"Welcome to Stargate Command." "I'm Amanda Tapping and I play Lieutenant Colonel Samantha Carter." "Samantha is chief scientist and leader of an elite team called SG-1." "SG-1's mission is to travel through an amazing device called a Stargate to planets on the far reaches of the galaxy." "There they fight unspeakably evil aliens, commune with higher beings, and use fantastic technology." "Oh... and of course they often save humanity and the galaxy from complete annihilation." "On the show "Stargate SG-1", we take pride in pushing science fiction to the limits of human imagination." "alien parasites, parallel universes, time travel, wormholes through space and time." "Some might say it's just fantasy, but amazingly, it doesn't mean it's not true." "In the next hour, we're going on a different journey not just through the set of Stargate but also into the world of real science to see that what seems like crazy sci-fi fantasies might actually be true." "Transcript:" "Callie Sullivan" "Science fiction and science seem to be getting closer and closer all the time, and I think there's a good reason for that." "They're both about the human imagination;" "they're both about asking "What if?" questions;" "they're both about trying to understand our place in a very complex universe." "We read the newspaper and current science magazines, watch the news, look for things that are sort of interesting, hot button issues that often come up and will inspire us." "We read up on black holes, we read Stephen Hawking and most of it goes over my head but the fun part of what you read is, "Oh, I can use that, that'll be fun for the story."" "Science fiction takes the narrative route, it's story telling, but the people writing the stories have to solve the same kind of problems that the scientists do, and in many cases I think the science fiction writers are coming closer to the truth than the scientists." "It's so grounded in true scientific terminology and things that can actually happen in the universe that, for the people that are more knowledgeable and don't just watch it for the fantasy and escapism, can find their hook into it in the actual science of it." "Science is great, but in fiction you still need a battle between good and evil." "From the very beginning of the series, SG-1 have had to face humanity's nemesis, a race of aliens so evil, they won't rest 'til they've enslaved the entire galaxy." "They have filled our nightmares, they have made us take terrible risks." "At times we thought we had lost the battle." "They are... the Goa'uld." "Now the idea of this creature burrowing inside your body, taking over your brain and dominating your behaviour is one of the scariest things that occurred in "Stargate"." "It happened to my character Samantha early on in the show, and let me tell you, she hated it." "Sci-fi writers have come up with some pretty evil aliens over the years, but the Goa'uld must certainly rank as one of the nastiest." "In true sci-fi style, the snake-like parasites, the Goa'uld, took over the minds of their army of warrior slaves, the Jaffa, and then set about trying to rule the galaxy." "But one brave Jaffa slave, Teal'c, saw the truth and broke free from the parasites' control." "He joined up with us, the team from Stargate, and the battle for the universe began." "Exciting stuff, eh?" "This parasitical race of beings could only survive in a host body, so they actually went to ancient Egypt and acquired a bunch of human hosts, inhabited their bodies and controlled them until they were mature enough to take on a permanent host, so basically a Jaffa is an incubator for the larval form of the Goa'uld." "It's not something you can shoot or run away from, it's inside you and it's controlling you, and there's this icky factor to it, you know, it's gross and they're pretty disgusting," "these snaky things that sort of burrow their way into the back of your head." "As an intelligent and totally evil parasite, the Goa'uld are terrifying adversaries, but we don't have to look far on our own planet to find creatures equally as horrifying." "If you were a visitor from outer space and came to Earth and really studied its living organisms objectively, and then went back home, what would you say to the folks back home?" ""Most of what's living down there is a parasite."" "Professor Janovy is the world's leading expert on a very creepy kind of creature." "This is Monesia expansa, a tapeworm from sheep." "At the University of Nebraska, he runs one of the world's most unusual museums, with over one hundred and fifty thousand stomach-churning exhibits." "These are Fasciloides magna which came out of the liver of a white-tailed deer." "Each of the creatures in his museum succeeds by sucking the very life force from another living creature." "This is Ascaris lumbercoides, or roundworms." "These worms infect about one ou of every four people on Earth." "That's the one schoolkids get, remember?" "You see, we humans are a perfect snug and warm place for parasites." "This is Taenia saginata, the beef tapeworm, that human beings get from eating uncooked beef." "I think if we laid that out on a table and measured it, it would probably be fifteen or twenty feet long, easily, and humans can have any number of these things." "Disgusting parasites like this are nature's vampires." "They take advantage of other creatures using their body as a free lunch." "They are ruthless, taking what they need, reproducing, and then moving on." "And revoltingly, we humans are the perfect place for them to live." "Yuck!" "There are a big variety of parasites