🌐EnglishEnglishEspañolFrançaisItalianoNederlandsPolskiPortuguêsTürkçeРусскийไทย한국어中文日本語EntityQ1876815· pop 19· linked from 91 articlesclosed timelike curveworldline (timelike curve) in a Lorentzian manifold that is closed (returns to its starting point)Connectionstemporal paradoxEntitycausal structureEntityCategoriesLorentzian manifoldsTime travel