Did the day I was born occur already, or is it occurring relatively to me in the past?

Will the day I die occur or is it occurring relatively to me in the future?

I know that some physicists are playing around with the idea of time flow vs non time flow, and I wanted to get any kind of references or ideas from a philosophical aspect.

*Using the word relatively has nothing to do with the theorems of general and special relativity.

  • 2
    You may want to look into McTaggart on the A-theory and the B-theory of time at plato.stanford.edu/entries/time which basically concerns the question of whether there is an objective present moment (the A theory) or if terms like "present, past, and future" are purely relational (the B theory), like spatial terms such as "here" or "to the north" and "to the south". Related to this is presentism vs. eternalism, where a presentist believes only present things exist and an eternalist believes past things and future things are equally real.
    – Hypnosifl
    Feb 5, 2021 at 4:21
  • Another good intro is at rep.routledge.com/articles/thematic/time-metaphysics-of/v-2 -- see the box labeled "Contents" at the left for the different sections of the article
    – Hypnosifl
    Feb 5, 2021 at 4:46
  • @Hypnosifi Both are great!! Feb 5, 2021 at 5:42

2 Answers 2


My limited opinion on this matter, picking a line from Hypnosil's linked page, Time & Physics :

"it follows from the relativity of simultaneity that there is no fact of the matter as to what is present"

Just because everything is relativised to frames, doesn't mean the present moment is not universal. It just means it would be inaccessible.

And it seems to me more likely that the present moment is universal, (although I am open to contradictory information, with great interest).

Edit 21/02/2021

Moved to a separate answer to allow more easily for comments.

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    "It has often been commented by physicists that Einstein’s GTR {thus} reintroduced the relations of absolute simultaneity that his STR had denied. (Craig, Smith 2007: 8); same in Jammer M., 2006. Concepts of simultaneity. p285.
    – sand1
    Feb 5, 2021 at 13:13
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    @sand1 - Different coordinate systems with different defs of simultaneity are equally valid in general relativity just as in special relativity--p. 285 of Jammer's Concepts of Simultaneity says that GR does not have objective simultaneity, approvingly quoting Moller's comment that "in a general system of reference it is impossible to define globally standard simultaneity between any two events" (p. 284 mentions Moller as one who 'proved that there are space-time reference systems in general relativity that do not admit a global standard simultaneity')
    – Hypnosifl
    Feb 5, 2021 at 16:47
  • ...as for p. 8 of the Craig/Smith reference, that's referring to the simultaneity convention commonly used in the FLRW cosmological model, but although that convention is the most "natural" one in that model since it ensures each surface of simultaneity has a perfectly homogenous distribution of matter, you could use a different convention and the laws of physics would be the same, it's not a 'preferred' frame in a physicist's sense. And of course the real universe has inhomogeneities no matter what convention you use.
    – Hypnosifl
    Feb 5, 2021 at 16:56
  • Finally note that William Lane Craig, the co-author of the section with the comment about reintroducing relations of absolute simultaneity, is an evangelical christian philosopher who seems to believe in absolute time for religious reasons (see his lecture here), so I wouldn't take him as a reliable guide to what physicists think about absolute simultaneity (he doesn't cite any specific physicists for the claim that the simultaneity convention in simplified cosmological models supports absolute simultaneity)
    – Hypnosifl
    Feb 5, 2021 at 17:00
  • 1
    In general relativity, we can rule out the idea that the equations for the laws of physics will take a special preferred form if you assume a coordinate system with a special definition of simultaneity (which would be true in certain 19th century 'luminiferous aether' theories for example). It's conceivable a future theory of quantum gravity replacing GR would work like that though (but few physicists think that's likely), and even if there is no definition that's preferred according to physical measurements you are free to assume an unmeasurable metaphysical truth about simultaneity.
    – Hypnosifl
    Feb 7, 2021 at 18:08

Did the past occur or is it occurring relatively ... ?

"it follows from the relativity of simultaneity that there is no fact of the matter as to what is present"

Does simultaneity relate to presentism? For sure at different locations what is observed to be simultaneous differs, but that does not affect the present moment. The present moment does not have to be defined as having the same observed events happening simultaneously. And what could anything other than the present moment even be? Different present moments together? That doesn't make sense.

Regions of spacetime may be unobservable, but that does not mean they drift apart temporally into variations of the present. That would be a completely unnecessary and absurd complication.

So the answer to the above question is: the past occurs both absolutely and relatively to a varying degree depending on one's speed of movement through space. There are no places where one person's past is in another's future. They are all in the past of the present moment.

This has no bearing on the block model, which shows a real trajectory through time. Only one time slice is the present moment. Presentism may deny the reality of the past in a manner of speaking, but that does not stop that singular time slice in the block model being the present moment. Presentism and eternalise are not at odds in this respect.

the Moving Spotlight Theory is an example of an eternalist A-theory that subscribes to the dynamic thesis. ... Spotlighters think instead that there is a spacetime manifold, but one particular region of the manifold is objectively distinguished — the present.

Stanford Encyclopedia of Philosophy The Moving Spotlight Theory

Fragmentalists (see Fine 2005) think that there is a spacetime manifold but that every point in the manifold has its own type of objective presentness, which defines a past and future relative to the point.

Fine's dismissal of the present appears to rest on special relativity's view on simultaneity, but as discussed, just because different observers do not agree on what is observed as simultaneous does not mean they are not in the same present.

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