Natalie Wolchover at Quanta has an article about a campaign by string theorists to argue that we have to accept string theory as our theory of fundamental physics even though there is no evidence for it because it is “un...

There’s a new paper out on the Formalization of QFT, purporting to formalize a QFT using Lean/Mathlib. I’ve been trying to avoid spending time on the hot topics of AI and theorem proving, but in this case there’s a lot of overlap with what I have been thinking about recently (and writte...

The last few postings here have been about rather technical problems with the conventional understanding of how spacetime symmetries and Wick rotation work in the Standard Model. These were written partly because I think these problems deserve to be better known, partly because they motivate a different way of thinking about spacetime symmetries which doesn’t have these probl...

In the last posting I explained how a fundamental problem shows up if you try to Wick rotate a Weyl spinor. Wick rotation is supposed to be analytic continuation in a four dimensional complex spacetime which, in terms of spinors, is $S_L\otimes S_R$ (or equivalently, linear maps from $S_R^*$ to $S_L$). This is acted on by the complex spin group $$Spin(4,\mathbf C)=SL(2,\mathb...

In this post I’ll discuss Weyl spinor fields and explain why Wick-rotating a single Weyl spinor field appears to be impossible. This motivates a proposal for a different way of thinking about the relation between spinors and vectors, described by the slogan “spacetime is right-handed”.

Written in energy-momentum space, the equation of motion of a right-handed Weyl spin...