ocr: CLOSED UNIVERSE A model of the universe which is no lon- ger generally tavoured by current thought. In a closed universe, the uni- verse will one day start refracting instead Inac closed universe, gravitation's retracting of expanding forever, ending in an event force will one day conquer the expanding called the big crunch. The opposite is the motion energy. The situation can be com- open universe, with a third model pared to that of escape velocily. If one described as balancing between the two. throws a rock up from the Earth's surtace, When the closed universe one day ends, the rock will r ...