that infect human beings:" "lice, ticks, flukes that live in the bloodstream." "There are large nemetodes that live in your intestines, there are parasites that live in your mouth." "Some of them cause very destructive erosion of the skin, others are very damaging to the spleen and to the liver." "There are at least two hundred species that some of us, at least, have been infected with over the years." "What makes the Goa'uld so particularly scary is that they totally take over their human host." "But, you guessed it, it turns out this crazy science fiction fantasy is actually based on real science." "There are many reported cases in nature of parasites being able to change the behaviour of their hosts." "These are pictures of Dicrocoelium dendriticum." "They live part of their life cycle within an ant's body and brain." "It's a parasite, just like the Goa'uld, only a bit smaller." "Its larva digs its way to the ant's brain where it perverts the ant's natural instincts, so instead of the ant cowering safely in the undergrowth like any good ant would, it suddenly becomes compelled to self-destruct by climbing to the top of a blade of grass" "where passing sheep will eat it." "Once in the sheep, the parasit can continue its revolting life cycle." "Oh, but it doesn't just happen in ants, oh no!" "Hold onto your stomachs, because scientists suggest that some parasites can actually make us humans do stuff we can't control." "For example, the pig tapeworm that human beings get from eating uncooked pork, those worms form cysts in various parts of the body, including the brain, and as a result we have all kinds of behavioural changes, dizziness, lethargy," "sometimes a loss of vision, so this is another case in which our behaviour is altered by a parasite." "So if tapeworms can change our behaviour and make us dizzy and tired, is it possible that an alien parasite like the Goa'uld could control our minds completely?" "The evolutionary rules say that there has to be a reason for it, so maybe infection with a certain kind of tapeworm might make us become evil or criminal." "If there's a reason that has to do with... reproductive success, then sure, why not?" "Scared yet?" "You should be, because as it turns out, Professor Janovy believes we might not be the dominant creatures on Earth." "It's the parasites." "They infect everything, they are more diverse, they are successful in occupying environments that we would consider not necessarily places to live." "In some cases they control populations." "It's the most successful way of life on Earth." "Does she please you my love?" "This Stargate forms the battleground in our struggle between the powers of good and the powers of evil." "On our side at Stargate Command, helping us are various aliens like the Asgard, the Tok'Ra, and humans all around the galaxy." "Against us are the terrifying parasites the Goa'uld, and the unstoppable and insatiable Replicators." "At first, we at the SGC fought them with our low-tech Earth guns, but pretty soon, we discovered these." "This is a staff weapon, and this is a zat gun." "One blast and your enemy is stunned, two and they die." "Now you may think this is pure science fiction, but it turns out that the truth is much more strange." "What you're seeing here is the taser." "It's a hand-held gun that brings criminals to their knees by blasting them with a fierce jolt of fifty thousand volts of electricity." "The amazing thing is that the taser can knock down a suspect without killing or even harming them." "But the US government are secretly developing something far more powerful." "It's called the Active Denial System." "This classified new weapon works by emitting a beam of microwaves, like the ones you get in your microwave oven but much more concentrated." "It is, so the experts say, a perfect ray gun." "So with ray gun weapons that stun already in development, are guns that can actually disintegrate a person too far-fetched?" "In order to vaporise you, I'd have to heat you up to about a hundred million degrees, and the energy required to do that is immense, just literally immense, so it's hard to imagine in a hand-held device" "that you'd be able to do those sorts of things." "Directed energy weapons can be useful in certain contexts, they can burn things, they can destroy electronics, they can blind people, that sort of thing." "After the break, I'll be showing you more of the Stargate set, and we'll come face to face with one of the most fierce and terrifying of all of mankind's adversaries, and finding out whether their Earth-based relatives should be loved," "or feared." "The time has come to meet the Replicators." "Not that I wanna show off or anything, but "Stargate" is currently one of the longest-running science fiction series in the world, watched by nearly twenty million people in over eighty countries." "Not bad, eh?" "It's amazing that people enjoy the show, because really the heroes of the show ar a bunch of screw-ups who are always causing, you know, horrible problems for themselves and everyone else." "I guess it's the fact that they occasionally make up for it or get out of those problems that keep people coming back." "The series is shot in over nine sound stages in Vancouver, Canada." "The show employs a crew and cast numbering more than five hundred, and its punishing schedule turns out one episode every seven days." "That's pretty fast, but you wouldn't know it by the atmosphere here on set." "As you see, we don't take ourselves very seriously and there's none of that... you know," "TV star attitude." "It won't be tolerated at