With over 700 million downloads, the first Angry Birds game is a testament to the appeal of simplicity. The much-anticipated sequel, Angry Birds Space, which launched on Thursday, looks just as simple, and as freakishly enjoyable.
But there is one big difference between the original and its high-flying sequel: Angry Birds Space is being billed as a tool for educating people about physics.
The original Angry Birds allows players to slingshot a variety of ornery avians at oblate green pigs. The pigs have absconded with birds' eggs, hence their anger.
Angry Birds Space incorporates an element of interplanetary gravity. The developers collaborated with NASA to "teach people about physics and space exploration through the internationally successful puzzle game," according to NASA's recent press release.
Peter Vesterbacka, the chief marketing officer of Rovio, which made the game, said in the release that the company couldn't "wait to work with [NASA] on creating more compelling educational experiences."
But is that really true? Is there any educational value in Angry Birds Space?
Before we explore this question, though, let's admit that Angry Birds Space is a game, foremost, and a fun one at that. Perhaps there doesn't have to be any more of a justification to play it, and maybe the excuse of educational value is unnecessary.
And let's give credit where it's due. The claim that the new game appropriates the concept of microgravity – the kind of low gravity that affects objects in orbit, like at the International Space Station – is pretty much true. Also, the game illustrates how objects – in this case, the birds – launched in a straight line will curve their trajectories in the presence of massive bodies. So far, so good.
But when you add audible TNT detonations in space, plants subsisting without carbon dioxide on otherwise forlorn moons, an inexplicable presence of wood and concrete, and the stormy purple vortex at the stroyline's beginning, the educational value of the game falls off dramatically.
The game exhibits more serious problems too, namely, physical impossibilities. Rhett Allain, Associate Professor of Physics at Southeastern Louisiana University and Blogger for wired.com, pointed some of these out.
In the game, the slung birds enter the gravitational fields of tiny pocked moons and plummet toward them. According to Newton's Law of Gravitation, the moons must be extremely massive in order for the birds to move as fast as they do. But the moons aren't all that much larger than the birds themselves. This means that they would have to be extremely dense. Allain calculates one moon's density to be about 7 billion kg/m3 , closer to the density of a white dwarf than that of a moon.
Also, if the moons had real gravity, then all objects caught in their fields – which in the game are portrayed as glowing pellucid disks – would accelerate towards the surface. It's hard to say if the birds follow this law, since they go through so many other inexplicable motions. But the debris they collide with clearly do not. Allain demonstrated that in the game, rocks actually slow down during their free-fall to the moons' surfaces.
And why are those moons sitting still, exactly? In space, they would not only gravitationally interact with the wayward birds, but also with each other. If intentional, it was clever for the developers of Angry Birds Space to lock the moons in place. The conundrum of three or more bodies gravitating towards one another still perplexes physicists. They call it the n-body problem. Obviously, n-body gravitation occurs, but we have no way to theoretically explain it. Even the current models that can approximate this motion are astoundingly math-intensive.
Criticizing an extremely fun and successful video game for its inaccuracy is easy, if not curmudgeonly. But if you're going to look to Angry Birds Space for educational value, you should know that its physics is about as accurate as its ornithology.