Solid angle at an average angular diameter of 0.5334 degrees or 9.310 radians. The Moon is seen from Earth at an average angular diameter of 9.22 radians. We can substitute these into the equation given above for the solid angle subtended by a cone with apex angle : The resulting value for the Sun is 6.807 steradians. The resulting value for the Moon is 6.67 steradians. In terms of the total celestial sphere, the Sun and the Moon subtend "fractional areas" of 0.000542% (Sun) and 0.000531% (Moon). On average, the Sun is larger in the sky than the Moon even though it
Six degrees of separation We should select any person from the 1.5 billion inhabitants of the Earth – anyone, anywhere at all. He bet us that, using no more than "five" individuals, one of whom is a personal acquaintance, he could contact the selected individual using nothing except the network of personal acquaintances. This idea both directly and indirectly influenced a great deal of early thought on social networks. Karinthy has been regarded as the originator of the notion of six degrees of separation. A related theory deals with the quality of connections, rather than their existence. The theory of three degrees of influence