Anto I. Lonappan

Boiling milk develops a trembling skin. By watching its movements, you can guess the strength of the fire beneath the pot and the fat content of the milk. In a similar way, astrophysicists peer into the ancient microwave radiation — the oldest light that has reached us from an era when the universe was only 380,000 years old.

Eight sky maps taken by different detectors of the Planck telescope resemble eight road atlases of the same city drawn by different cartographers. Each atlas is rotated by its own angle: one cartographer held the tablet slightly tilted, another slightly turned. If you overlay the atlases, the streets won't align. But if you know how each atlas is rotated, you can align them perfectly.