Science & Technology

In Outer Space, There Is No Up or Down

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Ever stare into the night sky and wonder what's going on up there? Ask a cosmologist and their response would likely be "Up where?" There's probably no such thing as "up" in outer space. Or "down," for that matter. Feeling dizzy?

So Random

According to a study published in September 2016, the universe probably doesn't have a preferred direction. That is, there is no up, down, right, left — no "correct" orientation at all. The researchers from University College London and Imperial College believe the universe is isotropic, which means that it looks the same no matter how you view it.

The researchers estimate that there's only a 1-in-121,000 chance that the universe has a preferred direction — the best evidence yet for an isotropic universe. They were able to determine this by looking at the cosmic microwave background (CMB), the ancient afterglow left over from the Big Bang. The team used the European Space Agency's Planck spacecraft, which collected data from 2009 to 2013, to give us the most precise measurements of the CMB yet.

Let's imagine for a second that the universe does have a "right" direction —that is, it's anisotropic. This would mean that the universe is expanding at different speeds in different directions from some central point or specific axis, thus pulling and stretching the CMB into identifiable shapes and patterns. The data showed that the CMB is random noise, and probably doesn't include patterns or other clues that would point toward an anisotropic universe. Basically, the universe is a well-blended mixture of space stuff that grew from a homogenous universe soup.

Expedition 38 crew members pose for an in-flight crew portrait in the Kibo laboratory of the International Space Station on Feb. 22, 2014.

Close Call

The idea that the universe is isotropic is definitely a relief. "It's a much more comprehensive analysis than in previous cases," Anthony Challinor, a cosmologist at the University of Cambridge in the United Kingdom who was not involved in the work, told Science Magazine. "The question of how isotropic is the universe is of fundamental importance." The work cosmologists do, and have done, rests on the assumption that the universe is isotropic. If it weren't, then we could just go ahead and throw our understanding of the evolution of the universe out the window. Phew.

"For the first time, we really exclude anisotropy," Daniela Saadeh, cosmologist at University College London, tells Science. "Before, it was only that it hadn't been probed."

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Written by Joanie Faletto January 3, 2018

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