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The science of Doctor Who

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  • Publication: Focus
  • Date: August 2006
  • Author: Paul Parsons
  • Page: 32
  • Language: English

The amazing real science behind sonic screwdrivers, Cybermen, regeneration and more!

Have you ever wondered how Daleks make it up stairs? Whether K-9 is Tardis-trained? Or if a sonic screwdriver's really much good when it comes to putting up shelves? Paul Parsons investigates

WHEN DOCTOR WHO RETURNS TO TV screens in its 43rd year this spring, how will the science and tech of the Doctor's universe square. up against the real world? "Remarkably well," seems to be the resounding answer from experts in the UK's universities and research institutes. Whether it's the reason why the Tardis is bigger inside than out, why the Doctor has two hearts, or why the Cybermen hate us so much — they all have firm analogues in fact. Do we really need to know the science behind ail SF TV show? in fact, do we really need SF TV shows at all? (If course. not. But they're fun, they fire up the imagination and they offer escape from the humdrum. And for many of us, nitpicking about their science down the pub is the logical next step. So, get a round in, make yourself, comfy on the sofa (or behind it), and break out the jelly babies...


The truth about 'Time and Relative Dimension in Space'

The idea for a Police-Box-shaped Tardis came from BBC staff writer Anthony Coburn, who was writing the first ever episode of Doctor Who in 1963. The first thing that hits you about the Tardis is that it's bigger inside than out. In 1999, a scientist at Cardiff University figured out why this might be. Dr Chris Van den Broeck is an expert in Einstein's laws of general relativity (GR) - a theory of gravity that describes gravitational force as the bending of space in response to the matter placed within it. Van den Broeck realised that by choosing the right kind of matter to do the bending, and by arranging it in just the right way, he could use GR to manipulate space and time, and construct a 'bubble' of space that's bigger inside than out. To visualise it, imagine a two-dimensional rubber sheet with a 'lobe' attached to it (right). The lobe looks like a balloon, with a narrow 'throat' connecting it to the sheet. Now picture an ant crawling on the surface of the sheet. Where the sheet joins the throat, the ant finds a hole with a very small circumference. But if it crawls through the hole and along the throat it emerges into the lobe, a big bubble with a huge surface area. Now scale all that up a dimension, so the 20 sheet becomes 3D space. "Replace the circumference of the throat by surface area, and the surface area of the bubble by volume," says Van den Broeck. "What you then get is a large volume with a small surface area." Just like the Doctor's Tardis.


Can you really use sound beams to do up the bathroom?

The sonic screwdriver is the Doctor's answer to a Swiss Army knife. Undoing nuts and bolts from a distance using nothing but a beam of sound might seem far-fetched. But similar devices are now used for a range of tasks in manufacturing.

"You produce a focused column of oscillating air particles — sound waves — that's directed towards an object, say a screw. These set up high-frequency vibrations in the screw, causing it to rattle along in the direction of the threads to either tighten or loosen," says Professor Douglas Adams of Purdue University, Indiana, who is an expert in noise and vibration engineering (but no relation to the late, great Doctor Who script editor of the same name). Direction is controlled by rotating the sound beam clockwise or anticlockwise accordingly.

Christopher Eccleston's Doctor number nine also uses the screwdriver to weld metal. Indeed, most electronic components are now soldered in place using high-frequency sound to melt the solder. Welding is much the same process but at higher temperatures. Ultrasound can also cut holes, just as the sonic screwdriver does in the show. "I once attended a demonstration where acoustic energy transmitted into fluids punctured and then disintegrated a beer can," says Dr James Friend, an ultrasonics researcher at Monash University in Victoria, Australia.

But that's where the good news ends. Real-world sonic tools are short-ranged — thousandths of a millimetre. A sonic screwdriver that could work over tens of metres, like the Doctor's, would need a huge power source, unlikely to fit in even Fourth Doctor Tom Baker's ample coat pocket. You definitely won't be able to buy one in B&Q any time soon.


Scientists worked out in the 1980s how to build a time machine using a wormhole - a short space-time tunnel linking distant regions of the Universe, not unlike the time vortex the Tardis uses onscreen


The Tardis materialises and dematerialises, teleporting from place to place. In 2004, physicists in the US and Austria succeeded in teleporting atoms across their lab in a similar way


This was the Tardis's camouflage system, before it got stuck as a Police Box. The University of Tokyo has developed similar cloaks for people, onto which images are projected to give the illusion of invisibility


What are the medical benefits of a 'binary vascular system'?

