The earth, the abode of the only form of intelligent life in the universe of which we are aware, is a minor member of a system of nine planets, 40 or so moons and about 100 billion asteroids orbiting around the Sun, an average-size member of the 100-billion-star community making up our galaxy, the Milky Way. It is the third planet to the Sun, which it orbits, following an almost circular elliptical path maintaining an average distance of 1.5×108 km, with (...) the longest and the shortest radii now being 1.53×108 km and 1.47×10 km respectively (Fig. 1). This orbit is subject to changes in its “eccentricity” (i.e., in how much it deviates from a circle) with periods of 105 and 4×10 years5 years (Fig. 2A). In addition, the elliptical orbit itself slowly rotates as shown in Fig. 2B, in what we call the precession. (shrink)

The universe, of which our domicile the planet Earth forms but a minuscule part, has an architecture that changes and has been changing in time. In other words, it has a history of evolution. Lack of experimental evidence denies us the knowledge of what the universe was like “at the time of its origin,” as discussed by Hubert Reeves in the preceding chapter. Neither do we know much about its geometry, simply because our observatories are concentrated, for all practical purposes, (...) vanishingly close to a single point in an immensity whose size can only be measured by the billions of years required by light to go from one extremity to another! (shrink)