Cosmology ’ s standard model posits an infinite flat universe forever expanding under the pressure of dark energy .
First-year data from the Wilkinson Microwave Anisotropy Probe ( WMAP ) confirm this model to spectacular precision on all but the largest scales ( Bennett et al . , 2003 ; Spergel et al . , 2003 ) .
Temperature correlations across the microwave sky match expectations on scales narrower than 60 ^ { \circ } , yet vanish on scales wider than 60 ^ { \circ } .
Researchers are now seeking an explanation of the missing wide-angle correlations ( Contaldi et al . , 2003 ; Cline et al . , 2003 ) .
One natural approach questions the underlying geometry of space , namely its curvature ( Efstathiou , 2003 ) and its topology ( Tegmark et al . , 2003 ) .
In an infinite flat space , waves from the big bang would fill the universe on all length scales .
The observed lack of temperature correlations on scales beyond 60 ^ { \circ } means the broadest waves are missing , perhaps because space itself is not big enough to support them .

Here we present a simple geometrical model of a finite , positively curved space – the Poincaré dodecahedral space – which accounts for WMAP ’ s observations with no fine-tuning required .
Circle searching ( Cornish , Spergel and Starkman , 1998 ) may confirm the model ’ s topological predictions , while upcoming Planck Surveyor data may confirm its predicted density of \Omega _ { 0 } \simeq 1.013 > 1 .
If confirmed , the model will answer the ancient question of whether space is finite or infinite , while retaining the standard Friedmann-Lemaître foundation for local physics .