The Scientific Secrets of Doctor Who

by Simon Guerrier

  ‘But…we can’t be!’ said Sarah. ‘Wooded glades, oak trees, tribes of indigenous people…’

  ‘Ah!’ said the Doctor.

  ‘Now what?’

  ‘So you admit they’re oak trees?’

  Sarah harrumphed.

  ‘Think about it, Sarah,’ said the Doctor. ‘Trails through the woods that seem like corridors. Blinking diodes in the walls. Farm animals that have evolved into killers. Stasis chambers that have given up the ghost. Then there’s the devolution of language – “left-tenants”, the “Uman” race.’ The Doctor glanced at the Elders, who were regarding him placidly. ‘These people have been on this ship for a very long time. Or rather, their forefathers have. Long enough for their physiology to adapt. It’s a generation ark ship, heading out to the stars. You see? The technology is the same as on the Ark.’

  ‘But what about the plants?’ said Sarah.

  ‘Brought on board to generate oxygen,’ said the Doctor. ‘At some point they must have spread from their biodomes, slowly taking over. Behind all of that forest is a gleaming spaceship interior.’

  ‘And the people?’ said Sarah.

  ‘What remains of the colonists,’ said the Doctor. ‘And the original crew.’ He glanced at the failed stasis pods to underline his point.

  ‘Those are dangerous truths, Doctor,’ said a woman’s voice from the doorway. It was crisp and clear, and somewhat bizarrely, had an East European accent.

  Sarah saw the Elders freeze. She turned to watch the Doctor approaching the doorway, just as a gleaming figure emerged into the dim light. It was humanoid, but made no pretence at replicating human form. It was smaller than the tribes people, about the height and build of Sarah herself, and appeared to be made from the same base metal as the walls. It was sexless, with a moulded human face, eyes that shone a brilliant, electric blue, and an open slit where its mouth should have been. It was carrying a gun in both hands.

  ‘The pilot, I presume?’ said the Doctor.

  ‘In a manner of speaking,’ said the woman’s voice. ‘I’m operating this drone, along with a handful of others, which are currently pacifying the colonists.’

  ‘How very timely,’ said the Doctor. ‘May I assume that we are cordially invited to the bridge?’

  ‘Too right,’ said the woman. ‘You’re going to explain exactly how you came to be walking about my ship.’ The drone hefted its gun, and indicated for them to follow.

  ‘Tally-ho!’ said the Doctor.

  The bridge, the pilot explained as they walked, was on an upper deck, accessible via a lift shaft that bisected the vessel through its midsection.

  The Doctor walked ahead of her, deep in conversation with the drone that had found them in the crucible – or rather, with the female pilot controlling it. Sarah couldn’t make out much of what was being said, but she gathered the Doctor was explaining about the TARDIS and how he and Sarah came to be on the vessel in the first place, while no doubt doing his best to charm any relevant information from her.

  After a while the forest began to thin, and the canopy gave way to brightly lit corridors, of a kind so familiar to Sarah. They were functional and clean, with luminous panels, sliding metal doors and ancient, dusty computer terminals installed at regular intervals. The place felt deserted, as if it hadn’t seen life in decades. The drone guided them along, until, after what seemed like hours, they finally arrived at the lift shaft.

  ‘After you,’ said the Doctor, waving her through the portal and into the small metal box that would transport them up to the bridge. She noted the drone wasn’t joining them, instead retreating to an alcove in the opposite wall, watching them with its eerie, expressionless face.

  ‘Are you sure you know what you’re doing?’ said Sarah.

  ‘Sarah,’ said the Doctor, with mock chiding. ‘Don’t I always?’

  ‘Now I know we’re in trouble,’ she muttered.

  The lift shot up like a bullet in the barrel of a gun, almost knocking the Doctor sideways and forcing him to grab Sarah’s arm for support. He grinned that ridiculous grin.

  Moments later, the doors opened onto a small antechamber, devoid of any furniture or other signs of life. Stencilled on the wall, in bright red, foot-high letters, was the word ‘PROSPERITY’.

  ‘Of course,’ said the Doctor. ‘Now everything makes sense.’

