With Game of Thrones now back with season six, audiences everywhere are once again gluing themselves to the TV screen every Sunday night to find out what new horrors will befall their favorite remaining characters. One of the reasons why the show has remained so insanely popular for half a decade is because of the ways it seamlessly blends subtle magic with real world elements to constantly keep viewers guessing as to just what’s possible in the world of Westeros (Jon Snow just needs a little milk of the poppy and he’ll be good to go, right?). So whether you’re searching for real life evidence to help support some the fantasy elements in the series, or you’re just looking to brew up a little Wildfire in your parents’ basement, be to check out these 11 ways that Game of Thrones can be explained with science. SPOILERS AHEAD.

11. Milk of the Poppy Is Pretty Much Morphine

Milk of the poppy is basically Game of Thrones‘ standard painkiller and is usually administered to patients who are suffering from severe wounds or who are undergoing surgery. It seems to work in much the same way that morphine does, which shouldn’t come as a surprise since, as anyone in the medical field will tell you, morphine is derived from the poppy plant.

10. The Crazy Seasonal Patterns Could Be Caused by a Wobbly Planetary Rotation

Here on Earth, our changing seasons are caused by the tilt of the Earth’s rotational axis away or toward the sun as it travels through its year-long path around the sun. Half of the year the Earth’s location in its orbit will tilt the northern hemisphere towards the sun, bringing on summer, and the other half of the year the northern hemisphere tilts away from the sun, meaning winter is coming. Of course, the same thing happens in the southern hemisphere as well, only the seasons would be reversed. The important thing to note is that, while the Earth’s axis of rotation has remained quite stable—a factor that is largely attributed to the presence of our sizeable moon—if it wasn’t, and the planet had more of a wobble to it, we would likely experience much more inconsistent and unpredictable seasonal lengths. Perhaps not unlike those seen in Game of Thrones.

In the series, according to legend, Westeros once had two moons but one of them “wandered too close to the sun and it cracked from the heat” pouring out a thousand dragons. So it’s possible that some sort of cataclysmic astronomical event in the past obliterated their second moon and messed up their planet’s rotational axis.

9. Valyrian Steel Is Pretty Much Damascus Steel

In Game of Thrones, Valyrian steel is a mysterious metal whose secret alchemical formula has supposedly been lost in time like so many other ‘magical’ elements in the series. From what we’ve seen, the steel is unmatched in terms of its incredible strength and ability to retain a remarkably sharp edge—two notable properties that were also once said about the real world alloy known as Damascus steel. Just like Valyrian steel, the original method used to forge Damascus steel is not known, and although modern attempts have been made to replicate the metal, those efforts haven’t been all that successful due to differences in raw materials and manufacturing techniques. A closer examination of Damascus steel reveals a complex structure of nanotubes and nanowires that give the metal its strength and flexibility. Some believe that it’s the presence of woody biomass in the metal ingots that, once burnt away in the smelting process, gives the alloy these properties. Interestingly enough, swords forged by Damascus steel are described as having distinctive patterns of banding and mottling reminiscent of flowing water—a characteristic that also seemed to be exhibited by Valyrian steel swords such Ice and Longclaw, that have been seen in the series.

8. Crushing a Human Skull With Bare Hands

One of the most brutal scenes ever witnessed on television was when the Mountain crushed Oberyn’s skull in season four of Game of Thrones. But could such a feat of strength ever be accomplished in the real world? Well, according to a study published in the Journal of Neurosurgery, the answer is…probably not. After soaking cadaver skulls in fluid to mimic the warm, squishy living tissue that would normally surround them in a living person, scientists exerted huge amounts of pressure on them to see how well they held up. The results showed that the average skull would experience “catastrophic failure” at around 520 pounds of static force. Since Thor Björnsson, the actor who plays the Mountain, weighs in at about 400 pounds, he likely wouldn’t have been able to crush Oberyn’s skull even if he stood on it, let alone through the force generated solely by his upper body. However, that doesn’t necessarily mean that it’s impossible to crush a human skull using bare hands. Thanks to the properties of acceleration, a boxer’s punch can generate up to 5,000 Newtons of force. So, although it might not be possible for the Mountain to squeeze Oberyn’s brains out of his skull like the jelly in a doughnut, he could certainly punch him hard enough to make his head explode—which is arguably just as cool.

7. The Crazy Seasonal Patterns Could Be Caused by an Extremely Elongated Orbit

Another explanation for Game of Thrones’ winters that can last a lifetime relates to the orbit of the planet around its sun. As we’ve already mentioned, the different seasons on Earth are caused by the tilt of the planet’s rotational axis, not by its orbital position around the Sun as many people might have you believe. Thought it’s true the Earth does follow an elliptical orbit, it’s practically a circle, meaning our distance from the Sun at the aphelion point has a negligible effect on our climate. However, not all of the planets in our solar system exhibit such a circular orbit. For instance, Mercury’s elliptical orbit gives it much more variability in its distance from the Sun which could have significant impacts.

In Game of Thrones, it’s possible that their world has a very elongated orbit which results in winters being  extremely cold and prolonged. However, this theory still wouldn’t account for the unpredictability of the seasons. The inhabitants of Westeros would still experience annual cycles of consistent seasonal lengths, so there would have to be another piece of the puzzle to explain that phenomena.

