Causal cone

{{#ev:youtube|https://www.youtube.com/watch?v=1YFrISfN7jo%7C%7C%7C%7C%7C}}

Causal Cone/Loop and John von Neumann Algebra

{{#ev:youtube|https://www.youtube.com/watch?v=k3AtJ7wQKsk%7C%7C%7C%7C%7Cstart=3048}}

Why just a Circle

At the end of the same video, Vaughan Jones said the following:

The space-time dimensions go all the way down to one.

{{#ev:youtube|https://www.youtube.com/watch?v=k3AtJ7wQKsk%7C%7C%7C%7C%7Cstart=3877}}