  ‘Care to enlighten me?’ prompted Sarah.

  ‘All in good time,’ he said. He waved quiet any further protest as he crossed the room, heading for the hatchway that, she presumed, led through to the bridge.

  The pilot must have been aware of them, as Sarah heard her voice, booming out from the console. ‘Come in. And please accept my apologies. The place must be a state.’

  Sarah ducked her head and stepped through the hatchway onto the bridge.

  The first thing that hit her was the thick, cloying odour of decay. The second was the sight of the corpse in the pilot’s chair. It was partially skeletal, but dry, leathery flesh still clung to the bones, encasing much of the chest and skull. The eyes had dried and shrivelled away, and the lips had curled back, exposing a gap-toothed smile. Wires erupted from the back of the skull, snaking away into a hatch in the ground. Sarah could see fluids bubbling in them.

  ‘Oh… goodness…’ she said, trying not to balk at the sight.

  ‘Please don’t be alarmed,’ said the voice from the console. ‘I may look half-decomposed, but I’m still in there. The machines are keeping me alive. They won’t allow me to die until my mission is complete.’ She paused. ‘The name’s Ana, by the way.’

  ‘How long…?’ started Sarah, but found she couldn’t finish the question.

  ‘Three and a half thousand years,’ said Ana, ‘give or take a few.’ She laughed. ‘It’s been a long shift.’

  ‘Does it hurt?’

  The laughter stopped abruptly. ‘That doesn’t matter,’ said Ana. ‘I have a job to do. I promised I’d get Prosperity to landfall, and that’s precisely what I’ll do.’

  ‘Prosperity,’ said the Doctor. ‘The first of the great Ark ships to leave the Earth. You were declared lost after only three hundred years, a triumphant failure. The transmissions stopped. People mourned for you.’

  ‘We were never lost,’ said Ana. ‘Our mission continues to this day. Things might have gone a little awry…’

  ‘A devolved population who’ve forgotten the purpose of their mission, and live out their days according to complex superstitions derived from it. A crew that’s been dead for centuries. Farm animals grown into monstrous predators.’ The Doctor sighed. ‘Awry might be something of an understatement.’

  ‘But they’re still people,’ said Ana, ‘and they deserve to be saved. There’s a colony waiting for them. The first of its kind.’

  ‘Things have changed, Ana, while you’ve been navigating a path through the stars,’ said the Doctor. ‘Relatively speaking, millennia have passed on Earth. The human race has developed faster-than-light technology. They’ve populated the stars, forged immense empires, and encountered other sentient species. People pass unhindered between populated worlds. It’s really quite wonderful.’

  ‘Then it’s all been for nothing,’ said Ana. ‘The mission has failed.’

  ‘Oh no,’ said the Doctor. ‘Where would the universe be without pioneers to blaze a trail? Your mission inspired thousands of people to build more and better. It’s because of you that they succeeded. Don’t you see? It was a marvellous success.’

  ‘And yet those people down there in the lower levels – I’ve failed them,’ said Ana. ‘Their antecedents gave their lives to the stars. I owe it to them all to continue.’

  The Doctor crossed to the console. His fingers danced over the controls. ‘I could end it, Ana, if you asked me to,’ he said. ‘I could override the engines, boost them to unimaginable speeds. You’d reach landfall in a day or two. You could complete your mission, give those people a new world, where they can prosper.’ He turned to look at her. ‘But you know what
that would mean.’

  There was a moment’s pause. ‘Yes, Doctor.’

  ‘What?’ said Sarah. ‘What is it?’

  The Doctor turned to her. ‘I’m sorry, Sarah. There’d be no going back. The engines will be destroyed in the process.’

  ‘And she’ll die,’ said Sarah. ‘That’s the choice you’re giving her.’

  The Doctor nodded. ‘That’s the choice I’m giving her.’

  ‘But there has to be a way!’

  ‘Will they be all right?’ asked Ana gently. ‘I mean, the planet you’ve chosen. Will they prosper there?’

  The Doctor turned his head away from her, closing his eyes – as if in sorrow, thought Sarah. No, as if he was listening to something, tuning in to infinity…

  Then he opened his eyes. ‘I don’t know,’ he said at last. ‘I hope so.’

