Game of Thrones is a show that requires a serious suspension of disbelief. It exists in a universe where the dead can rise from their graves, humans can see through the eyes of animals, anyone can travel between Dragonstone and Eastwatch at or near the speed of light, and Jon Snow can hold an unbroken frown for seven straight seasons.
Still, as we anticipate the premiere of Game of Thrones's eighth and final season on April 14—and as we remember cowering each time Drogon hovered in midair to pour a throatful of flame over one of Daenerys Targaryen’s enemies in last season's big-budget battles—we started to wonder: Could a beast that big really maneuver through the air like that? Fortunately, two scientists who have dedicated their lives to studying flying creatures agreed to clear that up for us.
Kevin McGowan, a Cornell ornithologist who specializes in crows, says there’s one major problem with dragon flight: physics. “They’re just so damn big,” he says. “Way too big to ever get off the ground.”
For comparison, there's the albatross, which weighs around 25 pounds and needs a 10-foot wingspan in order to heave itself into the air. And birds don’t scale up easily. McGowan says that as a bird gets heavier, its wingspan has to grow exponentially to keep up: “If you need a 10 foot wingspan for a 25-pound bird, what would you need for a 2000-pound dragon?” (Last season, one eagle-eyed engineer estimated that Drogon weighed around three tons and flew with a wingspan under 60 feet—and the dragons are even bigger now.)
In the real world, bird species generally stay small to avoid having to grow their wings exponentially. Those that do grow large wings, like the albatross, can travel long distances—but pay the price in maneuverability. Birds with smaller wings can maneuver in tighter spaces, but have to expend much more energy to stay aloft. “Birds make a lot of compromises to fly,” McGowan says, “and dragons just aren’t doing that.”
Still, there is some hope for letting our dragon-sized fantasies take flight. Michael Habib, a paleontologist and assistant professor of clinical integrative anatomical sciences at the University of Southern California's Keck School of Medicine, studies the flight mechanics of extinct animals, including giant pterosaurs once thought to be too big to get off the ground. He also works with film studios like Disney, Marvel, and Lucasfilm to design believable flying monsters like griffins, hippogriffs, and pegasi. There are three tricks, he says, for plausibly scaling up fantasy flying creatures.
First, you want to give them the right wing type. Like modern day bats, pterosaurs—which lived from 228 to 66 million years ago—had membrane wings, made of skin stretched over a series of elongated fingers. These are good for slow, maneuverable flight, and they don’t have to be as large compared to the body as a bird’s feather wings. Habib tells Mental Floss that a dragon with a good pair of wings would be able to sustain flight easily once it was in the air—but it could only get there “if it came with a catapult for takeoff.”
Second, a dragon needs to have the right skeletal structure. Their bones should be strong enough to withstand the massive mechanical forces involved in flight without getting too heavy. Hollow bones are best; they're actually stronger than a very dense bone with a similar mass. Habib explains that’s because the bone’s ability to withstand the strain of flight depends on its diameter—the wider it is, the more force it can take. A hollow, air-filled bone can be much wider than a dense bone full of marrow, and it will still weigh less than the dense bone.
Third, and most importantly, a dragon needs to have as much power available for takeoff as possible. Habib says that almost every animal that takes flight, from birds to flying squirrels to winged snakes, gets into the air by jumping, not flapping its wings.
“What birds get stuck on is they only have two hind limbs available for jumping power,” Habib says. “Bats do better—and pterosaurs did, too—because they walk on their wings and they can jump off of all four limbs.”
That makes a big difference, especially because most of a bird’s strength is in its wings. While birds take off with less than half their bodies’ muscle power, bats and pterosaurs launch themselves with everything they’ve got. That’s what allowed the largest pterosaurs to grow into 550-pound behemoths, while the heaviest-ever flying bird—the extinct Argentavis magnificens—maxed out around 150 pounds.
The dragons in Game of Thrones do have membrane wings, and they could conceivably have hollow bones. Back in season three, WIRED reported that the show’s animators based the dragons on a cross between an eagle and a bat. (Their strenuous, flappy hovering certainly takes after fruit bats.) Although the dragons walk around on their wings like bats, they don’t seem to jump off of them during takeoff. Throughout the series, we see them dive from cliffs and glide into flight, leap off their hind legs after a running start, and sometimes just flap their wings and leave the ground.
Habib says even if a dragon followed all of his specifications, it could only grow up to about 1000 pounds without grounding itself—not several tons, like Daenerys’s children.
“They’re probably beyond the flight limit for any anatomy,” Habib concedes, “unless they’re secretly made out of carbon fiber and titanium.”
“Maybe they’re full of hot air,” suggests McGowan, “or maybe it’s just magic.”
And what would happen if a dragon got a hole in one of its membrane wings, like Viserion displays after rising from the dead in the finale of season seven? Could it still fly? "The short answer is, probably a bit, but not as well as normal," Habib says.
Bats can fly with similarly damaged wings thanks to the way wings move through air. We tend to think of them as paddles pushing the air, but wings actually pull air. Like any other fluid, air has a certain amount of intrinsic stickiness to it, so air sticks to other air. "As the wing is pulling on the air, it's flowing over and around the wing, and it will skip over the air within the wing's small gaps and imperfections just as water will jump over the holes in a storm grate," Habib says. "Obviously, the more holes you put in the wing, the more inefficient it becomes, but it will still work up to a point. If there are too many holes, it will fail."
To McGowan, though, how the dragons fly doesn't really matter: “I think all day. When I go home, I don’t want to think anymore. I can just say it’s magic. I don’t care.”