The Bubble We Live In: The Shape of the Universe Found by Astronomers

Everything we think we know about the shape of the universe could be wrong.

What’s the exact shape of the universe? If you ask any cosmologist, they’d probably say that the cosmos we live in is flat, like a massive sheet that is ever-expanding.

An anomaly in the data of the measurement of the Cosmic Microwave Background (CMB)–the weak echo of the Big Bang–offers evidence that the universe constitutes a closed system. The data used in the study were gathered with the help of the Planck space telescope of the European Space Agency.

According to a new study, published in Nature Astronomy, our universe is most likely curved, like a massive inflated balloon, instead of being flat as a sheet. The difference between a closed and open universe is a bit like the difference between a stretched flat sheet and an inflated globe, Alessandro Melchiorri, a cosmologist at the Sapienza University of Rome and author of the new study, told Live Science.

In the first billionths of a second after the Big Bang, there was a moment of exponential expansion during which the Universe went from being a simple point to a specific physical space. And the physics of that super-fast expansion points towards a flat universe. For this reason, most physicists opt for that option today.

However, the latest data may prove that everything we thought we knew about the cosmos up until now was essentially wrong.

The recent study offers evidence of a restricted universe and a possible crisis for cosmology suggesting that it could have a curved shape and close on itself just like a sphere, instead of having a flat shape like a stretched sheet.

In any case, everything is (apparently) expanding.

When the leaf expands, each point moves away from any other point in a straight line.

Advertisement

When the balloon is inflated, each point on its surface moves away more than any other point, but the curvature of the balloon makes the geometry of that movement more complicated.

“This means, for example, that if you have two photons and they travel in parallel in a closed universe, [they will] eventually meet,” Melchiorri said. In an open and flat universe, photons, without being disturbed, would travel along with their parallel courses without ever interacting.

All-sky mollweide map of the CMB, created from 9 years of WMAP data. Image Credit: Wikimedia Commons.
All-sky mollweide map of the CMB, created from 9 years of WMAP data. Image Credit: Wikimedia Commons.

The Anomaly

What did experts find? What was the anomaly they discovered?

According to the data of the last measurement of the CMB, the most accurate to date, there is a much greater number of “gravitational lenses” than would be expected, and that means that gravity could be “bending” the microwaves of the CMB much more than current physics is able to explain.

The researchers themselves, however, indicate that, although the evidence is sound, their results are not entirely conclusive.

According to the calculations carried out by the team, the data points to a closed Universe with a standard deviation of 3.5 sigma (a statistical measurement that means that there is a 99.8% chance that the result is not due to a statistical error). However, that is still well below the 5 sigmas that physicists need before confirming an idea.

“If the universe isn’t flat, you have to “fine-tune” the physics of that primordial mechanism to make it all fit together — and redo countless other calculations in the process,” Melchiorri said.

Although the data is sound, refreshing and may help explain the universe, albeit in a much more complicated way,  there is more work to be done, but the debate is served and experts will now look into the possibility of a bubble-like universe, closed and confined, although ever-expanding, like one massive balloon, home to countless stars.

If it turns out that the universe really is shaped like a balloon, astrophysicists would be forced to rethink everything we thought we know about the beginning of the universe and the physics involved.

I wonder what that means for the anti-universe that is said to exist?