The Real-Life Science Behind The Summer's Most Outrageous Sci-Fi MoviesIn Edge of Tomorrow exoskeletons play a critical role in humanity s desperate last stand against alien invaders. It would be easy to assume the futuristic systems are digital illusions mapped to the actors  movements but they re actually elaborate props. The modeler Pierre Bohanna made each suit from 350 to 400 discrete components that together form a fully articulating device. The materials include standard nylon high-grade aluminum and a lightweight polymer created specifically for the film.  It s not a costume Bohanna says  it s a machine.  Unfortunately for the actors the humans power the suits not vice versa. They had to sprint through battle scenes lugging 72 to 132 extra pounds.  These things were incredibly hard work and all of the actors and stunt guys had to do boot camp in them says Bohanna. That sweat on Tom Cruise s brow? It s real too.   The Answer: There s nothing mysterious about Hollywood s love affair with humanoid aliens. It s easier to throw prosthetics and face paint on actors than it is to fabricate (or animate) menageries of wildly inhuman characters. But if we apply lessons from our own evolution to other worlds then filmmakers might not be so far off.  According to Stuart Sumida a biologist at California State University at San Bernardino who served as a consultant on Guardians of the Galaxy an alien advanced enough to master space travel would need to have a large brain.  If you have a big brain you need a way to protect it Sumida says. That means a skull which rules out whole taxonomies of worms slugs and other potential invertebrates. And because exoskeletons would become untenable as they scale up in size collapsing under their weight in all but the lowest gravities insects can be reasonably ruled out. Throw in the ability to manipulate tools and our otherworldly companions start to look pretty familiar.  But even with prominent brains bones and dexterous appendages there s no reason to assume that distant species would look like slight variations of us.  The fact that we have four appendages is an accident of evolution says Seth Shostak senior astronomer at the SETI Institute in Mountain View California.  Most of the critters on our planet have six. Natural selection could produce aliens with a more efficient physiological layout: Instead of walking on two legs for example which enables  humans to hold babies and tools while on the move an  extraterrestrial might have more speed and stability on four or more lower limbs. They could have more arms for  manipulating tools ground-hugging postures to better hide from predators or any number of features that don t mesh with the Wookiees Klingons and other near-humans that make up science fiction s interspecies melting pot.Inspired by  Guardians of the GalaxyThe Plot: After stealing a mysterious orb from the wrong guy �an alien hell-bent on galactic domination �a group of criminals become unlikely heroes. Although the swashbuckling sci-fi flick is part of Marvel s combined cinematic universe (along with The Avengers) most of its larger-than-life characters aren t superhumans but humanoid aliens.Sci-Fi Debut:  H.G. Wells  1901 novel The First Men in the Moon features the dwarfish insectoid Selenites who wear clothes use tools and don t take kindly to visits from Earthlings.New Orleans in mid-July is no place for a chimp. The sweltering mosquito-assaulted set of Dawn of the Planet of the Apes is a minor marvel of engineering a three-story habitat with  interlacing tree trunks recessed rooms and passages and a flowing aqueduct that s turned the ground level into a swamp of pooling water and sucking mud. The filmmakers call it Ape Village and it really does look like something hyperintelligent domineering apes might construct. Until that  is you notice the dozens of  motion-capture cameras dotting the structure and the guys in gray full-body suits broiling in the merciless sun and steamy humidity. They re the sweatiest most miserable make-believe chimps imaginable.And then they start to move. Two of the gray suits scramble up the sides of the habitat grabbing camouflaged handholds without the benefit of safety harnesses or mats. They leap between set elements like trained acrobats which in fact they are. While Rise of the Planet of the Apes (released in 2011) relied on stunt people the sequel to the sci-fi reboot has cast Cirque du Soleil performers.  Instead of a VFX [visual effects] guy trying to make up what it would be like for a chimpanzee to fly from limb to limb now we have guys that can actually jump the 20 feet says producer Dylan Clark.  From a VFX standpoint Dawn of the Planet of the Apes isn t a single leap of faith but a series of them. The first movie redefined what was possible with performance capture turning Caesar a chimp played by Andy Serkis into a believable full-computer-generated (CG) character. Dawn features a much larger cast of apes and their expanded screen time makes for a much bigger challenge. Standard procedure for performance capture is to confine actors to indoor green-screen environments and rely solely on head-mounted cameras to film their actions. For Dawn VFX supervisor Joe Letteri decided to gather data on an outdoor set by surrounding the actors with constellations of small motion-capture cameras.The cameras track LED-lit balls Velcroed to the actors  suits and reflective markers applied to their faces.  