Okay, so humans are finally transitioning to a space-colonial society. We sent ships out, colonize worlds, etc... We aren't really in the business of sending multigenerational ships. Instead we use time dilation. We generally only go somewhere when we can get there within a year of subjective time (although probes can take longer.) The only potential problem would be that then the ships would far outlive the people on the planets, and all you get is a bunch of ships shooting everywhere, with no real centralized civilization or cultural. I call it potential, because it has long been solved: time dilate the people back home as well. Most bases our put into orbit around gravitationally strong bodies. Shooting a small black hole into a gas giant usually does the trick, although even some suns have been used this way if the inhabitants are rich enough to entirely forgo solar power.

Now we have a problem: keeping time. Note that it isn't so much a technical problem: computer get along just fine calculating each other's velocity. The problem is people adapting to the fact that time is different everywhere you go.

For an example of the confusion. Let's say you are going to visit gravity park in New New New York solar system. Your tell your friends you will be gone for about a week. Is that a week of the parks time, your friends time, or your own time?

For another even more complex example, consider that your space car breaks down, so you get it towed to the space mechanic. The space mechanic says it will take about 10 days to fix. 10 days for whom again? (Both you and space garage, and space mechanic can undergo different, and varying amounts of time dilation between now and then.)

How would how we describe time have to change in response to this?

  • Most reference frames humans travel in are within 30x of each other, depending on wealth and occupation.
    • An individual typically will only experience a 5x difference between fastest and slowest for their weekly commutes, and maybe up to 10x difference if they move (but stay in the same socioeconomic group and occupation.)
    • That is to say, an observer at infinity would observe a rich person's clock typically tick 30x slower than a poor persons. A person clock tick between 1/10th to 10 times the rate after they move to a new home, a person clock tick 5x faster at the fastest part of their weekly commute to the slowest.
  • Generally, ships and bases don't follow any regular rules. A computer can compute it no problem, but if you are taking a space bus that makes regular use of black hole gravity slingshots, time dilation throughout the journey can change in a way that is hard for humans to keep track of.
  • Changes to language shouldn't to inconvenience people in their daily lives. It shouldn't be complicated to say "here, watch this 3 minute video," or "give me a minute to figure out the answer" if you are face to face with someone.

An answer should address both changes to language (both time unit words like "second" and "week", and also somewhat relative words like "then", "now", "before", "after", etc...) and the technology to make it easier to deal with (what the heck would should your wrist watch tell you?)

Note: Don't forget to take relativity of simultaneity in to account. That just messes with things more.

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    $\begingroup$ I'm confused. Wasn't the whole point of time dilating everyone to make it so time would be perceived the same wherever you went? Also, are the time frames are constant for a given planet/universe or are people carrying around personal devices to shape their own space-time continuums? $\endgroup$
    – Josh
    Jul 25, 2015 at 18:35
  • $\begingroup$ Wow... This question has got me all confused about time dilation. I thought it was about observing something that it moving really fast away from you. Im gonna go relearn what time dilation is now, before I forget. $\endgroup$
    – Necessity
    Jul 25, 2015 at 18:55
  • $\begingroup$ @Josh Humanity has been time dilated billion of times. Its amazing how synchronized it is at this point. Also, time dialation only occurs through relativity, not magic. $\endgroup$ Jul 25, 2015 at 19:32
  • $\begingroup$ That's what I thought, but doesn't that make the question irrelevant? Your car will be fixed in ten days as you perceive time, whether that actually equates to an eon or a microsecond. Am I missing something? $\endgroup$
    – Josh
    Jul 25, 2015 at 19:35
  • $\begingroup$ @AdamNicholls Study the resolution of the twin paradox. $\endgroup$ Jul 25, 2015 at 19:35

2 Answers 2


I don't think that new words will arise to deal with time discrepancies; merely that their meanings will shift slightly to accommodate the change in context. By the time you speak of, when this has been reality for a long time, we should have settled on one of two systems to handle everything efficiently:

  1. All time is local. When I say how long something will take, I am referring to the Relative Time Zone (RTZ) I am in at this moment. If you won't be spending all of that time moving at the same speed as I am right now, it is up to you to figure out how much time that actually means for you (which will be easy to do, as explained below). A consequence of this would be that You truly can't care about "real" time. Culture at this point has embraced relativity to the degree that trying to describe time by a universal frame of reference is seen as irrelevant. While there may be one or two fields of science or business where a constant frame of reference is discussed (such as the those engineering newly colonized systems to keep them roughly in sync), they would probably use an arbitrary speed as a reference, rather than the same words used for local time. (For example, either the speed time originally moved on Earth, or perhaps the average speed time moves across the universe, is declared as the constant q. Solar system A's RTZ is 9q, solar system B's is 13.6q, and a bus traveling between them is currently moving at 12q and accelerating by .2q/hr.)

