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.
The omnipresent nature of gravity, as with time, is something that we may never consider in terms besides those that relate directly to us, and Cox begins the episode by toying with our preconceived notions of this ostensibly consistent force by removing its effects completely.
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.
Eventually concluding in the two merging together, Cox made sure we realised one of the tiny dots whizzing around on the screen was our own sun, leaving us with a shared appreciation of the magnificence of the whole thing, whilst also making us rather glad we won’t be here when it happens. Damn you, Andromeda. Let’s blame Kevin Sorbo.
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.
In typically sweeping form, Cox covers neutron stars in commendable detail before moving on to atoms, black holes and supernovas, all the while delivering the unbelievable little factoids we all tune in for. In a fall of five feet, for example, the gravity of a neutron star would mean that, by the time you hit the floor, you would be travelling at four million miles per hour, and his demonstration of the proportion of empty space to mass in an atom also makes you honestly wonder just why you can’t walk through walls.
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.
But, bah, these are but tiny flaws in a great episode of a great show that should be compulsory viewing for just about everyone.
Next week, in the last of the series, Cox talks us through light and its part in our understanding of our universe.