Then we use a learning algorithm to give us the best guess of what all the points of the face are doing in three dimensions Letteri says. The result is performance capture that s extremely detailed and flexible as multiple cameras pick up nuances of expression and chemistry between actors that might otherwise be lost. With more data at their disposal animators can imbue the entire supporting cast of 3-D �modeled primates with the same uncanny flicker of intelligence that made Caesar an instant CG star.It s this mixture of practical and digital human and inhuman that will make or break Dawn. Because unlike the monsters mutants and other VFX-enhanced flights of fancy populating sci-fi flicks apes (even smart ones) aren t imaginary.  We want the chimpanzees to act and look and be photorealistic Clark says.  We want this movie to feel real. If we pull this off it ll be supercool. The Answer: The filmmakers of Jupiter Ascending augmented human characters with animal genes to make them more physically imposing. In reality human-animal hybrids have never been people with animal traits but rather animals tweaked to host or benefit from human biology. The first documented example occurred in 2004 when the Mayo Clinic injected human stem cells into fetal pigs creating swine with human blood in order to study how viruses jump between species. Last year neuroscientists at Stanford University boosted the intelligence of mice with human brain cells. In both cases researchers sidestepped any actual genetic engineering by simply introducing foreign tissue and letting it take root.In theory similar experiments on humans could yield incredible results such as modifying photoreceptors to enable catlike night vision or borrowing a newt s ability to regrow amputated limbs. But even if blithely injecting human fetuses with feline or amphibian cells weren t an ethical black hole (and it absolutely is) the brute-force approach could easily backfire: The body s immune system typically attacks alien tissue. The Stanford team avoided rejection by permanently suppressing their subjects  immune systems  
a solution that would leave  humans vulnerable to catastrophic disease and infection.According to Randy Lewis a biologist at Utah State University the problem with chimeric enhancements is their complexity. It s one thing to flip a single protein as he did to create transgenic goats that produce spider-silk protein in their milk. But adding complex traits like strength or regeneration?  To do that requires a tremendous amount of genetic engineering says Lewis. Until scientists achieve a profound understanding of human and animal genomes superhuman hybrids will remain little more than a cinematic confection.Inspired by  Jupiter AscendingThe Plot: The universe is filled with human-animal hybrids and ruled by an intergalactic monarchy (news to Earthlings). When an unassuming janitor is targeted for assassination a part-human part-canine mercenary comes to her rescue.Sci-Fi Debut:  The Beast Folk lurching through H.G. Wells s 1896 novel The Island of Dr. Moreau are created through grisly surgical experiments.The most technically challenging scene in Jupiter Ascending shows the movie s hero (Channing Tatum) zipping through the city in antigravity boots fleeing a spaceship in pursuit of his cargo (Mila Kunis).  Most people will probably think it s digital but it s not says VFX supervisor Dan Glass. Rather the sequence features stunt doubles suspended from a helicopter as it banks through Chicago s urban canyons.  Glass s team had only 15 minutes a day to film the scene ­ �a tiny window of predawn light ­ �so they created a camera capable of squeezing more photography into each shoot. Mounted to the nose of a helicopter the six-camera rig (called the Panocam) could capture nearly 180 degrees of footage.  
By stitching together multiple overlapping angles the filmmakers could effectively pivot and swing through the action in postproduction regardless of the helicopter s actual flight path. Not surprisingly the innovation quickly attracted the attention of other directors.  That rig is now used on most of the movies that followed us says Glass.The Answer: The giant alien robots in Michael Bay s Transformers franchise aren t built in factories. They re grown in egglike pods and referred to as hatchlings and they exhibit the kind of physical and behavioral diversity that implies something closer to biological reproduction than mass assembly. Just as no two humans are identical (with the exception of twins) each Autobot and Decepticon is unique in character and form whether it s a humorless tractor-trailer or a hot-tempered Tyrannosaur.  The Transformers in other words seem to be products of evolutionary robotics a burgeoning field of research that applies biological principles to the creation and behavior of robots. Rather than simply engineering a bot to perform a given task such as moving toward a light researchers can plug that goal into a computer program and let genetic algorithms automatically breed a variety of designs. And since those algorithms mimic nature modeling the effects of mutation selection and other biological processes the designs they produce are often surprising.  The computer will evolve machines for us that have shapes we would never have thought of says Josh Bongard an evolutionary roboticist at the University of Vermont. Even with very few parts and motors at their disposal bots born from algorithms have eked out efficient locomotion from such varied forms as an undulating fish and a shuffling pyramid.In other words robots that evolve whether by gestating in eggs or via genetic algorithms could benefit from the same diversity and convenient mutations that make some living species so resilient. But just as unchecked Transformer reproduction could be bad news for any humans caught in the inevitable crossfire machines could be dangerous too Bongard cautions if they were to evolve without strict guidance.  