"Calculate as if there was no causality ... but " implies what I wrote to Steven Dufourny:
"Steve, Instead of writing t=0 I should perhaps be more careful and write
t_past=t_future=0.
You (and perhaps many others) did not understand that t_past can be imagined counting for a snapshot the distance backward (leftward) from actual zero toward older events. For the same snapshot, t_future counts forward (to the right as does usual time). The reference zero is the same for past and future. You could call it the point now: Actually, the notion now in the sense of something perceivable is as fuzzy as also are today and within this millennium. Of course, the natural reference is permanently shifting relatively to the ordinary time scale: Age is growing. So far, this perspective is utterly uncommon in physics. All religions were forced to choose different points of reference for the same time scale."
A majority of physicists will, in principle, agree with his reply:
"Hi Eckard , I respect your analyse but I don t understand why you make this link past and future, they are just parameters of time, the past is the past and the future is not still there , and the present is just a Clock of evolution, a pure duration, is it important to analyse this time, we cannot check it for me , we can just utilise the relativity like a tool, like we see our past more we go far in space due to this special relativity, like we see our sun 8min 20 sec in late and we can decrease our internal Clock , so we can go in the future more quicly but we cannot retrun at our present and reality, so is it relevant ? it is odd for me to analyse this time, there is nothing of odd with this time, it is just a paramter of evolution irreversible entropically speaking for me. Could you elaborate please why you consider this past and future =0 , what is the philosophy really beyond, what we must understand about this and why you insit Always with Fourier ? please elaborate, light me, regards"
Because presentism is unable to specify the duration of a "the present", it deliberately blurs the alternative between past and future. As there is nothing between positive and negative numbers there is no extended state but merely a border point, something that has no parts, between past and future.
While, people tend to agree on that "past and future are just parameters of time", I would like to be more careful and clearly distinguish objectively measurable reality from any abstractions that stripped off the link to reality, for instance records and models. The usual notion of time is thought to extend from minus infinity to plus infinity. Hence it belongs to the latter: Future data cannot be measured in advance. Philosophy has it: In reality the past is unchangeable, the future is open.
We will perhaps agree on that it was and is reasonable to conceive annual cycles (in Christian religion) or moon periods (in others) as a fundamental temporal pattern. While they quasi provided arrows with equidistant marks on it, a natural point of reference (t=0) is missing with this usual notion of time. Numbering the marks requires to either agree on an arbitrarily chosen reference point, or to choose the border between past and future as the unique, natural, and common to past and future reference point. The laws of physics are valid in both cases. Usual time favorably attributes a fix value of time to an event. The distinction between past and future time avoids a lot of intentionally veiled inconsistencies. When Fourier claimed that the complex transformation is exactly as extended as is reality, he introduced an undecided redundant freedom of arbitrary choice that arose from the usual notion of time.