Scientists have announced hints that the Universe is actually relatively small — something like 70 billion light years across — with a hall-of-mirrors illusion tricking us into thinking that space stretches on forever.

The thinking is based on observations by NASA’s Wilkinson Microwave Anisotropy Probe (WMAP), which measures temperature ripples in the cosmic microwave background.

Our Universe seems like an endlessly repeating set of dodecahedrons (12 identical pentagons) and space wraps back on itself, says mathematician Jeffrey Weeks. If you exit through one pentagon, you re-enter the same region through the opposite face and you keep meeting the same galaxies over and over again.