  ‘Well then,’ said Ana. ‘A leap into the dark. But that’s all this ever was anyway…’

  From the safety of the TARDIS, they watched Prosperity breach the atmosphere of the unnamed planet, lighting up like a silent firework with the heat of entry. Sarah studied the scanner until it was gone. She felt maudlin.

  ‘She was a brave woman,’ said the Doctor. ‘She gave her life for those people, in more ways than one.’

  ‘But it could all be for nothing.’

  The Doctor didn’t say anything. Then he gave her a broad, impish grin. ‘Let’s say we nip forward a few thousand years to find out.’ His hands moved swiftly over the TARDIS console and the engines gave a desperate, wracking wheeze. He pressed a button and the doors burred open. ‘Come along, Sarah. Chop, chop. No time to lose.’ He was out the door before she’d had chance to protest.

  Sarah expelled a long, heartfelt sigh. ‘Doctor…’

  * * *

  ‘There are worlds out there where the sky is burning, where the sea’s asleep, and the rivers dream. People made of smoke and cities made of song. Somewhere there’s danger, somewhere there’s injustice – and somewhere else the tea’s getting cold. Come on, Ace, we’ve got work to do!’

  The Seventh Doctor, Survival (1989)

  * * *

  On 21 June 1969, in Episode Ten of The War Games, the Time Lords found the Second Doctor guilty of interfering in the affairs of other people. As punishment, the Doctor was exiled to Earth, without the use of his TARDIS, just as the planet faced a series of new perils. He was furious at the idea. Like us, he’d be trapped on a single world.

  Except that a month later, on 20 July, a small box touched down on the Moon.

  ‘That’s one small step for [a] man,’ said Neil Armstrong as he ventured out of it, ‘one giant leap for mankind.’ An estimated 600 million people back on Earth watched this first human footstep on another world as it was broadcast live – thanks to new communications satellites, one of many technologies advanced by the race to the Moon.

  According to the Doctor Who story Day of the Moon (2011), the clip of Armstrong’s first moonwalk will become the most watched piece of footage in human history.

  * * *

  ‘The human race will spread out among the stars. You just watch them fly. Billions and billions of them, for billions and billions of years, and every single one of them at some point in their lives, will look back at this man, taking that very first step, and they will never, ever forget it.’

  The Eleventh Doctor, Day of the Moon (2011)

  * * *

  But that giant leap didn’t last long: just three and a half years later, on 14 December 1972, another small box blasted off from the Moon’s surface carrying astronauts Harrison Schmitt and Eugene Cernan back towards the Earth. No one has been back to the Moon since. (Sixteen days later on 30 December, BBC One broadcast Episode One of The Three Doctors – the story that ended the Doctor’s exile. By strange coincidence, he was trapped on a single world for almost exactly the period we weren’t.)

  At the time of writing, we are only in the early stages of plans to send people out beyond Earth orbit again – but that won’t happen until the 2020s, some fifty years after we last stood on the Moon. Why did we stop going into outer space?

  First, getting into space is expensive. The Apollo programme that first got man to the Moon cost $24 billion at the time – or $395 billion if we were to undertake the same project today. There are plenty of other worthy causes that need that kind of money. On the day of the Moon landing, protesters outside Mission Control on Earth demanded that the money spent on space exploration should be used to help the poor.

  Of course, that first Moon landing had to invent all the technology that got us to the Moon in the first place but, even with modern technology, space travel is still not cheap. To escape the strong pull of Earth’s gravity, you need a lot of thrust and that takes a lot of fuel. The more you send up into space, the more fuel you need to get it there, so the amount of stuff – or people – you can take up is very strictly limited. One NASA estimate is that it costs about £14,000 for every kilogram sent into space. Virgin Galactic offers members of the public the chance to fly, for a few minutes, more than 100 kilometres above the Earth – the official definition of the height at which space begins. Tickets are on sale for $250,000 each.