all." "If you've got a joke, action has to wait, you know, and so it's always about laughter first." "At the heart of all the adventures Samantha Carter and SG-1 get involved in, and what makes this show particularly unique is this, the Stargate itself." "It's an amazing device inscribed with unusual symbols." "It looks beautiful, but what makes it truly amazing is that it's a gateway through time and space." ""Stargate" imagines that there are thousands, if not more, devices, ring-shaped devices not unlike the one behind me all over the galaxy by which you can travel from planet to planet simply by stepping through it" "and it takes you instantaneously from one planet to another." "In fact," "I think the Stargate is one of the reasons the show's been running for so long, it's because the Stargate itself is a terrific device for storytelling." "And the fact of the matter is, this is a, you know, it's a great prop." "I mean, it's a doorway, because essentially it's, every week, it's "Where are we gonna go?"" "You know, it's like getting into a rollercoaster with your best friends, and you wanna take that ride this week." "In the series, this Stargate is one of thousands throughout the galaxy created by a mysterious and powerful ancient civilisation." "You can cross limitless space in the blink o an eye just by going through one Gate and out of another." "It really is instant interplanetary travel." "So how does it work?" "As Samantha Carter is always trying to explain to the usually clueless Jack O'Neill, a Stargate works by creating an artificial wormhole through the space time continuum." "That's a tunnel in time and space through which we can travel, covering huge distances in just a short moment." "So is this a flight of fantasy, or a genuine piece of contemporary science?" "Well, the truth may shock you." "Lawrence Krauss is a professor of physics and astronomy and leading expert on Einstein's theory of relativity." "Some of the implications of Einstein's famous theory are truly mind-blowing." "One of them is that empty space can bend." "Now, I know that's a really hard idea to get your head around, but it's true." "Emptiness can be made to curve." "You see, Einstein told us that mass or energy curve space." "And if I take this bowling ball here, in this two-dimensional universe you can see that when I put it down, it literally curves the space around us, and that allows all sorts of interesting things to happen." "So let's get this straight:" "Einstein's theory says that something really big, something with a lot of gravity like a star or a giant planet, can literally bend space, and if it's big enough, it can really bend it," "a lot." "Now, take this pole here, and say this is your universe and you're an ant living at this end." "Well, it's a long way from here to there that is, unless the space in which you live is curved." "Well, you might think you're very close now, you could just sort of jump across, but you can't, because there's no space there." "This is your space and you still have to walk all the way around unless you bring them closer together and they actually touch." "That changes the topology of space." "That's your shortcut." "That's a wormhole." "So if we were smart, we could theoretically bend space so much, it actually comes right back on itself." "You think that's crazy watch this!" "So here we are, Amanda, magically transported." "There's space all around us, with Stargate Command here, and the moon way over there, two hundred and fifty thousand miles away, pretty far." "But if we curve space around Stargate Command, and round the moon, and eventually create a tunnel that touches, create a little hole, then we have a tunnel, a wormhole, and the distance between Stargate Command and the moon" "is very small through the tunnel." "In fact, if you look through the tunnel there, there's the moon just on the other side." "See it?" "Pretty sexy...?" "Mathematically they exist, they're consistent with the laws of physics, but you've still got to make them happen and we don't have very good technology for dealing with wormholes." "Another problem with wormholes is, they tend to be unstable, they collapse." "If you just build them and leave them, they fall apart again." "The gravitational fields would be so strong at either end of the wormhole that each end will collapse into a black hole out of which nothing could escape." "But even if scientists could succeed in holding a black hole open, passing through it would definitely not be for the squeamish." "It could actually be really stressful going through because space and time would be very very heavily curved, enormous gravitational fields." "Unless you're careful, you could be shredded." "Scientists have imagined that a wormhole would probably look something like a floating crystal ball." "If you could see into it at all, you might see an inkling of what's on the other side, and this is roughly speaking what the producers of Stargate have made their Gate look like." "It'd be a bit like a mirror." "When you look in the mirror, you see another world." "When you walk round the back of the mirror, the other world isn't there, but if you walked through the mirror like Alice, you're suddenly in the other world." "You can actually see the fluctuations in the event horizon." "We have all sorts of reasons to believe that making one would be very difficult, but their existence is consistent with the known laws of physics." "The Stargate has opened up a whole new world of "save the universe" style adventures for us at SG-1, and I have to say, we've met some terrifying