碎石堆(英语:Rubble pile)—由許多石塊組成,受重力拉引聚集的天體 重力物理與相對論時間軸(英语:Timelineofgravitationalphysicsandrelativity)—時間軸 Science with the VLTI. European Southern Observatory
[2009-01-29]. (原始内容存档于2013-11-12). Molecular Expressions: Science, Optics and You – Timeline – James Bradley. Florida State University. [2009-01-29]. (原始内容存档于2013-06-30)