Dear Colleagues, Minkowski Institute invites colleagues, working in areas related to the foundations and nature of spacetime, to participate in a meeting, which will address and deal with a disturbingly unprecedented (on two counts) situation in fundamental physics: It appears that the reality of spacetime is an experimental fact (as Minkowski de facto demonstrated), i.e., it appears experimentally confirmed that the concept of spacetime represents a real four-dimensional world with time as the fourth dimension. What makes this experimental support for the reality of spacetime unprecedented is that the experiments, which confirmed the kinematic relativistic effects, would be impossible if the world were not four-dimensional. To understand why this is so, it is sufficient only to see in Minkowski’s paper “Space and Time” that length contraction is impossible in a three-dimensional world. What also constitutes an unprecedented situation in fundamental physics is that, so far, most physicists have not addressed even Minkowski’s own arguments for the reality of spacetime; they simply ignored them arguing (at best) that the concept of spacetime is “just a description” and that “the question of the reality of spacetime belongs to philosophy”?! (both “justifications” for ignoring the question of the reality of spacetime are incorrect). However, as we all (in theory) know, physics, particularly fundamental physics, does not work in that way (by avoiding fundamental issues) and cannot advance by ignoring arguments, especially given that those arguments are firmly based on the experimental evidence to such an extent that experiments would be impossible if those arguments were wrong. Addressing Minkowski’s arguments for the reality of spacetime is of crucial importance for physicists because the physics of a three-dimensional world is fundamentally different from the physics of a four-dimensional world: - In a three-dimensional world physics deals with motions and interactions of three-dimensional particles / bodies. - In a four-dimensional world physics deals with interrelations between worldlines (or worldtubes in the case of extended bodies), as Minkowski explained, and “static” deformations of curved (non-geodesic) worldtubes because there is no dynamics in spacetime; it is incorrect even to say that a particle follows a timelike geodesic worldline because in spacetime the particle itself is a timelike geodesic worldline. The proposed meeting can become one of the biennial Minkowski meetings on the foundations of spacetime physics (https://www.minkowskiinstitute.com/meetings/). We are willing to co-organize such a meeting with other institutions. If interested and have any suggestions, please reply to this message or to mi@minkowskiinstitute.com. Best wishes, Vesselin Petkov One of the founders and current director of Minkowski Institute Montreal, Canada https://minkowskiinstitute.com <https://minkowskiinstitute.com/> vpetkov@minkowskiinstitute.com <mailto:vpetkov@minkowskiinstitute.com> Personal page: http://vesselinpetkov.com <http://vesselinpetkov.com/>