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I'm working on a series and attempting to create a more universal set of units. For this post, I will simply ask this: Is it feasible to redefine the meter to be the distance light travels in 1 second so that the unit is a whole number of: 300,000,000m. (Instead of the current 299,792,458m) . This would make the new meter (let's call it a Standard Meter) 0.9993081933...m. The downside to this is that it relies on the current arbitrary second. But I think, for the sake of sanity, it would be nice to keep that as it is because it does have a scientifically defined time. The second part to this is a product of a new standard year, which is 30,000,000 seconds. Each minute is 100 seconds. Each hour is 100 minutes. Each day is 10 hours (100,000 seconds which is just under 28 "Earth hours"), each month is 30 days and there are 10 equal months. The new standard year would be very similar to a traditional Earth year, only defined off of something that is standardized. Bottom line I am getting to, is this would make a light year 9.0Pm (Petameters) exactly. Does this make sense and is it feasible to construct a world/universe around this for a series of hard sci Fi stories?

Thanks everyone

Edit: Just to clear up a few things. The new Standard System I am proposing will not be linked to any planet, but it will refer to similar times based on Earth times. This will be for human and Earth biological entities. The new standard will use the second as it is based off the current second (dealing with the Cesium atom). I understand that the meter has a scientific definition off the speed of light, I just want to know if it is reasonable to alter that definition to create a whole number that will make general space travel and time keeping easier and more universal. To summarize 1 standard second = 1 Earth Second 1 Std. minute = 100 seconds 1 std. day = 100,000 seconds 1 Std. year = 30,000,000 seconds 1 m = 1/300,000,000 of a second of c. Which would make c=300,000,000 m/s I know I could also redefine the second to be a more rounded number, but I think the second should stay as it is.

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  • $\begingroup$ Does this take place on Earth? Or is it another planet somewhere in the solar system (Or space perhaps?) One issue I see with doing something like this is incorporating other parts of science that rely on the speed of light. You will end up changing a lot of other physical constants to keep this simplicity. For most readers if this takes place on earth keeping 60-60-24 days would make more sense then constructing this 100-100-10 time system. $\endgroup$ – Edeki Okoh Feb 20 '20 at 16:36
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    $\begingroup$ Plausibility (feasibility) is in the mind of the reader, not the author. If you are good at selling the concept, the reader will accept it. If you make the confused reader get out a calculator to figure out what you mean, then they will likely abandon the story before reaching your brilliantly-written conclusion. $\endgroup$ – user535733 Feb 20 '20 at 16:47
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    $\begingroup$ How does messing with units equal something you could "construct a world around?" $\endgroup$ – puppetsock Feb 20 '20 at 17:32
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    $\begingroup$ Why do you even bother with separate units for length and time? One of them is enough, as they are of the same nature. Just measure lengths in seconds, as a truly rational Vulcan would. For example, I am 6.004 nanoseconds tall; the (great circle) distance between Bucharest and New York is 25.491 milliseconds. Or, for a twist, measure durations in meters; for example, the duration of an average solar day is 25,902,068,371 kilometers. $\endgroup$ – AlexP Feb 20 '20 at 18:18
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    $\begingroup$ I am still not seeing any world building here. Voting to close. $\endgroup$ – puppetsock Feb 20 '20 at 21:28
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Is this based on earth, or is this a planet on which these measurements make sense? Because if you redefine one unit of measurement for uniformity, other units might not necessarily fit into that standard.

Your system is based around one measurement (the speed of light), and tries to conform the rest around that. On earth at least, more factors play a role.

One day is from midnight to midnight. We could define that to 10 hours no problem, that would set our baseline for time. A second could be derived from that quite easily with your system. But the trip around the sun takes an amount of time that you cannot fit inside that system. It will never be perfectly 300 days, it might be 300 and a bit, or a bit less. It might even be 365.2425. This is why we have the concept of leap years. You cannot stretch your day to make it fit, as you will have a day/night shift. You cannot stretch your year to make it fit, as you will have seasonal drift. (For example, if we didn't have the concept of leap years, we would be almost a year and a half further in time, and it would be the opposite season on the same date.)

The rest of your measurements could possibly be stretched (like the meter) to fit. But this won't be easy, as every single measuring unit will need to be adjusted.

If this system is not planet bound at all, but just based of a space faring species trying to easily track time, then yes. Everything can be squeezed around the speed of light. It still won't be easy though. (Just look at how long it takes for Americans to adapt to the scientifically superior metric system for starters).

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I don't think it makes much sense to start playing around with physical constants. Since this is a science fiction novel, you may want to bring in other physics concepts later in the story. By changing the speed of light, you are changing a lot of other concepts that rely on this fixed concept to make any sense.

And its important to remember that seconds, minutes, hours are all relative to earth. We are basing it on how many spins of the earth there are before we rotate around our sun once. Using this standard, a day on Jupiter using this standard is just under 10 hours.