6. Dragons Can Be Explained Through the Properties of Existing Animals

Dragons are one of the most beloved and reoccurring elements in all of fantasy, so of course there are hordes of Game of Thrones fans who have probably dreamt about sailing through the clouds on the back of a massive fire-breathing beast. But if you look at some of the crazy characteristics that are exhibited by creatures in the real world, the existence of dragons actually seems much less far-fetched.

Any climate scientist will tell you that cows and pigs are basically just organic bags of flammable methane that contribute to our worsening global warming situation. And bombardier beetles possess a defence mechanism that allows them to expel a burning chemical spray from their bodies. We also know that various aquatic animals are capable of producing electrical sparks, so if all these traits were someone incorporated into a winged lizard species like draco volans (commonly referred to as the flying dragon), then you’d have genuine dragon on your hands—albeit a much smaller version.

5. Wildfire Is Pretty Much Greek Fire

Much like Valyrian steel, Wildfire is another Game of Thrones concoction that was taken straight from real world history books. The volatile material, which explodes with tremendous force and burns with a fire that water cannot extinguish, played a key role in season two during the Battle of the Blackwater when Tyrion unleashed it on Stannis Baratheon’s invading fleet. But other than than having a distinctive green hue, there seems to be very little difference between the fictional Wildfire and the legitimate substance known as Greek Fire.

During the seventh century, Greek Fire was used to great effect in a number of naval battles and, although no one left a chemistry textbook lying around that explained exactly how to make it, it’s believed that it was formulated from naphtha, quicklime and sulphur. Just like Wildfire, Greek Fire can burn on water and won’t be extinguished by it, making it the perfect weapon for naval warfare. And theoretically, if they wanted to turn it green, they probably could have just added a bit of copper oxide to the mix.

4. The Crazy Seasonal Patterns Could Be Caused by an Intense and Complex Milankovitch Cycle

A Milankovitch cycle describes the collective effects that changes in a planet’s movements have on its climate. For example, variations in Earth’s axial tilt, orbital eccentricity and precession, can create climactic patterns that can take tens of thousands of years to play out. It takes our planet roughly 26,000 years to complete one full precession cycle, and when you combine this factor with the phenomena that the Earth also moves at variable speeds over the course of its orbit, it makes for an astronomical season, or Milankovitch cycle, that lasts more than 20,000 years.

This extremely long-term seasonality has the effect of gradually changing the planet’s climate and is thought to have been the cause of Earth’s past ice ages. Other planetary bodies in our solar have noticeable Milankovitch cycles as well, with Mars’s polar caps varying in size on account of its orbital instability, and Saturn’s moon Titan experiencing a 60,000 year cycle that sees the locations of its methane lakes change over time.

Examining the situation in Game of Thrones, it could be possible that elongated and inconsistent seasonal shifts in Westeros are caused by a very short and very complicated Milankovitch cycle. Were this indeed the case, their seasons would be marked by variations in both length and severity, which is exactly what seems to be the case with summers that can last a decade and winters that can last a lifetime. And although such long-term trends could eventually be predicted with some astrophysical analysis, that type of scientific study might just be beyond the reach of the medieval maesters in Game of Thrones.

3. Hodor’s Mental Disposition Could Be Explained by a Condition Called Expressive Aphasia

Though his vocabulary is extremely limited, Hodor is otherwise fairly mentally sound, demonstrating the ability to express emotions, carry out orders and comprehend situations just as well as any other simpleminded servant. So why is that he’s only able to utter single words to convey all of his feelings? Well, as some smart Game of Thrones fans have pointed out, Hodor could be suffering from a condition known as expressive aphasia, which is caused by damage to the part of the brain responsible for speech.

In 1861, a French neurologist named Paul Broca met a patient with symptoms nearly identical to Hodor’s. After his death, it was discovered that the 51-year-old patient, named “Tan” because that was the only word he could say, had sustained damage to the inferior frontal gyrus region of his brain which was determined to be the cause of the condition.

Expressive aphasia can be caused by a number of factors including stroke, malnutrition and head trauma. Given Hodor’s size, it’s probably safe to assume he was getting enough to eat, but he does have a noticeable scar on the side of his head which would seem to indicate some sort of head trauma he sustained in the past that could have brought on the condition.

2. The Crazy Seasonal Patterns Could Be Caused by Winds, Oceans and Currents

Prevailing winds and ocean currents can have a large impact of a planet’s climate. Currents like El Niño and La Niña are subject to cyclical variation and can alter regional climates over the course of several years. And Canada’s warm Chinook winds are quite hard to predict but nonetheless have quite a significant effect on the weather experienced in the Prairies.

Although we don’t have quite as detailed a description of the planet in Game of Thrones as we do of Earth, after some science geeks examined a few features such as the locations of the icy poles and warm deserts, they determined that Westeros could be part of a world that’s roughly 10 percent wider than the Earth. So it’s within reason to assume that this fictional world could contain taller mountains, stronger prevailing winds, larger oceans, and more powerful currents—all of which could contribute to the intense and unpredictable weather patterns seen in the series.

1. Dire Wolves Were Actually Real

In Game of Thrones, dire wolves seem to be an endangered species of wolf that can grow to be as big as a small horse but are seldom seen south of the wall. Believe it or not, this species of animal is actually 100 percent real. Though they didn’t grow quite as big they do in the series, dire wolves, or Canis dirus, roamed the forests of North America for roughly 15,000 years and hunted prey like horses and bison. Though they were built heavier with broader chests than modern wolves, this factor eventually led to their extinction as they found it more and more difficult to compete with wolf species that were faster and better equipped to take down more nimble prey.