Is dark matter real or just a convenient hypothesis? Although it was first proposed almost a century ago, physicists have yet to uncover its true nature. Scientists from the Nicolaus Copernicus University are investigating the phenomenon using atomic clocks.

The author presents a sketch of the history of concepts and imaginative geography of the lands located in the hereafter: earthly and heavenly Paradise, Purgatory and Heaven. He reaches back to the origins of these images in ancient Eastern cultures, the culture of Antiquity, and patristic writings. He traces their development throughout the Middle Ages to the time of Dante, whose La Commedia sanctioned the separation of the hereafter into topographically located Hell, Purgatory and Paradise.