One way around the issue is using some universal day not depended on a planet. Lets say how long it takes for some distinct planet to orbit around a black hole. Then you can standardize the seconds-minutes-hours to be 100-100-10.

And using this, you can say that the speed of light is now 300,000,000 based on this new standard. So it would be possible to explain this change.

TLDR: Don't base it on earths spins but the spins on some far away object and then based time off this.

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    $\begingroup$ The OP isn't proposing to change the speed of light, but to redefine the meter so that the speed of light is exactly <nice round number> m/s. (Note that this could also be accomplished by redefining the second.) Besides, everyone knows the speed of light is actually 6.706e+8. $\endgroup$ – Matthew Feb 20 '20 at 16:56
  • $\begingroup$ I understand that. But by redefining one thing you will have a cascading effect of redefining anything built on that which is my point. And physical constants built on c this will have the same issue. If this is a one off thing then it doesn't matter. But I can see how OP can do something like that and forget to account for it later on in the story, giving logical errors. $\endgroup$ – Edeki Okoh Feb 20 '20 at 16:59
  • $\begingroup$ True, but I would argue that inventing an alternate units system is all or nothing. If it's different from Metric, it's probably easiest to keep straight if it shares nothing with Metric. (A unit convertor that lets you create custom units can help here.) Otherwise, just claim that translation convention is in effect and don't bother. $\endgroup$ – Matthew Feb 20 '20 at 17:04
  • $\begingroup$ Which is why in my answer I suggest simply changing what its based on rather than rounding based on known constants (earth's spin). By changing what its based on you can still jump between the two without getting into errors since they are technically the same thing. The issue with what OP is saying is c is 300,000,000m/s, which its not based on what a meter is. But basing c on the spins around some object far out in the universe which is 300,000,000 units/units2 you get around this issue. $\endgroup$ – Edeki Okoh Feb 20 '20 at 17:26
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The problem with your assumption is that "a second is arbitrary." Which it isn't and hasn't since the 1940s with the introduction of the Quartz Crystal Ocillator clocks, which kept a second better than the Earth's rotation (which is not uniform, but is corrected with "leap seconds" to the new standard). It was redefined in 1967 to be "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom" (at a temperature of 0 K)" which is so accurate that it would require a leap second every one million years to correct for the earth rotational second (don't ask me to explain what that means. I'm not a physicist. This is what's going on under the hood of an Atomic Clock.).

All of this means that the second is not arbitrary and thus, neither is the meter, which is the distance traveled by light in 1/C of a second (C being the speed of light). Alternatively, the second will defined by it's place in this equation.

Both the speed of light and the... whatever it is with caesium-133... are going to have the same outcome anywhere in the galaxy. It's like in "Contact" when the aliens used a sequence of pulses that corresponded to the prime numbers... no matter which base method you count in, the prime numbers will always denote the same value (You have the same amount of "pulses" counting to 7 in base 10 as you would counting in Base 7 (even though there 7 is actually written as 10) or Binary (written as 111).

Like wise light and atomic clocks can be used to find alien!distance and alien!time with respect to our own by doing the math.

Now, you could also make a Stardate system where time is kept in multiples of 10 seconds, but the reason we do not do that with time because the clock is set to the rotation of earth, which does not happen in a multiple of 10, but you could do that if you want to take time off a day-night cycle. It's like time zones. You could say the East coast of the U.S. is 13 hours at behind Tokyo so when it's midnight in Japan, it's 11 A.M. in New York OR you could say it's Midnight in Tokyo and Midnight in New York at the same time... it's just that Japanese Midnight is a lot more darker than New York Midnight.

Edit: Forgot to mention that your initial premise of the length of a meter is that it's calculated from C rounded to the nearest whole number, when it's in fact calculated to C with no rounding.

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  • $\begingroup$ Seconds are just as arbitrary as meters. A second is 1/(24*60*60) of Earth's rotational period. A meter is 1/2e8 of Earth's minor axis. We've since redefined both to be exactly measurable based on some physical phenomena, but to be "close" to their original values; c is 299792458 m/s so that the resulting meter would be very nearly a "classic" meter. If we were designing units from scratch, I'm sure we'd choose a more sensible number than 299792458. Even temperature is arbitrary, since it is based on Earth's atmospheric pressure. $\endgroup$ – Matthew Feb 20 '20 at 18:06
  • $\begingroup$ @Matthew: Not Kelvin. That's from a fixed point (absolute 0... all other temperatures correspond to Kelvin (the change one degree C is the same difference in value as the change of 1 degree K. K is defined by the Boltzmann Constant, which as the name suggests, is a constant value). $\endgroup$ – hszmv Feb 20 '20 at 18:17
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    $\begingroup$ for its zero-point, yes, but its scale is still somewhat arbitrary. $\endgroup$ – Matthew Feb 20 '20 at 18:25

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