The Scientific Secrets of Doctor Who

by Simon Guerrier

  Other lunar experiments included studies of moonquakes, the composition of solar wind and the lunar atmosphere, the strength of the Moon’s magnetic field, heat flow from and electrical currents through the lunar crust, the properties of the regolith (the loose dust and rock covering the Moon’s surface), variations in surface gravity and levels of cosmic rays. Some 385 kg of moonrock was returned to Earth for further tests. All this study has given us new ideas about the formation of the Moon – and Earth – and the history of the Solar System.

  But we didn’t just go to the Moon for the science. Only one of the twelve people to walk on the Moon was actually a scientist (Harrison Schmitt, the second-last person there, was a geologist). The race to the Moon between the USA and the then USSR was as much about politics as science – and once one side had won that race, it was much harder for any country to justify the expense. Ten more flights had been planned to the Moon after Apollo 11; only six were launched (one, Apollo 13, didn’t get there).

  Yet the effort of going to the Moon benefited us closer to home. The technology invented to get there led to improvements in everything from computers to non-stick saucepans. As we saw, communications satellites allowed those 600 million people around the world to watch the Moon landing live on TV. Satellite pictures improved weather forecasts, and assessments of erosion and irrigation. We now have maps on our mobile phones that use live connections to satellites to tell us exactly where we are. (Our new reliance on satellite navigation systems was used against us in The Sontaran Stratagem / The Poison Sky (2008)). For the time being, we can justify the cost and risks of going into orbit to launch and service satellites, and even have an international space station circling the Earth. We just don’t go any further.

  That may change – as we can see in Doctor Who. In Colony in Space (1971), Jo Grant is told why humans have settled on the bleak planet Uxarieus in the year 2471. On Earth, there is apparently, ‘No room to move, polluted air, not a blade of grass left on the planet and a government that locks you up if you think for yourself.’ (We’ll return to Jo and her feelings about space travel in Chapter 5.)

  If it’s currently difficult to justify sending people further than a near-Earth orbit, computers and robots don’t need the same volumes of food and water, and don’t have the same risks of disease or injury. An unmanned rocket or craft still costs a lot, but nowhere near as much as sending people. And something going wrong isn’t quite so disastrous as when there’s a loss of life.

  We’ve sent robots and probes to all the planets in our Solar System. The failure of Beagle 2 to land on Mars on Christmas Day 2003 inspired the loss of Guinevere One at the start of the Doctor Who story The Christmas Invasion (2005). Gadget, the friendly robot in The Waters of Mars seems influenced by exploration rover Opportunity, which landed on Mars in 2003 and is still sending us back data from the Martian surface. (Opportunity has since been joined by another rover, Curiosity, and both are now searching for evidence of life on Mars. So far they’ve not found any, meaning the known population of Mars consists entirely of robots.)

  Even the look of outer space in Doctor Who – all brightly coloured nebulae and star systems – is the result of unmanned technology we’ve sent into space. The Hubble telescope’s view of outer space isn’t distorted by Earth’s atmosphere, so it’s captured the brightest, most detailed images ever seen using visible light (rather than ultraviolet or other spectra).

  These probes and spacecraft have taught us lots about other planets, space and even the origins of the universe. As we’ll see in Chapter 5, they’ve taught us a lot about our own planet, too. They’ve even shown that Doctor Who gets its science right – if entirely by accident. In Planet of the Daleks (1973), the Doctor stops an army of Daleks by detonating a kind of volcano. On this particular planet, volcanoes don’t burst with hot lava but with molten ice.

  In 1973, that was a fun idea dreamt up by writer Terry Nation. But on 25 August 1989, space probe Voyager 2 flew by Triton, largest moon of Neptune, and spotted real ice-canos. It’s now thought there is cryovolcanic activity – the scientific name for ice-canos – on several other moons in the Solar System.

