5 Science Experiments Inspired by Harry Potter

J.K. Rowling minces no words when it comes to her memories of beakers and chemical equations. “Chemistry was my least favourite subject at school, and I gave it up as soon as I could,” she recalls. Rowling hated the subject so much that she made Severus Snape—Harry Potter’s archenemy—the Potions Master at Hogwarts.

Yet when writing the Harry Potter novels, Rowling became engrossed in real-world inspirations for the potions she was creating. Part of her “found Potions quite as interesting as Snape did,” and she delved into the history—both real and fictional—of various plants and tinctures. When Harry was bitten by Voldemort’s snake, Hermoine used Dittany, a magical plant, to heal him. Its origins can be traced to Origanum dictamnus, a small, velvety herb that grows only on the Greek island of Crete. Centuries ago, it was used as a poultice for healing wounds.

In an NSTA presentation earlier this year, Alan McCormack, a professor emeritus of science education at San Diego State University, explained that teachers can make use of student interests like the Harry Potter books to boost engagement and tap into students’ imagination and creativity. There are many ways to do this.

Harry Potter’s Invisibility Cloak

Harry Potter famously used an invisibility cloak—described in The Philosopher’s Stone as “strange to the touch, like water woven into material”—to sneak around, eavesdrop, and escape detection in dangerous situations.

Could an invisibility cloak work in real life? Students may think it’s impossible, but this is an opportunity to talk about light refraction, which can be observed when light passes from one medium to another, such as from water to air. Here’s a simple experiment you can do with younger children: Place a penny underneath a clear cup, and let the students see the penny. When you fill the cup with water, the penny will disappear. Your students will have to be viewing the cup from a certain angle—not too high or they’ll see the penny from above.

It isn’t gone, of course. As water enters the cup, it bends the light reflected from the penny, making the penny appear in a different location—a spot that’s not visible from the students’ perspective.

Alastor Moody’s Magical Eye

After losing his eye in battle, Professor Alastor Moody received a magical replacement. Described as “electric blue,” Moody's eye could see through any material, from doors to walls and even Harry’s invisibility cloak.

You can use a Rochester cloak to “see” through solid objects. Arranging four convex lenses in a straight line will cause light to bend between them. This creates a “tunnel” between two of the lenses—if you place your hand in the right spot, you’ll be able to see right through it.

The Pensieve

In the Hogwarts headmaster’s office sits a large basin filled with a shimmering liquid. “One simply siphons the excess thoughts from one’s mind, pours them into the basin, and examines them at one’s leisure,” explains Dumbledore. Generations of wizards can store their memories in the pensieve, creating a library of experiences for future reference.

How are memories stored? How are they recalled? Can they be extracted and altered? This is an opportunity to delve into the science of memory and give your students a lesson in brain anatomy and different types of memory (working, short-term, and long-term). There are also dozens of experiments students can conduct on memory to investigate how reliable it is over time or to test strategies that can improve memory recall. You can start with a Potteresque example, such as Neville Longbottom forgetting where he put his toad, and use that to launch an experiment on whether singing could boost his memory.

Spells and Potions

Is there a scientific basis for magical potions? In The Science of Harry Potter: How Magic Really Works, science journalist Roger Highfield gives us a useful clue: Because plants can’t run or hide, they’ve developed a “fearsome range of chemical weapons to deter, maim, and even kill insects and animals that eat them.” You can ask your students to think about ways in which plants protect themselves, using real examples such as dieffenbachia, which uses idioblasts to release paralysis-inducing enzymes when eaten.

The spells in the books likewise have some basis in reality. In The Prisoner of Azkaban, Professor Remus Lupin taps a kettle with his wand, instantly heating tea. While boiling is usually caused by heat, it can also be simulated with pressure, as this science experiment demonstrates: By withdrawing the stopper on a syringe filled with water while covering the tip (be sure to yell “Incendio!” for dramatic effect), you decrease the pressure inside, turning liquid into gas. Bubbles of water vapor will appear, making it appear as though the water is boiling.

Wizards will often use invisible ink to ensure that their diaries remain private or to send secret messages to others. When Hermoine finds Tom Riddle’s diary, she casts a revealing charm on its blank pages, hoping to expose any hidden writing (although to no avail). To recreate this as a science experiment, all you need is a lemon, water, and a light bulb or other heat source. The same process that makes bananas and avocados turn brown—oxidation—also gives invisible ink its magic.

The Sorting Hat

Upon arriving at Hogwarts, students are assigned to one of four houses: Gryffindor, Hufflepuff, Ravenclaw, or Slytherin. For over a thousand years, giving students their housing assignments was the job of the Sorting Hat, which divined a wizard’s potential and declared which house they would join.

Card-sorting can help younger students practice early math skills such as categorizing, pattern recognition, and observation. It also builds language skills as students describe what they see. A fun activity is to sort cards by pulling them from a hat. This can also be done with shapes and colors, animals, or rocks—nearly any set of objects that can be categorized can be adapted into a sorting game.

Magical devices like the Sorting Hat can be used to build wonder in students, introducing them to scientific concepts that would otherwise be too abstract and difficult to comprehend. Here are a few other magical elements of the Potter books that can be adapted for use in science lessons: