A perturbation in a body’s orbital movement that is cumulative, building up at a rate proportional to the square of the time. Such an effect exists in the orbit of the Moon about the Earth, causing the Moon to recede slowly from the Earth.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。