  Triton was Voyager 2’s last meeting with one of the planets – and their moons – orbiting our Sun. Launched on 20 August 1977, it sent us back data from Jupiter, Saturn, Uranus and Neptune before venturing on to study the edge of the Solar System – there’s some debate among scientists about whether it’s got there yet. That gives us some idea of the vast size of the Solar System: Voyager 2 is moving at 15.5 kilometres per second – 55,800 kilometres or 33,673 miles per hour. Even so, it took it 12 years to reach Neptune and it’s only just escaping the furthest reach of our Sun’s gravity after 38 years. (That’s more than seven whole lifetimes for the Doctor – when Voyager 2 was launched, the Fourth Doctor was about to face the Horror of Fang Rock).

  Voyager 2 – and its sister craft, Voyager 1 – are journeying out of the Solar System with a message to the stars. Each carries a record of sounds and images from Earth. It’s a sign of how long ago these craft were built that the sounds and images are contained on phonograph records – what we now think of as old technology. These records are a greeting to any alien life that the Voyager craft might encounter, the sounds and images chosen to represent the diversity of Earth, with greetings in 55 languages. The idea was that part of us – part of everyone – would travel with these spacecraft out into deep space.

  It’s a nice idea, but Voyager 2’s 38-year journey to the edge of the Solar System is almost nothing compared to the distance to the nearest star to our Sun. Proxima Centauri is 4.2 light years away – that is, it would take 4.2 years to get there travelling at the speed of light, 299,792,458 metres per second (or 1,079,253,000 kilometres or 670,616,600 miles per hour). Voyager 2 isn’t going anything like that fast: even at 15.5 kilometres per second, it would take 81,236 years for it to reach Proxima – and that’s our nearest neighbour!

  Space is enormous. It’s hard for us to get our heads round just how vast it is. So how can we possibly get out there to explore it?

  One solution might be spaceships that can travel close to or faster than the speed of light. There are several examples of craft that can apparently do this in Doctor Who, but it still comes at a cost. A ship would take hundreds of years of Earth time to cross hundreds of light years, though due to relativistic time dilation (which we’ll talk about more in Chapter 6), people on board would experience only a few weeks or years of travel time. However, if they returned to Earth they would discover that hundreds of years – even millennia – had passed, and everyone they’d left behind at home would be long dead.

  Alternatively, people might journey to other stars in ships that take thousands of years – just like in the story that preceded this chapter. Astronauts setting off from Earth would never see their final destination, and neither would generation after generation of their descendants. Civilisations might rise and fall on those spacecraft – as they do in the Doctor Who story The Ark (1966). Over 80,000 years, it’s possible that gradual evolution would mean that by the time people arrived at Proxima Centauri, they’d be a different species from the people back on Earth. (For more on evolution, see Chapter 11.) Or perhaps they’d arrive to find people already there – supposing that new, faster spacecraft had been invented on Earth in the millennia since they left. In fact, it’s possible they’d arrive at Proxima Centauri to find the ruins of a civilisation that left Earth long after they did.

  There are still two ways we can reach the stars. First, we can use ever better telescopes and technology to explore space in greater detail – we stay on Earth but let information about the distant universe come to us in the form of light and other kinds of radiation. As we saw in Chapter 1, in just the last twenty years we’ve discovered thousands of planets orbiting other suns. We might yet find life on one of these worlds, even if we can’t physically get there. And it’s just possible that that alien life will already know all about us because of the
other way we can reach the stars.

  In 1888, Heinrich Hertz sent a pulse of electromagnetic radiation to a receiver: the first undisputed man-made radio signal. Radio waves travel at the speed of light. In about a second, a radio transmission spans the gap between the Earth and the Moon. In less than five minutes it passes the orbital path of the planet Mars. As we know, in 4.2 years it reaches Proxima Centauri – the nearest star to the Sun. In less than ten years, it passes Sirius – the bright Dog Star binary system, which the Doctor points out to Captain Avery in The Curse of the Black Spot (2011).

  Our broadcast radio signals are not particularly powerful by cosmic standards and their strength decreases still further as they pass through Earth’s atmosphere and then spread out across the vastness of space. But over the past century, the sheer number of radio signals that we produce has increased enormously as we’ve invented things like radar systems and television. For around a hundred years, a bubble of radio noise has been expanding around our Solar System, spreading out across space at the speed of light.

