Andrew Coleman
Teach physics with the popular video game Portal

Have you heard of Portal? It’s a fast, fun and extremely popular game — available via Steam for PCs or Macs — that’s relevant to a number of subjects especially physics. 

The game marries first-person game play with intriguing puzzles using one deceptively simple gameplay mechanic — the portal gun. The portal gun can produce two things, an orange portal and a blue portal. What goes into the orange portal comes out the blue portal, and vice-versa.

In the game, you are a test subject who must perform experiments, eerily similar to a rat in a maze, while observed by a computer with a disembodied voice. You solve the puzzles by teleporting yourself and inanimate objects from one flat plane to another using the portals. To maneuver through the test chambers, you’ve got to use your critical thinking skills and  understand basic physics concepts to employ the portals successfully.

A physics lesson for students

Portal’s puzzles provide excellent problem-based learning experiences for physics classrooms. For example, students can learn about projectile motion in the game.

In one puzzle, players need to get across a wide canyon inside a room. The only tools at your disposal are the room itself, the portal gun and your critical thinking skills. You are not allowed to place a portal on the other side of the canyon. So how will you cross it? Pause and think about it: How would you cross the canyon? Figure it out yet?

Hint: To answer this question, you need to understand conservation of momentum and how acceleration during freefall works. In this case, you would have been introduced earlier in the game to a mechanic in which momentum is conserved through portals.

Give up? Here’s the answer: You need to place a portal on the ceiling above the canyon and a portal on the floor of the canyon directly below the first portal. You then jump into the canyon — and the bottom portal — which results in falling out the top portal. You will then freefall from the top portal to the bottom portal several times, constantly accelerating.

Once you have built up enough speed, you switch the top portal to a wall on the side of the room you started on (remember, you can’t place any portals on the other side of the canyon). When you enter the portal on the floor of the canyon, you come out of the portal on the wall, but your vertical velocity has been converted to a horizontal velocity powerful enough to propel you across the canyon to the other side.

The real problem to solve, once you figure that mechanic out, is how many times you need to freefall through the portals to get to a velocity that will get you to the other side of the canyon.

As the teacher, you can do one of two things: Find the distance from the wall to the other side through experimenting on your own in the game, then give that number to your students and have them calculate the time in freefall required to reach the target velocity. They can check their answers by performing the experiment in the game. Or you could have your students do the experiment to determine the distance across the canyon by finding the minimum freefall time.

And that’s just one of many physics and critical-thinking applications of Portal.

Now for the drawbacks: Students will need to take time to learn how to play the game, and those with little to no experience with first-person gameplay might struggle. You will also need to have a computer with Portal installed for every group. 

Fortunately, Valve offers an educational version of the game to schools for free. Through the Teach with Portal program, you can even create your own puzzles or use puzzles created by other teachers.

Use Portal in teacher education

Before we had Portal, one of the frequent struggles we had in our teacher education program was providing concrete examples of student-focused lessons with appropriate scaffolding. Imagine our delight when we discovered a game that directly demonstrates this process at work.

There’s a popular aphorism in gaming circles: A good game has a good tutorial, but a great game is the tutorial. Portal is one of those. Instead of telling you how to play the game, it allows you to start and slowly introduces new mechanics with very specific and planned sequences. In the context of a physics lesson, the player has to experiment to figure out the correct solution to each puzzle to advance in the game.

Portal eventually releases you into an uncontrolled environment and asks you to use the skills you've learned in new situations to complete the game. This process — giving students a controlled environment to experiment and practice skills, then asking them to apply those new skills in an unfamiliar setting — is exactly the kind of constructivist teaching that has been proven most effective. And that’s a great lesson for teacher candidates. Letting preservice teachers play Portal gives them a fun demonstration of how this type of lesson works in practice with a relatively low time commitment.

Consider the momentum lesson above. It involves the type of outside-the-box solution that inspired the game’s motto: “Now you’re thinking with Portals.” But the game also helps the player get to the solution by scaffolding their learning up to that point.

There is a room early on in the game that has a long gap that players need to cross via the conservation of momentum solution discussed above. Instead of telling you exactly what to do, the game draws attention to where you need to place a portal by moving a section of the wall above you. Seeing that, most players put a portal on the moved wall, jump through and see what happens. Usually that’s enough to get them to consider looking to the ceiling the next time to see if the same solution is workable in future situations.

How might this work in teacher education? As teacher candidates play through the game, coach them to ask themselves in each of the testing rooms (which make up the first half of the game) what lesson the designers are trying to teach the player, how the lesson is scaffolded and how the player can use it in the second half of the game.

Andrew Coleman and Matthew Jackson are teacher candidates enrolled in the University of Michigan’s master’s and certification program.

Get more ideas on how to use games to teach critical thinking on the EdTekHub