  Besides the cost, space is dangerous. The Ambassadors of Death (1970) saw the Doctor on the trail of a missing space capsule. Between the broadcast of its fourth and fifth episodes, events on screen were mirrored in real life as an oxygen tank ruptured on Apollo 13 on its journey to the Moon. With limited power, loss of heat and little water, the crew just got back to Earth – but missed their chance to walk on the Moon. In fact, two days before Neil Armstrong took his first steps on the lunar surface, US President Nixon pre-recorded a TV address, in case something went wrong and the astronauts were stranded on the Moon, where they would have died. Luckily, the message wasn’t needed and Armstrong and his crew got home safely.

  Others were not so lucky. The following year, the three-man crew of Soyuz 11 were found dead when their capsule arrived back on Earth, due to a mechanical error. The space shuttle Challenger exploded in 1986, as did Columbia in 2003 – in each case killing the whole crew. Just training to get into space could be dangerous: a sudden fire in 1967 killed the crew of Apollo 1 as they practised their launch sequence, their space capsule still on the launch pad. The following year, Yuri Gagarin – who, in 1961, became the first man to go into space – was killed in a plane crash while training for a space mission. People working on space rockets have been killed in explosions, as have people living nearby when rockets have gone off course.

  Astronauts go into space well aware of the risks. In fact, in 2004 (after the Columbia accident) NASA thought it was too dangerous to send astronauts on a repair mission to the Hubble Space Telescope – but the astronauts lobbied to be allowed to go, and NASA ultimately let them. In 2014, one of Virgin Galactic’s spacecraft crashed during a test flight, killing one pilot and injuring another – but the company vowed to learn any lessons and continue with its programme to get members of the public into space.

  Once you are up there, space presents lots of problems for the human body. Being weightless weakens your bones and tissues because they don’t need to work as hard in the low gravity. The circulation of your blood and lymphatic fluid can also be affected. Gravity helps food pass through our bodies, so digestion is more difficult in space. Weightlessness causes problems when you go to the toilet or if anyone is sick – astronauts have had to deal with stinking matter floating round their spacecraft.

  It’s a three-day trip to the Moon, so with a day on the Moon’s surface you need a week’s food for each astronaut – all of it packed into your spacecraft when you launch (because you can’t just nip out to the shops if you run out of anything). You also need oxygen, spacesuits, washing things, changes of clothes… To get to Mars takes at least 150 days. Think of all the food and equipment you’d need to take, even for a small crew – and Mars is the second closest planet to us.

  There’s more. Astronaut James Irwin was t
he eighth person to walk on the Moon. While there he suffered something like a heart attack. The stress of the mission might have worsened a pre-existing condition, but other astronauts have shown disturbances in the rhythm of their heartbeats while in space. They also suffer sickness from decompression, the effects of pressure in the body’s tissues, weakened immune systems, and there are effects on sleep, balance and eyesight, to name but a few. Astronauts might be exposed to dangerous radiation in space – or even from the ultrasound imaging tools they use on their spacecraft.

  There are psychological effects, too. It’s not only the stress of going into space and facing those dangers. Returning to Earth, some astronauts have struggled to fit back into everyday life – it just seems boring after you’ve been in space.

  * * *

  ‘You took me to the furthest reaches of the galaxy, you showed me supernovas, intergalactic battles, and then you just dropped me back on Earth. How could anything compare to that?’

  Sarah Jane Smith, to the Tenth Doctor, School Reunion (2006)

  * * *

  If it’s extremely expensive and very dangerous, is it worthwhile going into space? What do we get in return? The answer to that question says a lot about our relationship with space since we first walked on the Moon.

  We learnt a lot by going to the Moon. For example, Neil Armstrong and Buzz Aldrin set up a series of mirrors on the lunar surface. Scientists on Earth then fired a laser – a very accurate beam of light – at these mirrors, and measured the precise time it took for the laser to bounce back to them: it took 2.4 seconds. A laser beam moves at the speed of light (299,972,458 metres per second). Halve the time it takes to get to the Moon and back, and multiply that time by 299,972,458 and you have a very accurate measurement of the distance from the Earth to the Moon: 359,966,949.6 metres. Repeating the experiment over many years, we now know the Moon is getting further away from us, by about 3 cm every year (the opposite of what happens in the year 2049, during Kill the Moon!).