I’m not big on pointing out the science that Hollywood gets wrong — the last thing I want to do is yuck anyone’s yum. But as a physicist, I couldn’t help but notice all the fun real-life science hidden in the dragons and ice walls of Game of Thrones. There are more than a few fan sites devoted to the science problems of walls and dragon speed, including Neil DeGrasse Tyson‘s regular tweets about Game of Thrones fun facts. But below are a collection of 10 particularly interesting things about the science of Westeros that you may not have picked up on before, explaining some of the fact behind the fantasy. (I feel like I should get a link in a maesters chain for this…)
1) After Ned was beheaded, he was probably aware of the crowd for another 10 seconds.
Stop now and count to ten. It’s not a short amount of time, is it? Since the invention of the guillotine, there have been questions as to whether or not a head is conscious after it is severed from the body. The thought was that consciousness ended only after all the blood flow to the brain had stopped, and that took a bit. Ischemia, the technical term for cessation of blood flow to the brain, would stop neurons from being able to fire. During the French Revolution scientists would ask the condemned to try and blink or talk after beheading with minimal success. But then, a group from the Netherlands decided to figure it out by putting electrodes in rats’ heads and beheading them using a rat-sized guillotine. Based on the length of rat brain activity, the group extrapolated to humans and theorized that beheaded humans would be conscious for roughly ten seconds after beheading.
To put beheading in a cultural context, the last judicial execution by guillotine was after the first Star Wars movie was released, the year that Atari hit the shelves, and the year you could buy your first Apple II computer. Jimmy Carter was president and several months later, one of the best-selling albums of all time, Meatloaf’s Bat Out of Hell, was released.
2) An ice wall probably wouldn’t work, but the army tried it once.
Ice walls are really a great idea in terms of defense. They can’t be burned down, they would absorb projectiles, and they would be really hard to breach. The material is abundant and cheap, and glaciers would lead you to assume they were possible. Unfortunately, a wall like the one described in Game of Thrones would not stand up over time, even if the North was really, really cold. Glacier scientist Dr. Martin Truffer from the University of Alaska did simulations of the Ice Wall based on equations that show how glaciers creep over time. He found that after 1,000 years, the time the Ice Wall is said to have stood, it would look more like an ice ramp.
Bran the Builder wasn’t the only person to try building with ice, though. During World War II, Allied forces needed more aircraft carriers to get enough planes to the Northern Atlantic. They needed something that was cheap to build, couldn’t be burned, and couldn’t be destroyed with U-Boats. And it didn’t need to be built to last. Using Pykrete, a mixture of ice and sawdust developed by Geoffrey Pyke, army engineers set about figuring out if it was possible to build an aircraft carrier out of sawdust and ice. Mixing in sawdust made the ice considerably stronger. The project moved forward but was ultimately scrapped because airplane technology advanced enough for the “berg ship” to no longer be needed.
3) An exploding moon could be responsible for the planet’s unpredictable seasons.
Our Earth has regular seasons for a number of reasons, but one biggie is that Earth’s axis of rotation is not just tilted, it’s tilt is also pretty stable over time. The axis is tilted at 23.5o though it varies a little over long time scales. The moon works to stabilize this tilt. A group of scientists from Paris did simulations on what would happen to the tilt of the Earth’s axis if it were different from 23.5o and also what would happen if there were no moon. What they found was that our Earth is at a bit of a cosmological sweet spot. If Earth had a tilt of between 60o and 80o the moon wouldn’t still be able to provide stability and Earth would be wobbling all over the place. If there were no moon at all, Earth would no longer be stable at any tilt and our seasons would be completely unpredictable. The French group’s models could explain the legends of Game of Thrones. According to a Lysene legend (from the book not the show) there were once two moons:
“He told me the moon was an egg, Khaleesi,” the Lysene girl said. “Once there were two moons in the sky, but one wandered too close to the sun and cracked from the heat. A thousand thousand dragons poured forth, and drank the fire of the sun. That is why dragons breathe flame. One day the other moon will kiss the sun too, and then it will crack and the dragons will return.”
