Heaven in the stone

For centuries crystallized in the adamantine drawings preserved in the National Library of France, the perfect sphere of the Cenotaph, designed by Louis E. Boullèe in honor of Isaac Newton in about 1780, and the Temple of the Earth of Jean-Jacques Lequeu are cited by historians and critics of architecture as the utopian dream of bending the stone and the force of gravity towards the pure form of a complete sphere. The historical formal equivalence between the architectural dome vault and the sky, assume in our case a deeper meaning. From the words of Boullèe, it is crystal clear the intention of celebrating the greatness of Newton, subtracting his burial from the darkness by placing it in the largest ever builted sky, a majestic stone dome, reversing the natural order of day and night by creating with daylight, in the interior space, the image of the constellations seen in the starry skies. First in the history of planetary science, Lequeu and Boullèe???s stone architecture carried out the plan by drilling the outer surface of the dome to let the sunlight in, directly piercing the darkness and simulating in the inside space the intense stellar glow. The geometric study conducted on the holes in both architectures, made along the stone surface of the spheres, reveals a studied convergence of solar rays, in the Cenotaph, towards the eye of the privileged observer, the one able to stand on the slender platform above Newton???s tomb, thereby creating the sensation of a Ganzfeld , which sets Newton???s Cenotaph in the field of art installations rather than scientific ones. The Lequeu???s Temple instead is designed with a perfect convergence of those rays towards the centre of the sphere, as the most part of modern planetarian, but it is also more visual than scientific in character. 3D virtual models, and simple conical projections, have allowed us to draw the star maps referred to Boullèe and Lequeu???s architectures which, however, show deep differences compared with the contemporary ones. Using the free software Stellarium we have created a good simulation of the visible sky, at the latitude of Paris, in January 4 (Isaac Newton???s birthday), exactly in the year of the Cenotaph project and we can affirm that a good coincidence, between that image and the internal perspective of the virtual model recreated from the point of view, do really exist.