Physicists believe that the universe is flat, and evidence of residual light from the Big Bang and the rate of expansion of the universe at various locations indicate this.David Spergel, a theoretical astrophysicist and professor emeritus of astrophysics at Princeton University , has studied the shape of the universe for decades. In a 2003 study published in The Astrophysical Journal, Spergel measured the roughness of the cosmic microwave background (CMB), the light left over from the Big Bang.
“A flat universe corresponds to a universe without energy,” Spergel said.
The new research, published in the journal Physical Review D, found that the universe, within a 0.2% accuracy margin, was flat. The data indicate that the spatial curvature is zero, which means that the universe is within statistical uncertainty – infinite.