DavidMartin's latest activity
-
DavidMartin replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.That seems close in spirit to what I’m asking about — although in that framework the S relation itself is still taken as primitive. My... -
DavidMartin reacted to robphy's post in the thread Graduate Can a causal or time-like structure emerge without assuming a metric? with
Like.
Along these lines (assuming (3+1)-spacetime): "The causal order C determines the conformal structure of space-time, or nine of the ten... -
DavidMartin reacted to robphy's post in the thread Graduate Can a causal or time-like structure emerge without assuming a metric? with
Like.
This might be of interest: E. H. Kronheimer & R. Penrose (1967) "On the structure of causal spaces" Mathematical Proceedings of the... -
DavidMartin reacted to Sagittarius A-Star's post in the thread Graduate Can a causal or time-like structure emerge without assuming a metric? with
Like.
In classical physics, the only "asymmetric" law, which contains an arrow of time, is the the second law of thermodynamics. -
DavidMartin replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.That’s a good point — in classical dynamics the second law is indeed the only fundamental time-asymmetric principle. My question is... -
DavidMartin replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.My question is slightly more “upstream”: are there approaches where causal order is derived from some underlying relational structure —... -
DavidMartin replied to the thread Introducing myself (by myself).Dear Jedi, Thank you for taking the time to read my paper and for your kind words — it truly means a lot coming from someone with your... -
DavidMartin replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.I’m trying to understand whether causal order itself might arise from more primitive relational asymmetry. -
DavidMartin replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.Thank you robphy, I have so much questions ... Malament’s result is particularly interesting — if I understand correctly, it shows that... -
DavidMartin replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.Thanks, that’s helpful. If I understand correctly, Robb’s “conical order” is essentially an order-theoretic notion of “before” and... -
DavidMartin reacted to Ibix's post in the thread Graduate Can a causal or time-like structure emerge without assuming a metric? with
Like.
I'd have said SR itself fits the bill, at least if you follow Einstein's original postulates rather than starting by postulating... -
DavidMartin replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.I agree that in Einstein’s original formulation, causal structure is not postulated geometrically but follows from the Lorentz... -
DavidMartin posted the thread Graduate Can a causal or time-like structure emerge without assuming a metric? in Special and General Relativity.In most relativistic frameworks, time and causality are defined through an underlying spacetime metric with Lorentzian signature. I’m...