重力による時間の遅れ
↑ Einstein, A. (February 2004). Relativity : the Special and General Theory by Albert Einstein. Project Gutenberg. https://www.gutenberg.org/ebooks/5001
↑ Uggerhøj, U I; Mikkelsen, R E; Faye, J (2016). “The young centre of the Earth”. European Journal of Physics 37 (3): 035602. arXiv:1604.05507. Bibcode: 2016EJPh...37c5602U. doi:10.1088/0143-0807/37/3/035602.
↑ A. Einstein, "Über das Relativitätsprinzip und die aus demselben gezogenen Folgerungen", Jahrbuch der Radioaktivität und Elektronik 4, 411–462 (1907); English translation, in "On the relativity principle and the conclusions drawn from it", in "The Collected Papers", v.2, 433–484 (1989); also in H M Schwartz, "Einstein's comprehensive 1907 essay on relativity, part I", American Journal of Physics vol.