  On 23 November 1963, the first episode of Doctor Who was broadcast from transmitters in the UK. The signals would have reached into space. It’s possible they kept going, and in early 1968 – 4.2 years later – they passed Proxima Centauri. As Doctor Who celebrated its tenth anniversary on Earth, that first episode had reached Sirius. As the Ninth Doctor made his debut in Rose (2005), the first episode reached the stars Rho Cancri (which we know to have four planets) and HR3259 (which we know to have three planets). As The Day of the Doctor was broadcast on 23 November 2013, the show’s first episode had covered 473,026,420,000,000 kilometres or 293,924,990,500,000 miles.

  * * *

  The Need for Speed

  Doctor Who has suggested lots of ways to cut down travel times in space – though they don’t always conform to the laws of physics as we currently understand them.

  Sleep through it – The Ark (1966)

  The Earth’s population is miniaturised and stored in trays, 1 million people to a cabinet, to be returned to normal size on arrival hundreds of years later. It’s not said on screen, but presumably they’re unconscious for that time.

  Skip it – Frontier in Space (1973)

  Earth ships ‘jump’ into hyperspace as a shortcut and almost collide with the TARDIS – suggesting it travels through hyperspace, too. Yet in The Stones of Blood (1978), the Doctor says hyperspace is a ‘theoretical absurdity’ (though a theory can be both absurd and true). He also calls it a different dimension – another kind of space.

  Bend it – Nightmare of Eden (1979)

  The interstellar cruise liner Empress and other ships can ‘warp’ across long distances, presumably bending space to make the journey quicker. In Planet of the Spiders (1974), a starship travels by ‘time jump’ which suggests space is being warped, too.

  Surf it – Boom Town (2005)

  A tribophysical waveform macro-kinetic extrapolator allows the user to ‘surf’ across space and time.

  Go faster – The Waters of Mars (2009)

  The Doctor says Susie Fontana-Brooke will pilot the first lightspeed ship to Proxima Centauri in about 2089.

  Make a hole

  Quantum tunnels in School Reunion (2006) are used to join distant bits of space. Matter transmission (or ‘transmat’) technology can also move people quickly – though in Doctor Who it’s usually for relatively small distances such as the Travel-Mat or T-Mat system from the Earth to the Moon (The Seeds of Death (1969)). The Time Lords have ‘open-ended’ transmats (The Five Doctors (1983)), but we don’t know what range that might mean.

  Go backwards

  With time travel, you can arrive on a far distant planet before you set off – but it gets complicated (as we’ll see in Chapters 6 to 10).

  * * *

  There are at least 2,000 stars within fifty light years of Earth and the majority of them almost certainly have planets. If alien creatures live on any of them, they could – just could – be watching Doctor Who. We might be stuck – for the moment – on a single world, but not the Doctor. He might be a fictional character, but he really is travelling on our behalf, far out into space.

  The vast scale of outer space is boggling. But at the very small scale, space is even weirder…

  ‘Oh, I wouldn’t open that door,’ said the man.

  Carefully not showing my surprise, I reached instead for the door on the right. He tutted.

  ‘And not that one either.’

  My hand froze on the plain white handle. I turned to the little man who’d come from nowhere. He really was remarkably odd, with his mop of untidy black hair and crumpled suit. A cloud of anxiety hovered around him, as though he’d borrowed someone else’s clothes and now found himself expected to make their decisions. It probably wasn’t helping that I was shouting at him.

  ‘But there are no other doors!’

  His drooping face managed to be both supercilious and nervous. ‘Ah, well, are you quite sure?’

  Ludicrous! We were in a large white room. It had two doors at the end and that was it. No windows. No furniture. Just a huge whiteness that gave nothing away.

  Yet, somehow, at the far end, was now a third door.

  I marched towards it, but the man scurried in front of me with a funny little run.

  ‘Please don’t,’ he begged. ‘It may no longer be safe.’

