The Large Hadron Collider (LHC) at CERN was built to create conditions of the Big Bang and find the Higgs boson (see also CERN).
Holger Bech Nielsen, of the Niels Bohr Institute in Copenhagen, and Masao Ninomiya of the Yukawa Institute for Theoretical Physics in Kyoto have suggested that the Higgs boson eventually created by LHC in the future may have travelled back in time to sabotage its creation in the first place.
Paradox galore. Awesome!
Also see my previous post on the topic.