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Imagining impossible – Physics in the virtual reality

Image Description: Article banner. A cartoony image of a man wearing a VR headset. Purple miasma flowing out of it with equations inside of it. He seems to be manipulating two disks with his hands. End Description Image Description: Mobile version of the article banner. A cartoony image of a man wearing a VR headset. Purple miasma flowing out of it with equations inside of it. He seems to be manipulating two disks with his hands. End Description

Can you explain the world around you?

Stop what you are doing and conduct a little experiment. Take off your right sock, scrunch it up, and throw it. Did it go far? Did it land where you thought it would? Are you now annoyed you have to hop along to retrieve your sock? Well, go and grab it again and repeat the experiment. This time I want you to watch the path it takes through the air. Can you describe the shape it makes? Can you explain why it makes this shape? Can you think of an engineering application where knowing where it will land is useful?

If we can understand the physics of a falling sock – maybe we can extend this understanding to dropping medical supplies from an airplane, or launching satellite into space? Indeed, scientists have been throwing things about and trying to explain their motion for millennia. If Aristotle lobbed a sandal across his courtyard, he might have said that a force causes it to move forwards as a result of the air pushing it. If a young Galileo launched his moccasin across his observatory, he might have said his launching force must be larger than the force of gravity. You might even agree with these ideas – they seem sensible after all.

 

Image Description: A cartoony man holding a VR headset. Inside of the goggles theres a real life photo of a man standing in front of a giant fan. End description.

^ Jed Marshall

 

Both of these above ideas are wrong. If you thought that gravity takes time to act before your sock falls, you are wrong. If you thought whilst the sock was moving up there was an upwards force, you are wrong. If you thought the sock was stationary and it might instead be the Earth moving up you are… well you might be right but let us forget such an outlandish idea for now. These are all what teachers would call alternate conceptions – ways of explaining observations that do not agree with the scientific consensus.

The right answer (or the most sensible answer) is that there is one constant force, the force of gravity, and it constantly acts downwards on the sock. This force causes it to move in an arced motion. There is a second force, Air Resistance, but to keep it simple we will simply ignore it. The problem with the ‘correct’ answer, as I find everyday as a teacher, is that it is very hard to convince students that it is correct.

I can ask you to imagine that we ignore air resistance, but short of suffocating us all with a huge vacuum, I cannot show you. I can ask you to imagine in which direction an object would accelerate if there were a force acting upwards, but short of inventing an anti-gravity machine, I cannot show you. In our classrooms, we are trapped by the limits of our own real-world experiences and imaginations – or so we thought…

Using Virtual Reality to allow students to experience the impossible – worlds without air resistance, or worlds that have incorrect physics.

Image Description: A gif of a cartoony hand almost holding a floating apple. Arrows appear on the sides of the apple. End Description.

Virtual Reality (VR) is a technology that allows you to enter, and interact with, a virtual world. I worked closely with a developer, Joe Hart, to make a VR physics game that allows students to experience their alternate conceptions around thrown objects. Our reason for this is based on the following hypothesis: people sometimes build their understanding of the world through experience – so what happens if they are free to experience their ‘incorrect’ conceptions?

The game we made allows you to control a character as you make them jump across a small river. After the third jump, time freezes and you are asked to identify in which direction the force is acting. When time resumes the game assumes you are correct – and shows you what would happen if what you thought is true, was true.

For example if you think the force is acting ‘backwards’ in the opposite direction to the motion, when time is resumed, they would accelerate off in that direction. The students who tried this at Alexandra Park School could not help but laugh, it feels wrong, and it can even be frustrating that the character does not make it across the river.

By using innovative technology to allow students to experience the impossible – worlds without air resistance, or worlds that have incorrect physics, we hope that students can experience their alternate conceptions. Discussion is a powerful tool when exploring our ideas of how the world works and this game can help facilitate deep and meaningful talks between teachers and their students.

Our plans for the future are to continue our development of VR games with our Rolls Royce Science Prize. We also have many other ideas in the pipeline – to get something into orbit around a planet you do not need to go up, you need to go sideways. What if in VR you can stand on a tiny planet, throw a ball, turn around and catch it? An exciting future of experiencing the impossible awaits!

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WRITTEN BY

Jed Marshall
Head of Physics, Alexandra Park School

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