The Physics of Harry Potter

Some of the stories that people read are based on making the impossible possible.  These reality defying tales are much more enjoyable to read when the laws of physics, as we know them, are not necessarily adhered to, and the characters in the story can bend or even break them.  Such is the case for J.K Rowling’s Harry Potter books.  The story of an ordinary boy who discovers that he is a wizard thrusts the reader into a world where the impossible is not only performed but is easily accepted and expected by the inhabitants of the world.  From a scientific point of view, Harry Potter’s world presents a very enjoyable case at examining the apparent lack of laws of physics.  The stories defy some of the most basic laws but are not challenged because they are all done so under the premise of “magic.”  Throughout the seven Harry Potter books, however, the natural laws of physics are violated many different times but are done so in a way that it only adds to the plot of the stories overall. What's a world without illusions in movies and computer games?

One of the most fundamental laws of physics that is defied on a routine basis in the Harry Potter universe is that law of gravity.  As common science will tell us, gravity is the force that pulls objects to the ground because of the mass discrepancies between the objects on planet Earth and the immense mass of the universe and of the planet itself.  In general, one would expect inanimate objects, such as broomsticks, candles, books, cars, or people to be pulled back to the ground when they are in the air.  The magical community of Harry Potter, however, laughs at this concept and openly defies it.  Take the sport of Quidditch for example.  In this sport, broomsticks propel individuals through the air at lightning speeds as the players play an exciting yet dangerous game that is the wizarding world’s favorite sporting event.  What one must realize in terms of the ability for a broomstick to fly is “given a certain amount of force, a broom could be thrown into the air but there would be no way to alter its course.  Once you add a ride to the broom, the force to generate ‘flight’ would be much greater,” (Resnick).  

Another use of flight that is clearly overlooked and defies physics is the ability for certain animals in the wizarding world to achieve flight based on incorrect proportions.  In the fourth Harry Potter book, a giant carriage is flown through the air by winged horse like creatures that are tethered together.  The book makes special note to say the creatures are very large but were tied quite closely to draw the carriage.  Conventional wisdom tells us that this also cannot be true.  Newton’s 2nd Law of Motion clearly states that force equals mass times acceleration.  Based on the creature’s large mass, added to that of a carriage that carried multiple students and a half-giant headmistress, the force need to be generated by the creatures is immense.  The major issue becomes the 3rd Law of Motion for this type of flying.  For every action there is an equal and opposite reaction ergo the upward force generated by the creature’s wings (which would have to be huge to generate enough force for the creatures themselves to fly) would have to be strong enough to overcome the downward force that the animals themselves and the carriage would generate thanks to gravity.  Once this gravitational force took hold, “the carriage would become a greater downward force than the forward force given by the horses,” (Resnick) and they would fall (quickly) to the ground.

Flying is not the only means of travel that defies convention physics in the Harry Potter world though.  Teleportation is another quick and, usually, painless way of moving around the world for the trained wizard or witch.  In the books, people can either freely teleport from one location to another through a process called apparition or they can move be transported by touching an object known as a port key.  Either way, this mode of transportation defies physical law.  The process is so instantaneous that those undergoing it must be traveling near or at the speed of light, which is only theoretical potentially impossible according to scientific research currently.  The amount of energy that would be transported into the individual that is traveling under this premise is immense.  The amount of force and energy needed to move at a speed that intense is most likely fatal if suddenly thrust into a human body (Highfield). Should such a large amount of energy be transferred to an individual so quickly, it is possible that the amount of heat alone would kill the individual receiving that energy based on the principles of the First Law of Thermodynamics (Kaku).  

One more way in which the laws of physics are defied in the travels of the Harry Potter world comes in the way that the students of Durmstrang travel to Hogwarts.  They travel through a giant wooden ship that submerges underwater to travel then rises up and docks like a normal ship.  The laws of pressure and equalization are clearly violated for this to work, however.  The boards would disallow water from entering the ship upon submerging, however they would not be able to withstand the forces of the water attempting to force itself back into the ship in order to equalize the pressure that was created from the ship submerging underneath the surface (Resnick).  Not to mention, the buoyancy of wood is such that it naturally will float atop of water and not, without the help of a great outside force, break the surface tension and submerge itself without immediately reemerging.  

Though the laws of physics are clearly violated in the Harry Potter world, they are done so in a way that only enhances the plot of the story.  Without these different means of transportation in the stories, a significantly longer time would have been needed for the characters to travel the world and complete their quest to stop the antagonist, Lord Voldemort.  The powers that are used to defy the laws of physics are not abused to such a large extent that they make the stories less enjoyable because all the characters have the ability to break the laws of physics in the same way.  Though science will say the acts in Harry Potter is clearly impossible, they still make for a wonderful, fantastic tale for an individual to read.    

Works Cited

Highfield, Roger. The Science of Harry Potter: How Magic Really Works. New York, NY: Penguin Group, 2002. Print. 

Kaku, Michio. Physics of the Impossible: A Scientific Exploration into the World of Phasers, Force Fields, Teleportation, and Time Travel . New York : Anchor Books, 2008. Print. 

Resnick, Shoval. "Physics and Harry Potter's Magical World." Herald-Mail. 17 Jul 2007: n. page. Web. 5 Apr. 2013. <http://articles.herald-mail.com/2007-07-17/news/25092284_1_quidditch-golden-snitch-harry-potter-books>.