and weird enemies." "This is my lab." "It's here that I first realised that these small pieces of alien technology formed Earth's most serious threat." "Although humanity's fiercest and most memorable adversary are the parasitic Goa'uld, early on in SG-1's adventures we found ourselves up against what seemed like an unstoppable enemy." "We thought we beat them once, but soon they were back bigger, better and bent on universal domination." "They are... the Replicators." "The Replicators are virtually unstoppable." "They devour anything they come across and use that material to replicate themselves, making themselves stronger and more powerful as they go." "They can also assume different shapes, from spider-like creatures right through to spaceships and even humans." "In Series 8, they even made a Replicator version of me." "And terrifyingly, the Replicators communicate with each other through a common consciousness." "They have this greater capability because they were all able to communicate with each other, and they looked cool and they were scary and we could shoot them and not feel guilty about it because they were just machines." "It was born out of a desire to create another villain other than the Goa'uld but that were shark-like in their killing potential." "They couldn't really be reasoned with, and so were deadly from that perspective." "Of course, here on Earth, scientists are also working on our own Replicator-like robots." "These ones at the University of South Florida can talk to each other and think together." "But thankfully, they're designed to help us, not kill us." "In fact, scientists have designed robots that can help in the dangerous business of looking for survivors in the aftermath of a disaster." "They are continually in use by the emergency services, and even saw action following 9/11." "And a bit like the Replicators, they are highly mobile and have a sophisticated communication network perfect for search and rescue." "For search and rescue, there are really three types of robots that you would be using." "You've got ground robots which can go into the interior of the rubble and places that people and dogs can't go." "You also have aerial vehicles which can be incredibly useful, particularly if you've got a hurricane or earthquake, where you've got a large geographically distributed disaster." "And then don't forget about water." "A lot of our cities are based around water and you wanna see if there's any leaks or cracks or if something's fixing to break and cause a collapse of a bridge." "A lot of times right now, with the state of technology, the human is the smarter one, but that's beginning to change, 'cause robots working together is something that's coming soon." "They're starting to give information to you." "At the same time, they're relaying information to their other friends, their other peer robots, saying," ""Hey, can you see this?" "Slow down, because this is where we're seeing survivors."" "Ah, I see fire." "In the meantime, this information will be relayed to aerial vehicles." "Those may be smart enough to say," ""Oh, but so much is happening." "Let's call our other friend robot he's not doing much over there." "Come over here and work in this area for us."" "So imagine this whole web where the right information's getting to the right people, or the right robot, at the right time." "Scientists at NASA are pushing the idea of groups of robots working together even further." "They've developed a robot called the Twelvetet." "On its own, it can move across the ground by sort of wiggling, crawling and falling." "But what's really cool is when they put a whole group of them together." "They join up and can crawl over really rough terrain, cross wide gaps, and even climb walls." "And they think as one." "Each robot is autonomous, but their overall action is that of a single organism." "Remind you of anyone?" "Another of the Replicators' most terrifying characteristics is their unstoppable ability to learn." "Wherever they go, they become more intelligent and even more powerful." "At Reading University, Professor Kevin Warwick is revolutionising robot technology by studying how they think and learn." "Warwick's team have been experimenting on what very basic robots do when they react with each other and their environment." "Each of the robots has, I guess, only about fifty to a hundred brain cells, so it's equivalent to basic slugs and snails, so relatively they're quite simple but we can still look at how they learn." "His robots were not told what to do." "They had to learn for themselves." "What they have is a goal, and that is:" "move forwards, but don't bump into anything, and hence the robots come up with different behaviours, different characteristics." ""Do I move to the left?" "Do I move backwards?" "Do I pirouette?"" "And the robots ended up doing things Warwick's team had never dreamed of." "You get good robots, you get bad robots." "It depends on what their learning experience is like." "We have had in one case a suicidal robot!" "Everything it did was wrong in the end it stopped doing anything!" "Only one time we've ever achieved that, but these extreme cases do happen." "Far from being things that you can programme and they will always do what you want them to do, learning robots almost surely will do what they want to do." "For Kevin Warwick, this means only one thing:" "a robot which learns for itself could end up having ideas of its own and they might not be that nice." "Machine intelligence has different values, different ethics to human intelligence." "If it's