If there used to be two moons helping the planet stay stable and one exploded, the axis of rotation would be thrown into chaos and the seasons would be completely unpredictable, leading to events like The Long Night.
4) The Night King and wights may not be real, but nature is full of real-life zombies and zombie parasites.
There are various types of zombies in movies and TV, from the ones focused on a single goal (brain consumption) to those that are being controlled by a puppet master like the Night King. Our natural world is also freaky enough to have very similar types of zombies, including some that are even scarier. Real diseases and parasites can cause organisms to act like zombies, bending to the diseases’ will. Rabies often looks very similar to zombiism, to the point that there have been complaints of “Zombie Raccoons” in Ohio. The infected animal foams at the mouth, walks stiffly on their hind legs, and will fall into a comatose state. So yes, get your pets vaccinated against rabies even if they are indoor only pets — you don’t want them to become zombies.
Toxoplasmosis, which many of you readers are probably already infected with, causes its host to really like cats. Mice infected with the protist will lose their fear of cats and humans infected with it will have a hard time saying no at adoption events. The cat will eat the infected mouse and toxoplasma gondii will reproduce in the feline’s digestive tract.
Crustaceans aren’t immune to zombies, either. Sacculina carcini is a barnacle that hijacks the green crab’s reproductive system and uses it as its own. The crabs care for the barnacle’s eggs and continue the cycle, living for up to two years in their zombie reproductive state. Nature is weird.
5) Valyrian Steel may have had carbon nanotubes.
Valyrian steel is based on real-life Damascus steel. It had the sharpest edge of any weapon and was said to be able to slice through a human hair the hard way. Unlike other types of steel weapons, it had a very high carbon content making it potentially very brittle. Westerners were unable to take this brittle steel and make it into weapons. However, smiths from Damascus used the same steel and made it into the finest swords in the world. The method for making these weapons was lost, but several modern scientists have attempted to find its secret. One group led Alexander Levin from Dresden, Germany, took the edge of a Damascus steel blade and ran it through a very sensitive X Ray machine. They found that the sharp edge was made by carbon nanotubes wrapped around steel. Carbon nanotubes are about five times stronger than steel and are 50,000 times smaller than a human hair. The slow process of smelting and working the steel allowed the carbon nanotube to form.
The swords were also said to be quenched in the urine of red headed boys … and actually, the team theorized that the acidic urine would eat away some of the steel and leave the nanotubes exposed. No wonder they could cut through a human hair, the skull underneath, and a White Walker!
6) Wildfire could be real, just probably not green.
Throughout history there have been examples of fire with the properties of Wildfire. Greek fire is probably the best and most referenced example. It has all the properties of Wildfire except one; it doesn’t burn green. It did, however, burn on water and could only be put out with vinegar or sand. Invented by a now unknown Greek and used by the Byzantine Empire, Greek Fire was a flammable compound and a delivery system mostly used at sea. The making of Greek Fire was a state secret so very few records remain. But, similar to Damascus steel, modern scientists wanted to figure out how it worked. The flammable compound was probably made of pine tar, Sulphur, and potentially either saltpeter or quicklime. It was fairly stable until deployed through a siphon which was thought to be a bellows type system, which would spray the compound and light it on the way out. Unfortunately, it didn’t have any elements that would burn green. If copper sulphate and boric acid are burned, though, the flame is bright green. It’s possible that Wildfire is a combination of Greek fire and either one of these two compounds.
Napalm plus copper or boric acid might also be a contender for real life Wildfire — it is a horrible weapon, but has many of the same properties. It is difficult to put out, burns on water, burns hot enough to melt steel and stone, and will stick to its target. But unlike Wildfire it’s very hard to ignite. This is one of the reasons it was used as a weapon so effectively. It could be transported without blowing up the transport ship. Don’t Google how to make it, though, unless you want to get to second base with TSA.
7) Sleeping with your sister is a bad idea but marrying your cousin is probably fine. Marrying your third or fourth cousin is ideal.
Incest seems to be how the 1% rolls in Westeros. To some degree incest isn’t as terrible as society would have you believe. Iceland has a very small population, 270,000 give or take, which means accidental incest can happen. They even have an app so that you can see how you are related to your potential date, just in case. If you are your date’s third or fourth cousin, however, don’t call things off. Iceland keeps a database of everyone’s genetic material. Scientists can look at this database to see how related you may be to your spouse.
