viewing if only for Cox’s regression to a the giggling ten-year-old he undoubtedly once was. After this, Cox turns attention upwards, and the scale of the episode increases to perhaps the vastest yet covered by a programme already somewhat keen on discussing the grander themes. Perhaps more so than in previous episodes, the CG really came to life in awe-inspiring detail, yet its most intriguing use was in a graphically (although, presumably, not mathematically) simple sequence demonstrating the intergalactic jostling match taking place between our Milky Way and the trillion-star galaxy, Andromeda. One thing illustrated particularly well was the relative nature of gravity in relation to the object responsible for the force. Stepping into a centrifuge, Cox takes a virtual tour around a few of the known planets, allowing us to see the effects of each gravitational pull on Cox himself. Going up to five Gs, the extra force contorts Cox’s face to an extent to which he, for the first time, actually looks like a man of 43. Knowing that, if we were somehow able to stand on the surface of the sun, our blood would be sucked right out of our feet is a piece of knowledge that just makes life better in general, too. Perhaps best of all, however, despite the subject’s lack of grandiose visual glamour, was the account of the creation of Einstein’s general theory of relativity. Cox was always going to struggle here, as trying to explain this to an audience of muggles must be like trying to teach a U21 footballer how to do complex eye surgery. But using a sweeping mountainscape as a metaphor for spacetime, Cox gave us a glimpse of the theory while stopping short of brain-aching bafflingness. Perhaps these thematic simplifications are frustrating for viewers seeking a more esoteric account, but they are necessary to keep the rest of us on board, and Cox once again knows just how far to go without alienating the ‘normies’. Finally, covering the supermassive black hole at the centre of our galaxy, around which our star orbits, Cox ends things on the reflective note that over the event horizon is where mankind’s understanding of physics ends. Another great episode, then, despite a couple of very minor niggles. In something of a first for the series, Cox’s description of the Earth’s gravitational influence on our humble moon never really hits the mark in the way some of the other inspired illustrations did. This may just be (see: almost certainly is) due to this reviewer’s general incompetence, but for the first time it yielded a less than clear grasp of a concept, even in the jargon-free terms in which it is expressed. Also the trip to the dilapidated Chaco fortress Pueblo Benito in New Mexico seemed somewhat unnecessary, as did Cox standing precariously atop a mountain whilst being circled by a helicopter cameraman. One can only presume Cox and his crew have a few air miles they need to use up. Next week, in the last of the series, Cox talks us through light and its part in our understanding of our universe. Read our review of episode 2, Stardust, here. Follow Den Of Geek on Twitter right here.