learning and deciding for itself who are its friends, who are its enemies, it's almost surely gonna be very dangerous for humans." "And me standing there saying, "Aha!" "You're not conscious like I am, therefore you can't kill me,"" "well, it would just blow my head off and that's it!" "Sounds totally Stargate, doesn't it?" "And he's taken the idea so seriously that he's been thinking about an even more sci-fi way to deal with it." "The only possibility I can see is to upgrade what we are as humans, to make us into cyborgs, essentially saying, "OK, if machines are gonna be more intelligent than humans, let's join them." "Let's become part machines ourselves."" "And if that sounds like total fantasy, then get this:" "Professor Warwick had a microchip surgically implanted into the main nerve in his left wrist as part of a cyborg experiment in 2002." "His robots were then able to interact directly with his nervous system." "He could control devices like a robot hand, and a wheelchair, by thought alone." "That's left... and right." " Are you enjoying that, Kevin?" " Oh, it's excellent, yeah!" "And the chip allowed information to flow the other way too from his equipment directly into his brain." "In one experiment, he attached radar sensors to a baseball cap that fed signals into his mind." "Then, blindfolded, he found that he was able to see like a bat." "It was a new feeling." "It was a new sensation." "It wasn't as though it felt like somebody was touching me;" "it simply felt "something is close, on the right or the left."" "Listen to me talking to you." "Come over this way." "Keep listening to me." "Let's go back to the other way." "Warwick's next sci-fi like experiment will be to implant a chip right into the middle of his brain." "This way, this way." "Pay attention." "And where that takes him as part-robot, part-human cyborg is anybody's guess." "D'you recognise me?" "I am your terminator." "I would love to have some of the memory capabilities, some of the abilities to communicate just by thought, even just having some extra dimensions in my brain to think not in this limited human form of three dimensions, but to think in five dimensions." "Wow, wouldn't that be fantastic?" "The whole world would seem as a different place to me." "I can't wait for it." "After the break, we'll take on the biggest scientific mystery of them all." "Time travel?" "It seems difficult to believe." "Stargate has been on the air for over eight years, and has become one of the most popular science fiction shows in the world." "With its stunning visual effects, exciting storylines and even if I do say it myself great characters, it has galvanised audiences." "But the series has made a point of not just looking at the science fiction of battling aliens, though." " What?" " They're not multiplying, they're replicating." "What's the difference?" "Living organisms multiply." "Machines replicate." "Machines inside the body?" "How is that possible?" "When I was at the Pentagon, I worked for a year with a group that studied nanotechnology." "We were looking at it for a lot of different uses." "One of them was medicine." "Yes, you've guessed it." "At the University of Michigan, Doctor James Baker and his team have combined medicine, engineering and computer technology to make nanoparticles." "These tiny particles are so small, one hundred thousand could fit into the smallest cell in the human body." "And believe me, at that size, they are capable of the most incredible things." "We're actually doing surgery on the molecular level, altering single molecules rather than going in and grossly cutting things out." "So this is a whole new level of, well sort of, human engineering that can occur." "His team can engineer these particles so precisely that when they get in the body, they act like tiny robot doctors." "They can locate unhealthy cells and act on them with incredibly specific treatments." "His team have had some spectacular results." "For example, if you want to deliver a drug to a cancer cell, the nanoparticle first would find the cancer cells, it would identify them with an imaging model so you can actually see the cancer." "It would then tell you what the genetic abnormalities are in the cancer and allow you to activate a drug specific for the abnormality for that cancer." "And that way you could get the cancer killed without harming the individual." "So that's our real goal to change cancer to a treatable disease." "And there seems to be no limit to what nanoparticles can do." "We then could load things that would fluoresce, under certain conditions, into your bloodstream, so for example if you had the 'flu, we'd know that you had a viral infection maybe before you could even show the symptoms." "I think what nanotechnology could do is move us from the point of treating disease to truly the point of preventing disease." "I think nanotechnology has the potential to fundamentally alter medical care." "From the very beginning, the producers of "Stargate" have felt very strongly about the design and feel of the series, from the look of the military institution that is the SGC here, right through to the incredible detail on the various aliens that we've encountered." "From the warrior Jaffa, the parasitical Goa'uld, the friendly Una, and the all-powerful Asgard, we've met a bewildering variety of aliens." "Let's talk." "There are all kinds of different ways to go with aliens, and so we have a very talented group of artists and designers who work on the show and we basically, you know, go to them and say," ""Draw us some pictures, and come up with