The Doctor has what the Who writers call a 'binary vascular system' - two hearts. In a way, we humans have two hearts as well. Or rather, one heart made up of two pumps, each serving one of two distinct circulatory systems in the body. The pulmonary system passes blood through the lungs in order to oxygenate it, and is driven by the heart's right side. The systemic circulation, served by the heart's left side, then takes the freshly oxygenated blood and pumps it around the body.

If either of these systems were served by more than one heart, the beats would need to be carefully timed. But it could be worth doing. The systemic circulation comprises a staggering 96,560km of blood vessels - enough to circle the Earth more than twice. Forcing blood around this network with just one heart requires a huge force with each beat, making the peak pressure very high. But if the beats of a second heart could fall in between the beats of the first, the peak pressure could be lower, placing less stress on the vessels.

More likely, though, the systemic circulation would be divided into subsystems, each serving a distinct part of the body and each driven by a heart of its own. This is the strategy adopted by the real-world hagfish, an ocean-going parasite that has five hearts - one for the brain, one for the gill pouches, one for the internal organs and two for the tail.


Technological Time Lord treats


The flying car of Third Doctor, Jon Pertwee, the Whomobile appeared in Invasion of the Dinosaurs and Planet of the Spiders. Moller International is soon to market its M400 Skycar a 4-seater, car-sized aircraft with a cruising speed of 275mph (443km/h)


The nanogenes in the 2005 series were an army of microscopic medical robots that swim through the body healing injuries. Technologist Dr Robert Freitas has designed similar devices. When built (sometime in the next 10-100 years), they'll heal a cut in about a minute


The Doctor's psychic paper was a card that shows whatever the person viewing it expects to see - say, a party invite. Reading and displaying people's thoughts is possible but, alas, requires an fMRI (Functional Magnetic Resonance Imaging) scanner the size of a small room


Christopher Eccleston's Ninth Doctor rigs his assistant Rose's mobile phone so she can call home from the year 5 billion AD. Physicists say there could exist time-travelling particles called 'tachyons' on which a signal could be piggybacked into the past


This was Captain Jack Harkness's weapon of choice. Sonic weapons are now being deployed on US Navy ships in Iraq. Its Long Range Acoustic Devices (LRADs) inflict extreme pain on enemy crews at distances of up to 600m "The Tardis, when working properly, is capable of many amazing things. Not unlike myself" -- The Sixth Doctor, Attack of the Cybermen


Used to provide nourishment for the Tardis's crew. NASA's Institute for Advanced Concepts is designing similar machines to produce foods that will keep astronauts' spirits up on journeys


Dr Chris Van den Broeck has shown how a large-volume space can be enclosed by a low-area surface. It's the 3D analogue of a 2D rubber sheet with a

— lobe attached - the large area of the lobe is surrounded by the small circumference of the neck connecting it to the sheet. Scaling up to 3D gives a large volume enclosed by a small area


The reality behind Doctor Who's planets


First Doctor William Hartnell visits the planet Marinus, which has oceans of acid. Venus has clouds of acid in its atmosphere, but a surface temperature of 482°C. If Venus cooled enough for the clouds to condense into droplets, acid could rain into oceans


The planet Voga in Revenge of the Cybermen was made entirely of gold. This may be possible, says Oxford University astrophysicist Prof Fred Taylor - clouds of silver can form around Jupiter and could condense, and perhaps this is true of gold too


The Doctor's homeworld of Gallifrey was destroyed by the Daleks. But blowing up a planet takes energy. The largest nuclear weapons are equivalent to 50 million tons of TNT. And you'd need a million billion of these to do for an Earth-like world


On the jungle world Spiridon, Third Doctor Jon Pertwee encountered volcanoes spewing ice and slush. Just such 'cryovolcanism' was discovered by the Voyager 2 spacecraft on Neptune's moon Triton when it flew by in 1989


Could a whole planet ever be used as a jail, as with the Time Lord prison world Shada? There are parallels with Britain's history of transporting criminals to Australia, though the cost of launching into space is, for now, prohibitive


Why does the Doctor need an assistant?

Aficionados agree that as of 2005, the Doctor has had 29 travelling companions. He's only ever appeared once without one: 1976's The Deadly Assassin.

Dr Angela Carter, an occupational psychologist at the University of Sheffield, believes that people (and presumably Time Lords too) crave companionship because they are social animals. We've evolved for millions of years operating as part of a pack - hunting and gathering in groups. But we also need others to help us clarify our identity. "I learn from my peers what I do in my work, and in the same way we learn from our companions what our role is in life," she says.