  2. All time is universal. This means that an arbitrary coefficient of q has been declared the "official" time. I tell you how long something will take in Standard Time, and you know that as you travel through RTZ's that are faster or slower, the time to completion becomes sooner or farther away. An advantage to this is that I get to keep my RTZ private, since it isn't relevant to any conversion, and your question indicates that faster speeds may be a status symbol. A consequence is that people will rely on figures of speech rather than actual units of time for making quick estimates. Humans in our time have a decent sense of time because it is constant, so we say something will take about five minutes or half an hour. If the speed time moves at changes frequently in our day-to-day lives, we will lose that ability (in a universal time system, that is; we can still judge relative time, as in the first example). Instead, we will likely give time estimates by referencing common activities with fairly constant relative times, such as "I'm almost ready, just give me ten breaths," or "I'll be stuck at the office for at least another three-course meal." Eventually, we may come up with a standard list of radioactive elements to make this easier, so we can refer to relative time by their half-lives. (For example: "I'll be there in three Plutoniums.)

Whichever system triumphs, calculating differences will be incredibly simple: there's an app for that. Virtually everyone in modern society carries a device with them that can make advanced calculations; in the future this will be even more true. You said in your question that computers can handle these calculations easily. Whether it's a watch, a smart phone, or nanobots in your eyes giving you a constant HUD, you will have something close at hand that will instantly convert standard time or someone else's local time into something meaningful to you. However, tracking time in multiple locations will become much more common. Businesses that work with people in multiple time zones today typically have clocks that track the time in each location. In a time where relativity comes into play on your daily commute, everyone will care "what time it is" somewhere else. A typical watch will probably give the time for your home, office and current location. Many people will prefer to have the coefficient of q for each RTZ displayed right below the time. The contacts in your phone would have local time displayed next to each name. (Assuming we solve the problem of communicating over such distances, converting sound waves to the right speed would be easy. However, solving that problem would require transmitting data FTL, which isn't harmonious with the effort you have taken to keep your world operating under known laws of physics.)

The meanings of relative words such as "before" or "after" will not change, though the contexts in which they can be used may decrease. Relative words are meaningful in relation to the words they are used with. While "before an hour has passed" would no longer make sense if Standard Time is adopted, nothing about time dilation will change the meaning of "after I get back from the store." We will simply choose our language to express concepts we easily understand rather than create new words to elaborate on concepts that already confuse us.

One consequence of this reality you didn't specifically ask about is that time-intensive processes will exploit relativity to be completed "sooner". Put dinner in a slow cooker and then take a quick trip around a black hole. You age thirty seconds while your meal cooks for six ours. Similarly, agriculture and any aging process will be done primarily in those places where time passes the slowest, making them more plentiful for the rich living at faster speeds.

Edit: the relativity of simultaneity is only relevant if a physics-breaking form of instant communication exists. Suppose you and I are on two very distant planets and I send you a message such as "Don't come over until after my wife leaves." Both my message and any way you have of observing my wife leave will travel toward you no father than c. So if my wife leaves after I send the message in my frame of reference, she will leave after I send the message in every frame of reference. This is true even if we are on two ships traveling toward each other at >.5c each (and therefore >c relative to each other). There's only a problem if You get my message instantly and then look through your telescope and see that I haven't been born yet. If this type of communication is possible in this world (as it isn't in ours), then we'll quickly get used to the problem and rely heavily on instant communication to avoid it.

While cheating husbands are safe, we would have to deal with judging who came first in, for example, a contest submission, but this wouldn't be hard. Either we order submissions by the order received, or we create a standardized intergalactic postmark. Both methods are used in smaller scale today for various purposes and work just fine.

  • $\begingroup$ Very good answer. One thing to be addressed is the relativity of simultaneity. That is what I meant by before or after. If someone is sufficiently far away, "before" and "after" would probably have to change. This would also pose problems for keeping track of time in other places somewhat. $\endgroup$ Jul 25, 2015 at 21:49
  • $\begingroup$ I think our apps would take care of that. There are only three possible relevant frames of reference between points A and B: A's local time, B's, and (possibly) an arbitrary standard. Either we pick a standard usage for simplicity (more likely) or the app displays the time from each reference point. $\endgroup$
    – Josh
    Jul 25, 2015 at 21:56
  • $\begingroup$ The problem is "time over there" is sort of an ambiguous question to ask. Asking if my app's clock ticks and B's clock ticks are happening at the same time is somewhat illdefined. I am thinking "synchronized relative arbitrary standard frame" may be the best, but then the arbitrary frame wouldn't have any other purpose. $\endgroup$ Jul 25, 2015 at 22:01
  • $\begingroup$ @PyRulez, see my edit. In a nutshell, the realities of living spread out across such distances will prevent this from being a problem. $\endgroup$
    – Josh
    Jul 26, 2015 at 21:29
  • $\begingroup$ Yeah, I guess relativity of simultaneity only becomes a problem when things are far away, when it isn't a problem. And I would think that a contest would be by order received. Or it could be that if two entries are the same time in some reference frame, they are considered the same time for purposes of the contest, since they couldn't influence each other. $\endgroup$ Jul 26, 2015 at 21:33

The same way we actually already do. A jet fighter pilot who spends a considerable amount of time moving 'very fast' does actually move through time at a different rate than a man who spends most of his life sitting in a chair on his front porch. Since the difference is so minute we don't perceive it but it is true.

  • $\begingroup$ Not a bad starting point but the original question wanted specific aspects of the problem answered - which you didn't do. Please use this as your starting paragraph and expand on your answer. $\endgroup$
    – Jim2B
    Sep 30, 2015 at 14:40
  • $\begingroup$ The time dialation of a fighter pilot is negligible. $\endgroup$ Sep 30, 2015 at 15:47

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