When a group of scientists wanted to see how bad incest really was, they looked at the number of kids and grandkids that related couples had vs. unrelated couples. What they found was that couples who were first and second cousins had about as many children and grandchildren as couples that were completely unrelated. Third and fourth cousin couples, however, had the most children and grandchildren of the couples studied. If you want to reproduce, it seems that the ideal level of related is third or fourth cousin. But if you do decide your cousin is hot, there is only a statistically small increase in birth defects in the children of cousins vs the general population. Wanting Jon and Sansa to get together, for example, isn’t actually weird at all — but it would be better if they were slightly less related.
8) With strong enough bones, dragons really could fly.
The moment when Drogon swoops in and torches the Lannister caravan was so beautiful it made me tear up a bit. I had been waiting for that moment for six and a half seasons. For Drogon to fly like that he had to have super strong magic bones. For something to move in one direction there must be a force in the other direction. When you swim you push the water back with the same amount of force the you go forward. For something to fly it must push air down with at least as much force as it weighs, i.e. when a plane flies the shape of the wing pushes air down with enough force to lift the plane. In the case of winged dinosaurs, they would use their huge muscles to push the air down with the amazing amount of force that would been needed to lift their huge frame; Pterosaurs did this very effectively and could get quite large. The largest flighted dinosaur, Quetzalcoatlus northropi, was around 550 lbs.
The limiting factor in pterosaur flight wasn’t their muscles, it was their bones. Any bigger than Quetzalcoatlus northropi and the force needed to push down is greater than the force needed to break a bone. Something the size of a dragon would require generating so much force to lift that the bones in his wings would break. If, however, the magic of dragons was housed in their bones, they would be able to fly. And torch Lannisters.
9) Jon Snow should probably wear a hat, but not wearing a hat isn’t going to kill him.
Though Kit Harington has some amazing hair, it’s not going to keep him as warm as would a hat. Hats work by keeping the warm air produced by your body radiating heat close to your head. Though Jon’s hair may be as thick as a hat, when it blows in the wind the hot air escapes and cold air comes in. His body then loses more heat while trying to heat up the cold air. A thick wool hat would keep warm air close to his head, but contrary to legend, the body does not lose most of its heat through the head. Heat is lost from the body when warm blood loses heat to outside air. Since there is a lot of blood flow to the head, it’s easy to think that it would lose a lot of heat.
The head also has very little fat to insulate the body. Scientists at the University of Manitoba wanted to test this myth experimentally, so they dunked people in cold water up to their neck or over their heads and measured the difference in heat loss. The head loses heat at about the same rate as the rest of the body. So yes, Jon should wear a hat, but it’s no worse than not wearing gloves. Frostbite on his ears might be another story, though …
10) The most merciful death was probably Viserys. I’m as bummed as you are.
There are some deaths in Game of Thrones that are nothing short of delicious. Joffrey was certainly one, but the death of Viserys was so satisfying, particularly because of how he died. While it’s true that a fire wouldn’t be hot enough to melt gold, I’m happy to suspend disbelief on that in favor of enjoyment. But if you look into the science of how someone would die if molten gold was poured on their head, it becomes a bit less gory. Molten gold has a temperature of 1064o C or about 1947o F. When something that hot is poured on a head the heat very quickly will be conducted into the brain. The brain is mostly water and when water gets hot, it boils. Like in beheading, as soon as neurons stop being able to fire, a person can no longer think or feel pain.
The pain Viserys felt will depend on how long it takes to cook his neurons. The brain is about 1.4 kg and roughly 73% water. With the temperature of molten gold and how fast heat can get to Viserys’ brain, it would take about 3.5s for his brain to fully boil. He probably lost consciousness long before that. Count to 3. It feels so short in comparison to the ten seconds it would take to die by beheading. This makes me very sad. He deserved much worse. Rats and a bucket perhaps?
The final season of Game of Thrones airs Sunday, April 14th on HBO.