That said, Doctor Who's producers have another reason for casting assistants: viewing figures. "Men talk quite extensively about their early fantasies of latching on to one of the Doctor's assistants," says Dr Petra Boynton, a sex and relationship psychologist at University College London. "Tom Baker's assistant Leela seems to come up a lot."


Your Sony Aibo has a little way to come yet

When the Doctor's robot dog K-9 made his debut in 1977, few would have predicted that real robot dogs would be available to keep as pets just a little over 20 years later. But in 1999, Sony launched its Aibo electronic dogs. The artificially intelligent pets can see, hear and touch and make decisions of their own accord.

They've been a runaway success. In 2000, Prof Kevin Warwick, of the University of Reading, carried out an experiment where for a week he replaced a family's real dog with an Aibo. "At the end of the week we asked the two kids in the family if they now wanted their original dog back or if they wanted to keep the Aibo," says Warwick. "We were amazed when they said they wanted to keep Aibo."

As yet, Aibo's faculties are no match for K-9's, but artificial intelligence expert Steve Grand, of Cyberlife Research, is optimistic that it will one day be possible to mimic the way real brains work using technology. How soon? "Any time between a week and a century from now," he says.


Future cyborgs, and why we won't be on their Christmas list

The Cybermen were created in 1966 by the show's science advisor Dr Kit Pedler, of University College London. Pedler was fascinated by a revolution sweeping medicine: transplant surgery. He envisaged the Cybermen as a race that had taken this to the extreme, replacing nearly all their original body parts - in this case with mechanical and electronic components. Professor Kevin Warwick, a cyberneticist at the University of Reading, says it's highly likely such a race would be hostile. He thinks an advanced cyborg, used to communicating via high-speed data transfer, is going to pay little attention when a human starts making the primitive noises we call speech. To them we are a lower life form. "I can quite see future cyborgs, and the Cybermen of Doctor Who, not particularly wanting to be friends with humans," he says. So it's perhaps surprising that researchers have made as much progress building real cyborgs as they have.


Real-world cochlear implants hook up a microphone directly to the auditory nerve, giving back hearing to patients who have lost this sense completely


Cybernetics linking the brain directly to electronic hardware have already allowed doctors in Massachusetts to give a quadriplegic patient control over his computer by the power of thought alone


A surgeon at the University of Pittsburgh believes he has developed an implantable artificial lung to help sufferers of lung diseases like emphysema and cystic fibrosis


Modern materials such as carbon fibre, Kevlar and titanium are letting researchers build high-functioning prosthetic limbs that are easy to use. The muscle in the patient's stump 'talks' to the electronics controlling the limb


In 2001, a frostbite victim who had lost all his fingers and thumbs during a mountain expedition received an artificial hand that gave him enough dexterity to be able to write again


Biotech company Abiomed now produces a mechanical heart made from plastic and titanium. It weighs 1kg and can pump 10 litres of blood per minute. An 'inductive plate' allows the batteries to be recharged without penetrating the patient's skin


Preparing for the end (if you're a hydra)

When the Daleks finally get the better of the Doctor, rather than dying, every cell in his body regenerates. He gains a new life - and a new appearance.

Regeneration is a concept that's already familiar to biologists. Go down to the pond at the bottom of your garden and fish out a freshwater hydra. These cylindrical lifeforms, relatives of the sea anemone and measuring anything between 1mm and 20mm in length, are able to regrow damaged body parts. "If you were so unpleasant to a hydra as to cut it up into little pieces, you wouldn't actually be doing it a bad turn," says Professor Tom Kirkwood, a gerontologist at the University of Newcastle. "Each of the pieces would soon regenerate into a new organism."

When an embryo is created, its cells are in an 'undifferentiated' state. But as it grows and develops, the cells differentiate into particular tissue types - skin, organs and so on. During regeneration, some of the cells are able to return to their undifferentiated state and then re-differentiate into the types of tissue needed to repair the damage. The process is called 'morphallaxis' and normally takes 3-4 days. The regenerated hydras are smaller, but fully functional. Morphallaxis couldn't work in humans because our cells are too strongly differentiated. But for Time Lords - who knows?


Genetics + tank technology + antigravity = cosmic domination

Pepper pots brandishing sink plungers aren't the most likely physical form for the dominant evil in the Universe. But as master villains in Doctor Who their success has been legendary. At one point producers were even issued with the diktat that every series must have a Dalek adventure, since they were such a ratings winner.

The Daleks are cyborgs - genetically engineered superbeings inside tank-like armoured 'travel machines'. They were created by Davros, chief scientist of the Kaled race. For many years, the Kaleds had been fighting a nuclear and biochemical war against the Thals. Davros had taken genetic mutants created in the war and selectively bred them to create the perfect soldier.