something that looks cool,"" "and then it becomes a question of balancing costs and design." "But if you want a character that's going to be funny and interact with your regular actors on an ongoing basis, then it's always best to have an actor there." "It's the best way to get a character to come out of your alien." "For some of the actors, playing an alien was second nature." "I've always kind of been an oddball, you know, kind of in every phase of my life, so it just kind of fit me that I was destined to play an alien." "I found that the best thing that worked for Teal'c is just to have a very very rough idea of what was gonna go on during the episode." "I wasn't ever interested in what they were talking about." "I would just have my own take on everything that was going on, and to do that, I really would not read scripts." "I would never read any lines - including my own!" " which some directors didn't really like!" "But I found that my level of unpreparedness served me well." "On "Stargate" we get inspiration for our aliens from the natural world, and from our worst nightmares." "But some, like the Asgard, are really sweet and kind." "They save humanity all the time." "So just how far-fetched are they?" "Asgards are too close to human to be believable as aliens who have simply come from a distant planet and have no connection with us." "If we actually found aliens like that, then the scientific view would be maybe we shared a common ancestor with them, say two million years ago." "It would take about two million years to evolve to something that different from us." "OK, but what might real aliens look like?" "Professor Ian Stewart at the University of Warwick was asked by the Science Museum in London to answer just that." "If you're gonna do this scientifically, you can't just say, "Ooh!" "Let's have seventeen foot creatures with blue skins and big horns."" "You have to start with the environment in which they evolved." "For example, here on Earth we have quite powerful gravity and very solid ground, so many creatures have adapted by having some sort of rigid skeleton to keep their bodies upright." "But on another planet, life might have a very different shape." "Take Jupiter, for instance, which has much more gravity than us, and is a huge ball of gas with no solid ground." "As there's nothing to stand on, creatures there probably wouldn't have skeletons at all." "In fact, they'd be more likely to fly or float, and their whole shape and behaviour would follow from that." "So we think you'd get something more like a sort of balloon creature which floats in the atmosphere, and we came up with several types of balloon creature and called them "frisbees" and "flashers" and "darts" and "delphins"." "The frisbees are herds of enormous circular, slowly rotating creatures, like a giant pancake, probably the size of a football field, really big, 'cause there's a lot of room on a gas giant planet." "And then we realised on the frisbees you could get parasites, so we came up with little dog-like creatures but they have a blue light on top and they use the blue light to signal to potential mates when it's mating season," "and they leap from one frisbee to another to secure mates." "The delphins were a very interesting creature that we came up with." "We realised that skeletons would not really be made of bone like they are here." "It'd be very surprising if on a gas giant you got bone, so we decided that what you might get is kind of a series of hollow tubes which are activated by hydraulic pressure, like the brakes on your car." "And then we were looking for fast predators, and the darts live in the lower atmosphere and they've got four fins at right angles like the tail end of a dart, and a very sharp front end," "and they hunt in packs and come up to the upper atmosphere and they hunt frisbees." "With trillions of vastly different planets and worlds out there in the universe, who knows what bizarre shapes aliens may turn out to be?" "Probably much weirder than the Goa'uld or the Asgard." "However, for many scientists, what is not in doubt is whether aliens actually exist." "The universe is so big, there are so many stars and, we now know, so many planets that I would be absolutely astonished if there are no intelligent aliens out there." "If we're the only one, it's crazy." "That life may exist on other planets at all is fairly mind-boggling, but that we might be able to hazard a guess about its shape and behaviour pushes the boundaries of what we assume is science but not as much as our last, most controversial thought:" "how far-fetched is it to think that we could pass through time, as well as space?" "Passing backwards and forwards through time is something we've dreamed about for generations." "The chance to see our future and revisit our past has been one of the most exciting ideas in all of fiction." "Guess what?" "It might be possible, thanks once again to Einstein's theory of relativity." "You see, Einstein realised that time doesn't tick along at the same rate for everyone." "He worked out that the faster you move, the more slowly time passes for you." "So imagine if I had an identical twin and I left her here on Earth and got into a sports car and drove into space at, say, ninety nine percent of the speed of light." "As well as feeling slightly car sick, what Einstein said is that, as I get faster, time moves slower, at least for me compared to my sister." "So that when I returned from my journey," "I would have aged normally but my twin would have aged a lot." "In effect, I would have travelled into the future." "And