Scientists Say the Universe Might Be a Giant Donut — And Here’s What That Actually Means

Did you know that there is a theory about the shape of the universe that suggests it might resemble a giant donut? That’s a real idea in science called a 3‑torus topology. It is a concept that theorizes the universe is looped all around, but still flat in a geometrical sense.

In other words, scientists believe that the universe follows Euclidean geometric rules, such as the sum of all angles of a triangle being 180 degrees, parallel lines never intersect, and that straight paths remain straight. However, they think that space might connect back on itself, so if you traveled far enough in one direction, you could end up right where you started, and you would not hit any wall or limit, like traversing inside a giant donut.

What Is a “Donut-Shaped” Universe?

In the mathematical sense, a donut-shaped universe can also be flat, which means that all the Euclidean geometric laws still apply. But to imagine it better, think of a piece of cardboard that is flat, and that is how the universe is still inside the donut.

If you draw parallel lines in this cardboard, they should never meet, and the triangles should have their inside angles add up to 180 degrees. Scientists believe this is how the universe works on the grandest of scales.

Now, imagine rolling up that cardboard, making a cylinder, then connecting both ends, you will end up with a donut-shaped cardboard. It still works the same, but since both ends are connected, if you travel one side far enough, you will loop back to where you came from. That is the simplest explanation of what a donut-shaped universe is for a non-physicist to visualize, but let’s look at how this idea came up.

Read more: Science News Explorers

How Do Scientists Look for a Donut Shape?

The Universe Could Be a 3D Donut and Not Infinite Study Suggests

The donut-shaped universe theory, also known as the toroidal universe, says that the universe might be finite and loop back onto itself. Since mathematically, this is a valid topology, scientists have tried studying ancient light from the time the Big Bang first exploded, called the Cosmic Microwave Background (CMB).

If space truly loops back, the same light patterns should appear from different directions in the universe. Scientists have long sought to identify these matching patterns, but to no avail; evidence was still lacking. However, this theory still stands, and has not yet been fully ruled out because it is still a valid possibility.

Finite But No Edges

A donut-shaped universe will be finite and have no edges, just like how on Earth, if you go from one side far enough, you will end up in the same place, but still the planet is not infinite. We could circle back the whole universe without ever reaching an end, or falling off an edge.

In other words, the universe looks so big and infinite to us because it might be shaped as a donut or torus, and if we had the capability to look in one direction as much as possible, we could see the back of our planet.

Read more: Wikipedia

Why It Matters

If the universe is really shaped like a donut and continuously loops, then some of our understanding of how the universe began and how it could end might be wrong. The Big Bang may have happened inside a compact shape that has been stretching forever. The whole universe, just like the cardboard analogy above, might be folded in on itself from the very start.

And in the end? There might not be one because the continuous expansion of a donut-shaped universe could never hit a wall or edge. This means we are stuck in a cosmic loop that will never end, unless it begins shrinking and collapsing into its own self, creating a singularity, which is explained more in a theory called the Big Crunch.

What If the Universe Was Shaped Like a Donut?

Author's Final Thoughts

The idea that the universe is donut-shaped is both funny and fascinating. However, it is grounded in real mathematical calculations and probabilities, and more importantly, it still follows the rules of physics that we know. So, though we have not found proof yet, we can’t just rule it out, leading scientists to continue studying the little clues left behind at the beginning of the universe.

Read next: Scientists Explain: The Earth Is Not Flat, But the Universe Might Be