09Nov2019

Everything We Know About The Universe’s Shape Might Be Wrong

Everything we think we know about the shape of the universe could be wrong. Instead of being flat like a bedsheet, our universe may be curved, like a massive, inflated balloon, according to a new study.

Scientists Close To First Sighting Of Milky Way Black Hole

That’s the upshot of a new paper published today (Nov. 4) in the journal Nature Astronomy, which looks at data from the cosmic microwave background (CMB), the faint echo of the Big Bang. But not everyone is convinced; the new findings, based on data released in 2018, contradict both years of conventional wisdom and another recent study based on that same CMB data set.

If the universe is curved, according to the new paper, it curves gently. That slow bending isn’t important for moving around our lives, or solar system, or even our galaxy. But travel beyond all of that, outside our galactic neighborhood, far into the deep blackness, and eventually — moving in a straight line — you’ll loop around and end up right back where you started. Cosmologists call this idea the “closed universe.” It’s been around for a while, but it doesn’t fit with existing theories of how the universe works.

So it’s been largely rejected in favor of a “flat universe” that extends without boundary in every direction and doesn’t loop around on itself. Now, an anomaly in data from the best-ever measurement of the CMB offers solid (but not absolutely conclusive) evidence that the universe is closed after all, according to the authors.

The difference between a closed and open universe is a bit like the difference between a stretched flat sheet and an inflated balloon, Melchiorri said. In either case, the whole thing is expanding. When the sheet expands, every point moves away from every other point in a straight line. When the balloon is inflated, every point on its surface gets farther away from every other point, but the balloon’s curvature makes the geometry of that movement more complicated.

The conventional model of the universe’s inflation, Melchiorri said, suggests that the universe should be flat. Rewind the expansion of space all the way to the beginning, to the first 0.0000000000000000000000001 seconds after the Big Bang, according to that model, and you’ll see a moment of incredible, exponential expansion as space grew out of that infinitesimal point in which it began. And the physics of that superfast expansion point to a flat universe. That’s the first reason most experts believe the universe is flat, he said. 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.

But that might end up being necessary, the authors wrote in the new study. That’s because there’s an anomaly in the CMB. The CMB is the oldest thing we see in the universe, made of ambient microwave light that suffuses all of space when you block out the stars and galaxies and other interference. It’s one of the most important sources of data on the universe’s history and behavior, because it’s so old and so spread throughout space. And it turns out, according to the latest data, that there’s significantly more “gravitational lensing” of the CMB than expected — meaning that gravity seems to be bending the microwaves of the CMB more than existing physics can explain.

Some cosmologists said there were reasons to be skeptical. Melchiorri also agreed that the closed-universe model would raise a number of problems for physics. “I don’t want to say that I believe in a closed universe,” he said. “I’m a little bit more neutral. I’d say, let’s wait on the data and what the new data will say. What I believe is that there’s a discrepancy now, that we have to be careful and try to find what is producing this discrepancy.” Source: Live Science

Read previous post:
China’s Simulated Weightlessness Experiment For Long-Term Space Travel

Thirty-six healthy male volunteers lay on beds with their heads...

First Child Born In Space Will Equal Neil Armstrong and Yuri Gagarin

HUMANS looking back at the history of spaceflight hundreds of...

Who Was Galileo??

Italian astronomer Galileo Galilei provided a number of scientific insights...

Close