Editing Chronology protection conjecture (section)

{{Short description|Conjecture that the laws of physics prevent closed timelike curves}}
The '''chronology protection conjecture''' is a hypothesis first proposed by [[Stephen Hawking]] that [[laws of physics]] beyond those of standard [[general relativity]] prevent [[time travel]]—even when the latter theory states that it should be possible (such as in scenarios where [[faster than light]] travel is allowed).  The permissibility of time travel is represented mathematically by the existence of [[closed timelike curve]]s in some solutions to the field equations of [[general relativity]]. The chronology protection conjecture should be distinguished from [[cosmic censorship hypothesis|chronological censorship]] under which every closed timelike curve passes through an [[event horizon]], which might prevent an observer from detecting the '''causal violation'''<ref>{{cite journal|title=Are Causality Violations Undesirable? |date=2008-10-29 |doi=10.1007/s10701-008-9254-9 | volume=38 |issue=11 |journal=Foundations of Physics |pages=1065–1069|arxiv = gr-qc/0609054 |bibcode = 2008FoPh...38.1065M |last1=Monroe |first1=Hunter |s2cid=119707350 }}</ref> (also known as '''chronology violation''').<ref>{{cite journal | author=Visser, Matt| title= Traversable wormholes: the Roman ring | arxiv=gr-qc/9702043 | doi=10.1103/PhysRevD.55.5212 | volume=55 | issue= 8 | journal=Physical Review D | pages=5212–5214| bibcode=1997PhRvD..55.5212V| year= 1997 | s2cid= 2869291 }}</ref>