Weird Fact: After years of hypothesizing, scientists finally have proof that the shape of the universe is flat.
During the 20th century, cosmologists theorized that the universe must either be flat – or curved:
- A flat universe would be INFINITE. If you left Earth in a rocket ship and flew off in a straight line, you would keep on going, forever. And ever. And ever.
- A curved universe would be FINITE. Your straight-line rocket ship flight would (eventually) bring you right back to where you started… As if the universe looped back on itself like a doughnut or was curved like a sphere.
The Galaxy Survey
To find out which theory was true, cosmologist Dr Brian Boyle used cutting-edge technology to create a 3D map of the universe. That’s no small task. Then he studied the galaxies’ interactions with each other to estimate the weight of all the galaxies on the map.
Remarkably, Boyle found that the universe is much lighter than anybody had imagined. Too light, in fact, for there to be enough gravity to pull it into a curved shape. So he concluded that the universe must be flat.
Cosmic Microwave Background Radiation
This conclusion was later confirmed by further groundbreaking evidence provided by the study of Cosmic Microwave Background Radiation as it passes by the Earth.
The CMBR is a wall of radiation created by the Big Bang explosion which occurred some 14 billion years ago. The radiation is everywhere – you can even see it when you get the snowstorm picture on your TV. In terms of mapping outer space, it’s all we can see when we look out at the very edge of the known universe (which is why, in time, the universe will always be finite).
By monitoring the “black spots” in the radiation as it passes by Earth, scientists can see exactly what space the CMBR has traveled through so far and measure the microwave background fluctuations. And it has revealed that the universe is flat within a 0.5% margin of error.
A flat universe gives us an infinite universe, in terms of space. And with accelerating expansion, the universe will always be bigger than we can directly observe.