Selective breeding is a familiar idea. "What you're doing is increasing the probability of getting an intelligent child from say 1 in 100 to 1 in 3," says Professor Denis Murphy, a biotechnologist at the University of Glamorgan. "The Daleks would probably then grow up the three kids and only one would be really intelligent, so they'd get rid of the other two." It's much the same process that's discussed today for preventing heritable diseases such as Huntingdon's and cystic fibrosis from being passed to offspring. Embryos produced by a couple are screened, and only those that are free from any disease-causing genetic mutations are brought to full term.

As well as super-soldiers, this procedure could in principle be used to create 'designer babies' that'll grow into anything from ultimate athletes to blue-eyed blondes.


The force field used by the Daleks is reminiscent of the 'electric armour' developed by the UK Ministry of Defence, which can vaporise rocket-propelled grenades fired at tanks


Infantry-level beam weapons are still some years away, although experts predict that by 2010 truck-mounted units could be in service


A number of blind patients around the world now have rudimentary sight thanks to the Dobelle artificial vision system, which links a camera chip directly into the brain's visual cortex


In 1996, a researcher in Finland claimed to have built an antigravity machine that reduced the weight of objects above a spinning superconducting disk. His claim has yet to be verified


Daleks are clad in 'bonded polycarbide armour'. The 'poly' prefix suggests this is some kind of plastic. Indeed, the US military is experimenting with rubbery plastic vehicle armour that dissipates the force of explosions


A lifeform selectively bred from the victims of nuclear and biochemical warfare. Selective breeding of 'designer babies' is possible, but hotly debated


Are we set up to cope if a Dalek battle fleet arrived tomorrow?

Aliens assaulting Earth is the premise for many a good Who romp. But one researcher thinks we should watch the skies for real. "In a Universe full of life, some extraterrestrials are likely to be friendly, some hostile," says Nick Pope, who has investigated UFOs for the UK Ministry of Defence.

In Doctor Who, Earth is guarded by the United Nations Intelligence Taskforce (UNIT). But Pope knows of no similar organisation in reality. "I used to run the British Government's UFO Project, but we weren't set up along the lines of UNIT," he says.

The MOD project sought to establish the reality (or not) of the UFO phenomenon by interviewing witnesses, studying radar tapes, analysing photographs and trying to correlate UFO sightings with known objects and phenomena. Considering the military response to an alien threat was not part of Pope's brief.


Could life be based on 'organic calcium'?

The Slitheen are a family of aliens with a taste for human meat, first encountered by Christopher Eccleston's Ninth Doctor. They are based on the element calcium - rather than carbon, which forms the base for biochemistry on Earth. Carbon is a very good element for life because it's 'tetravalent'. That means each atom is able to form up to four strong 'covalent' bonds with other atoms and molecules. That lets nature build thousands of complex organic molecules from it. Calcium, on the other hand, is only bivalent. It can only form two covalent bonds, so all you can build are basic, line-like molecules. "It would be impossible, therefore, for calcium to form semi-rigid open structures like protein or DNA," says Dr Matthew Genge, an astrobiologist at Imperial College London. So calcium-based life is unlikely.


How realistic are the Who aliens?


Walking shop dummies, animated from 'living plastic' - realistic? Actually, yes. Prof Tony Ryan at the University of Sheffield is building what he calls 'squidgy robots', machines made from plastic artificial muscles that can be controlled electronically


These reptiles were meant to be from Earth's Silurian period (440 million years ago). But that's before dinosaurs evolved. Realising their mistake, the writers changed this to the Eocene period (34-56 mya). But that's still wrong - it's after dinosaurs died out


In the year 5 billion AD, Lady Cassandra is the last pure human being. She's had so much plastic surgery that all that's left is a brain in a jar and a piece of skin stretched over a frame which needs constant moisturising. Unlikely, say experts!


These Martians towered over human beings. Mars's gravity is about one-third of Earth's, so creatures there would weigh only a third what they do here. With less weight to support they would indeed grow much taller


A short, squat, warlike race, Sontarans reproduce by cloning themselves. This certainly works. Since Dolly the sheep famously became the world's first cloned mammal in 1996, researchers have copied a multitude of beasts, from mice to horses

WIN! The Science of Doctor Who

Icon Books have agreed to stump up 10 signed copies of The Science of Doctor Who. For your chance to win, simply tell us the name of the 1960s Doctor Who science advisor who invented the Cybermen. Entry details on p70

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