《晋书·志·第一章》
天结而高在上面，有常外安定之形；地固而实在下面，有静止不变之体。
天确乎在上，有常安之形；地塊焉在下，有居静之体。
Heaven is hollow and high above, existing in a consistently stable form; the earth is solid and firm below, existing as a stationary and unchanging substance.