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Is there an English word that describes a point in both space and time?

If we consider only space, it would be "position" or "location" and if we consider only time it would be "moment" or "instant", but what about the two combined?

I think there may exist a term in physics, for example in relativity theory but I couldn't find any.

To give a bit of context of how I would use it, I'm developing an algorithm where one of the data structures contains a position in space and a moment in time and I need to find a name for it.

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    English is impoverished in time words. There are very few words that only designate time: during, duration, durable, when, then, and try hard to think of more. Normally we use metaphors for time: Money, as in spend time; or Path metaphors like point, line, before, after, coming, long-gone, etc. These are metaphors, centuries old, and they haven't dealt with Relativity yet. Jun 3 at 13:56
  • There isn't a single word for it in English to my knowledge but the phrase "time and place" is used in everyday speech almost as a set phrase. For instance "Can we set the time and place of our next meeting?"
    – BoldBen
    Jun 3 at 15:32
  • Doesn't Relativity ( the dependence of various physical phenomena on relative motion of the observer and the observed objects, especially regarding the nature and behavior of light, space, time, and gravity.) cover that? Jun 3 at 17:56
  • I’m voting to close this question because questions on naming variables, functions, apps, or other computing things are off topic. If you have a sentence you want to use it in, provide a specific context.
    – Stuart F
    Jun 5 at 17:08

4 Answers 4

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There isn’t really any term that you haven’t already considered. Here is a passage from “A Traveler's Guide To Spacetime”:

A spacetime diagram is a useful tool for displaying the spacetime coordinates of events and the motion of objects. In a typical spacetime diagram, one plots an event as a point on a graph. (pg. 40)

Later, that book provides a table describing the analogy between “plane geometry” and “spacetime geometry”. Where the former has “points”, the latter is described as having “events”. (pg. 58)

So physicists use the terms that you’re already considering; there aren’t any additional ones that would work well for your intended meaning.

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If your position in space includes all three dimensions, I think the physics term "spacetime" will suffice.

In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why different observers perceive differently where and when events occur. [1]

Albert Einstein introduced this wholly new topic, “Space-Time,” in 1926 [2].

For a single word that would mean "a point in spacetime," you might consider just using "event."

In physics, and in particular relativity, an event is the instantaneous physical situation or occurrence associated with a point in spacetime (that is, a specific place and time). For example, a glass breaking on the floor is an event; it occurs at a unique place and a unique time. [3]

Philosophy also uses "event" terminology. Events can be objects in time or instantiations of properties in objects.

On some views, only changes in the form of acquiring or losing a property can constitute events, like the lawn's becoming dry. According to others, there are also events that involve nothing but the retaining of a property, e.g. the lawn's staying wet. [4]

You might also find the Stanford Encyclopedia of Philosophy's "Inertial Frames" page useful.

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    Thank you for your answer. "spacetime" is more of a model. To be more precise I'm looking for a single word that would mean "a point in spacetime". Jun 3 at 10:20
  • @ElieGénard If you want to summarize further than "a spacetime point" (einstein-online.info/en/explandict/spacetime) consider just using "event." I just added it to my answer.
    – Nathan
    Jun 3 at 10:26
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    An event implies that something happened. What if one is simply describing a point along a path or trajectory where the only thing that happened is that the spacecraft was at that point at that time?
    – Jim
    Jun 3 at 13:32
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    @Jim I'm not a physicist, but my understanding is that in the context of general relativity the term "event" does not always imply "something happened" (in the 'usual' sense). It can be an "instantaneous physical situation OR occurrence." Regardless, I think your example actually does count as an event. Although contested, in Philosophy, instantiations of an object count as an event simply by retaining a/its property(ies).
    – Nathan
    Jun 3 at 16:24
  • @Jim: That's still something that happened! It may not be terribly notable by anyone's standard, but saying "a spacecraft passes a point 42.529% of the way between Alpha Centauri and Sirius" still defines a particular place and time. Jun 3 at 19:11
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Let's call it a snapshot. I am a special education advocate. I use psychoeducational evaluations of a child to present a snapshot of a child -- a description of the child's strengths, interests, and challenges, at a particular point in time.

Also, we can think about a movie, which is a sequence of still photographs. In essence, that is a time sequence. So an individual still photograph corresponds to a particular time, relative to some other point in time -- a snapshot.

In both of these examples, time is not the only variable. In the first example, we are capturing the child's cognitive ability, level of achievement, and behavior quirks (if any). In the second example, there's plot, character development, lighting, costuming, audio, etc., etc.

Thus, in both examples, there is a rich collection of variable values that can be observed and described, associated with a time value in the sequence.

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In literature and the performing arts, "setting" fits the bill for signifying place and time. I doubt it will ever be used in physics, though.

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