Self-reproducing robots would by definition be a runaway process he says.  They could surprise us in unpleasant ways. Inspired by  Transformers: Age of ExtinctionThe Plot: The fourth installment in the Transformers  series continues the story of a race of robots at war with itself. Joining the battle this go-round is the species  most exotic  specimens yet the Dinobots.Sci-Fi Debut:  Karel Capek s 1920   play R.U.R. ends with a pair of factory-built lovers seemingly destined to become the new world-populating  Adam and Eve.The Answer: Science fiction has long relied on mutation as an evolutionary shortcut. Sometimes it s the work of external forces as with the atomic testing that gave rise to Godzilla in the original 1954 film and the glowing  ooze that turned garden-variety turtles into man-size martial artists. At other points it s a naturally occurring hiccup like the  X-Gene that allowed superhumans to manipulate brain waves or magnetic fields. The common thread is speed: Within a single generation the protagonists are transformed.It s an interpretation that s correct in spirit: Genes can mutate spontaneously or be manipulated in the lab to create new traits. Take for example the ability of most adult humans to process lactose in dairy products. Researchers believe this mutation a kind of gastrointestinal superpower began in Europe some 7500 years ago. The sudden change led to a significant long-term benefit for our species enabling us to add a range of nutritional options. While humanity owes a debt to that mystery mutant cheese-eating is a minor ability compared to the laser beams and claws erupting from X-Men.Bruce Demple a biochemist at Stony Brook University cites more dramatic examples of single mutations � the kind of things that screenwriters might think about he says.  But mostly you see these things in experimental settings. With targeted chemical mutagens geneticists have pulled off feats both impressive such as increasing the circumference of macaque monkeys  thigh muscles by 15 percent and flat-out disturbing like making legs sprout from the heads of fruit flies. Researchers have also used radiation to increase random mutations.  But the difference between these lab-grown mutants and their Hollywood counterparts comes down to luck. Movie characters didn t just win the mutation lottery once gaining a single incredible ability without chemicals or radiation mortally fraying their DNA. They won again and again packing on good traits dodging bad ones and transforming into creatures that would normally require multiple generations and countless failed attempts. In reality the road to monstrous success would be paved with the corpses of almost-Godzillas and near �Ninja Turtles.Inspired by  Godzilla TMNT X-Men: Days of Future PastThe Plots: Godzilla clashes with even more malevolent titans the Teenage Mutant Ninja Turtles fight crime in (and under) New York City and the X-Men send Wolverine back in time to prevent a robot uprising. In all three films mutation unleashes the organism s inner badass.Sci-Fi Debut:  Radiation exposure transforms The Metal Man of Jack Williamson s eponymous 1928 short story into the  progenitor of today s fictional mutants.Let s assume the worst: that aliens exist and they re invading our humble home world. What sort of high-tech weapons would a desperate human race rush out of the lab and into battle? We asked Suveen Mathaudhu
a program manager and materials scientist at the U.S. Army Research Office what we could plausibly throw at such a doomsday scenario.Combat exoskeletons like the ones in Edge of Tomorrow could enable infantry to carry increased firepower Mathau ­dhu says. Guns that would normally generate too much recoil for the human body could instead be mounted on the suit distributing that force throughout the frame. Today s exosuits are too power-hungry to be effectively fielded but the use of titanium magnesium and other ultrastrong ultralight alloys could reduce their energy consumption.  You re going to have lower fuel usage because you re not carrying around a steel exoskeleton Mathaudhu says.If the common cold can repel Martian occupiers in The War of the Worlds why not hurl even more virulent weapon ­ized bugs at the enemy? Although bioweapon stockpiles are in short supply (with very good reason) Mathaudhu is confident that geneticists could synthesize whatever new plagues seem useful.  If we assume that life evolved similarly in other parts of the universe wherever these creatures came from our tools may work similarly on them he says. The technology that has revolutionized genetic analysis allowing for whole-genome sequencing of human DNA could also enable a precision pathogen of last resort.  When push comes to shove we d shove robots onto the front lines.  If we were forced into some sort of Apollo moment by a massive war the majority of the efforts would go toward unmanned ground vehicles and robotics Mathaudhu says. A robot army might be less versatile than a living one but the bots would excel as cannon fodder during the early stages of conflict providing intel on alien weapons and tactics before being blown to bits.  The hesitation to put a soldier in the field against an unknown threat would be countered by robotic technology Mathaudhu says. Who needs nerves of steel when your soldiers are made of it?    This article originally appeared in the July 2014 issue of  Popular Science.