When 3D movies first arrived in the 1950s—and were then seriously improved in the 2000s—the whole thrill was that these films were more "life-like".
Of course, you can be the judge on whether there's anything life-like about Iron Man flying over your head at 400 km/h while he escapes an alien plasma blast, but ...
While normal movies are shown on a flat screen (two dimensions, or 2D), we live in a world of three dimensions. Even if it's an illusion, 3D is a more accurate representation of what we live in. It is more like life.
For centuries, the world's leading minds have all agreed that three dimensions are not only crucial to life, but gravity, orbits, atomic structures... you name it.
But now, a new paper by physicist James Scargill at the University of California is challenging all that. He argues that a 2D universe could have gravity, a cosmos, and yes, living things. This is basically like saying that a universe could exist across a giant sheet of paper.
The magical +1
A 2D universe? How? First, let's explain a bit about the universe that we do live in ... with a graph!
What we call 3D actually has four dimensions, or 3 +1D. You have the x, y, z dimensions that you see above — those are length, width, and height. But there's also the dimension of time. Every second that passes is a measurement of that dimension.
When you think about how literally everything in our life requires the passage of time — growing, learning, travel — time is one magical +1 dimension! Without it, the universe would just be a bunch of cubes and spheres doing nothing. But with it?
The universe is alive with motion, reactions, and complexity.
Flat mind blown
Meanwhile, the flat universe Scargill is talking about is not 2D, but 2 +1D.
You've got the length (x) and height (y) that you see here, plus time.
According to Scargill, these dimensions together could be enough to create forces like gravity and a cosmos. And they could also create their own versions of the tiny building blocks of life, like atoms.
2D? Could be...
As you might have noticed, could is the important word here. Scargill hasn't found a 2 +1D universe. He's just offered proof that it's possible. So why are we gabbing about something that hasn't been found?
Well, you know what only existed as an idea on paper until a few months ago? Black holes. It wasn't until we finally got an image of one recently that we had photographic evidence that they were there. Truth is, all kinds of things exist that we can't see. Yet, anyway.
What do you think a 2D universe would be like?