The shape of the universe is a matter of debate in physical cosmology over the local and global geometry of the universe which considers both curvature and topology, though, strictly speaking, it goes beyond both. In practice, more formally, the debate seeks a 3-manifold that corresponds to the spatial section (in comoving coordinates) of the 4-dimensional space-time of the universe.
The recent Wilkinson Microwave Anisotropy Probe (WMAP) measurements have led NASA to state, "We now know that the universe is flat with only a 0.5% margin of error." Within the Friedmann–Lemaître–Robertson–Walker (FLRW) model, the presently most popular shape of the Universe found to fit observational data according to cosmologists is the infinite flat model, while other FLRW models that fit the data include the Poincaré dodecahedral space and the Picard horn.
Read more about Shape Of The Universe: Introduction, Local Geometry (spatial Curvature), Global Geometry
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“Thir dread commander: he above the rest
In shape and gesture proudly eminent
Stood like a Towr; his form had yet not lost
All her Original brightness, nor appear’d
Less than Arch Angel ruind, and th’ excess
Of Glory obscur’d: As when the Sun new ris’n
Looks through the Horizontal misty Air
Shorn of his Beams, or from behind the Moon
In dim Eclips disastrous twilight sheds
On half the Nations, and with fear of change
Perplexes Monarchs.”
—John Milton (1608–1674)
“Man is only a reed, the weakest in nature; but he is a thinking reed. There is no need for the whole universe to take up arms to crush him: a vapor, a drop of water is enough to kill him. But even if the universe were to crush him, man would still be nobler than his slayer, because he knows that he is dying and the advantage the universe has over him. The universe knows nothing of this.”
—Blaise Pascal (1623–1662)