Is Space-time Really Doomed?

For many years now it has become conventional for theorists to argue that "space-time is doomed", with the difficulties in finding a quantum theory of gravity implying the necessity of basing a fundamental theory on something quite different than usual notions of space-time geometry. But what is this space-time geometry that is doomed? In this essay we'll explore how our understanding of four-dimensional geometry has evolved since Einstein, leading to new ideas about such geometry which may not be doomed at all.Comment: Essay written for the Gravity Research Foundation 2022 Awards for Essays on Gravitatio

Spacetime is Right-handed

We describe the relation between vectors and spinors in complex spacetime in an unconventional chirally asymmetric manner, using purely right-handed spinors, with Minkowski spacetime getting Wick rotated to a four-dimensional Euclidean spacetime with a distinguished direction. In this right-handed spinor geometry self-dual two-forms can be used to get chiral formulations of the Yang-Mills and general relativity actions. Euclidean spacetime left-handed spinors then transform under an internal $SU(2)$ symmetry, rather than the usual $SU(2)_L$ spacetime symmetry related by analytic continuation to the Lorentz group $SL(2,\mathbf C)$.Comment: Typos fixe

Not even wrong: the failure of string theory and the search for unity in physical law

Has physics gone off in the wrong direction? Peter Woit presents the other side of the growing debate on string theory--arguing that it's not even scienc