amazingly, this has actually been tested." "One of the first tests was done when we developed atomic clocks which were sensitive enough to be able to tell time differences of a millionth of a second or so, and in that case two atomic clocks were carefully" "synchronised; one was put on a plane that basically went around the world and came back and the two were compared, and indeed they differed by an order of a millionth of a second, exactly as Einstein's theory predicted." "But the real jewel in the time travel crown would be to travel back in time." "That's what fascinates people because we'd all like to go back in time and correct the errors of our youth, or relive them, depending upon our mood." "And surprise, surprise - the science of this turns out not to be too far-fetched." "Physicists have come up with quite a lot of different potential time machines which, according to the laws of physics, would in some sense let you travel back in time." "So spinning the entire universe... rolling the universe up into a cylinder... is a magnetic black hole which makes a lovely time machine which is like a sort of doughnut that traps... the black hole end to and fro very very fast... a very large cylinder of matter which is spinning... spinning black hole... quantum mechanical time machine... so there's an enormous number of potential designs for a time machine." "Going back in time sounds great, but it's actually fraught with problems, many of which we've explored during "Stargate"." "What if I went back in time and accidentally shot myself with a zat gun?" "If I'm dead, who went back in time to shoot me?" "A bewildering time paradox." "Contradictions like this were the backbone of the stories at the end of Series 8." "We saw the tablet." "What tablet?" "Oh, the one you haven't written yet, and put where the Stargate was supposed to be buried." "Supposed to be?" "Confused?" "So were we, and these kind of weird paradoxes have turned most scientists against the idea of backward time travel." "But a solution to these contradictions may lie in science's most bizarre discipline." "Welcome to quantum mechanics, the weird science of atomic particles, and a very very strange answer to the time paradox." "Quantum mechanics is more exotic and strange than any other area of physics, and, for example, at the atomic level, things like electrons are actually doing many things at the same time." "When an electron goes from A to B - unlike a baseball when it travels from one place to another, it takes a clear trajectory - when an electron goes from one place to another, it actually takes many paths at the same time." "That sounds insane but it's actually true and we can test that." "And one way of understanding it is called the Many Worlds Interpretation which suggests that there are many different realities going on at the same time and each time you observe something, you fix it to be in one version of reality, one branch of the quantum mechanical wave function." "And the suggestion is that when you go back in time, you jump to another branch and it's OK if there's a different future because it was gonna have a different future anyway." "Basically, scientists have theorised that there are an infinite number of dimensions, each containing a different possible version of reality." "Well, it sounds like I theoretically, possibly, actually found one." "We explored this idea in several episodes of "Stargate" with alternative Samantha Carters and SG-1 members being central characters in the plot, which certainly has made the series unusual to act in." "And it seems to offer a solution to the paradoxes of time travel." "So if I went back and shot myself, all that would have happened is that the me that existed in one universe is bounced into a universe where I was shot." "No paradox." "Once again, it seems that modern science is at least as strange and unusual as the wildest science fiction." "Science and science fiction are both about possibilities, and it's not surprising when you sometimes find out that science fiction writers and scientists come up with the same answers to those problems." "They're just creative people working." "The only difference is that the science fiction writer can imagine it, but the scientist actually has to build it." "If it isn't happening now, maybe ten years from now the possibility is that we will see the wormhole to travel to another planet," "or creatures like the Replicators, you know, coming out of labs, you know, somewhere in Silicon Valley." "While it is still escapism and using science to have fun, it appeals to a segment of the audience that would like to think that we're sort of on the cutting edge of what is possible." "When it comes to science fiction, we love to be led into a world of imagination and fantasy." "With "Stargate", we travel to other worlds and pass through time." "We meet creatures from other galaxies and find out about gods and mortals." "We cover huge distances in time and space, and find technologies that seem beyond our wildest dreams." "But maybe the biggest surprise of all, though, is that everything we've seen is actually possible." "Modern science may actually be the most wild, fantastic voyage of imagination that we're capable of." "And of course, in "Stargate", nothing is ever as it seems." "In the actual Cheyenne Mountain Complex, there is a door that has multiple locks on either side and a blacked-out glass window and above it, it says," ""Stargate Command"." "It's a broom closet." "It really is a broom closet!" "But... or maybe it isn't." "Maybe that is how you get there."