In 1949, Kurt Gödel showed that there exist solutions to Einstein’s equations of general relativity allowing for closed timelike curves. A closed timelike curve is a world line (in space and time) along which a material particle can travel returning to its spacetime starting point. The existence of such curves would allow time travel into one’s own past leading to all kind of causality paradoxes.
Einstein, commenting on what now is known as the Gödel Universe, remarked about the possible existence of causality violating curves that “This problem had already bothered me when constructing the theory without being able to come to clear conclusions”.
Still today, there is an ongoing debate on how physical such solutions are and whether general relativity would prevent the formation of regions where causality violation is possible, e.g. S.Hawking’s proposal of a “chronology protections conjecture”. Some physicists speculate that closed time curves might be ruled out by a future theory of quantum gravity which would replace general relativity and there are many other attempts to overcome that problem. Closely related are Gödel’s philosophical ideas on the existence of time, a subject that he intensively discussed with Einstein in Princetown. “In my view Kurt Gödel’s papers represent an important contribution to general relativity, especially his analysis of the concept time.” said Einstein.
The Kurt Gödel Society intends to celebrate the 70th anniversary of Gödel’s seminal publication and the 100th anniversary of the decisive experimental verification of general relativity by organizing a conference at the University of Vienna, Austria. This event should bring together the prominent researchers from the fields of Physics, Mathematics, Philosophy and Artificial Intelligence.
The conference will be enhanced with a special exhibition about life and work of Kurt Gödel with emphasis on the Gödel's solution.
Further information can be found here.