  ‘Safe? What do you mean?’ I growled.

  ‘It could be dangerous. It may not have been a moment ago. But now you’ve observed it, its behaviour may have changed. Perhaps one of the other two may be safe to open now. What about the one on the left?’

  With skipping strides he rushed up to the door I’d originally chosen. Screwing his eyes shut he twisted the handle, throwing it open with a flourish. His face split with delight. ‘Aha! I was right – look, another room!’ He danced through, the door slamming closed behind him.

  For a moment, I was alone again in that vast white room. Then the door opened just a crack. ‘I forgot all about you, I’m afraid,’ the man murmured dolorously. ‘Come on in. The water’s lovely. Only there is, sadly, no water.’

  I stood in another large white room, the little man dancing at my side.

  ‘Who are you?’ I demanded.

  ‘Me?’ the man blinked with sad surprise. ‘I’m the Doctor. At least I think I am. But that may not count here.’

  ‘Where is here?’ I was suspicious.

  He threw his arms up. ‘This? This is The Multivarium. And, anticipating your next question, no one quite knows what one of those is. A lesson. Or a prison.’

  ‘Are you my jailer?’

  ‘Are you my jailer?’ the Doctor snapped back, with cunning but no malice. He rubbed his hands together with the most ill-placed glee. ‘Oh, don’t answer. I can tell you don’t know. Doesn’t matter. We stand on a precipice of uncertainty.’

  ‘Huh?’

  ‘Didn’t I just tell you? The Multivarium was created at an intersection between parallel universes. Literally anything is possible here… anything and nothing. If you see what I mean.’

  ‘Frankly, no I don’t.’ I wasn’t sure I liked or trusted this Doctor. He seemed to just expect people to put up with him.

  He edged nervously towards a wall. ‘I swear there was a door here earlier. Ah well, there’ll be another one along in a minute. Or a year. Or at some point. Eventually. Probability, you see.’

  He settled down cross-legged on the floor and breathed horridly into a musical instrument.

  A long time passed. Or no time at all.

  A door was there. It didn’t flicker into existence. It simply stopped not being there. The Doctor seized the handle excitedly.

  ‘Is it safe?’ I asked.

  ‘Only one way to find out.’ He stepped through. ‘I’ve got a good feeling about this one.’ He vanished with a wail.

  There was a long, tense silence. And then a tiny cough.

  I leaned over the lintel. Tumbling down into a vast white nothing was the D
octor’s recorder. He was dangling over the abyss, clinging on to the door frame. ‘It, ah, seems I was wrong.’ He dangled there. I said nothing.

  ‘I say,’ the Doctor called. ‘Can you help me up?’

  The room had somehow stretched while we’d not been looking.

  ‘Almost a corridor now,’ remarked the Doctor. ‘How many doors would you say there were? No, it’s all right, don’t bother to count. I think the number is close to infinity.’

  ‘Don’t be absurd. It’s a hundred. Maybe two.’

  ‘You think so, eh? I’ve always thought the human mind had trouble with anything above seven, but there we go. Two hundred doors. Maybe.’ He rubbed his hands together happily. ‘Which one shall we choose?’

  ‘We don’t have to choose any of them.’

  ‘Aha! You’ve hit upon the heart of the Multivarium.’ The Doctor settled himself down on the floor, stretching his legs out. ‘All right then. Let’s choose nothing.’

  He lay down, and contemplated the ceiling.

  ‘Could you stop that?’ I asked exasperated.

  ‘Stop what?’

  ‘The humming.’

  ‘Oh, I am sorry!’ The Doctor sat up. ‘Just slipped into it. How much time do you think has passed?’

  ‘I don’t know,’ I snapped.

  ‘Neither do I.’ The Doctor frowned. He sucked a finger and held it up to the air. ‘No air flow. What a pity. Would have been rather helpful.’ He stood and dusted himself theatrically down. There was no dust here. ‘Maybe we should choose a door. Might break things up a little…’ He threw himself at a door handle before I could stop him. He pushed it down, letting it linger there a moment. ‘After all, what’s the harm?’