Have you ever taken an international flight and as you are starting to put away your book or laptop because the plane is getting ready to land, the pilot comes over the PA and tells you “welcome to your destination and the local time here is 2:15 pm.” Maybe if you cross the International Date Line or if it is a particularly long flight they give you the date too. Now imagine its 1000 years in the future and you’re on a flight to another planet and somehow they still manage to pack everyone into the ship like sardines, but as you approach your destination the pilot comes over the PA and tells you that its 26:30 pm and its Friday the 4th of Clarke.
Time is a very slippery dimension, the other three dimensions can be measured with a tape measure or even just a piece of string for comparisons sake. But time is measured with watches or sundials. Although time can’t really be seen, the passage of time can be, when watching plants grow, or friends age. Another clear example of the passage of time is continued cancellation all of the good scifi shows *cough* Firefly *cough*. I spent a few weeks reading and thinking about the concept of time and its use in various scifi universes, then the other night I watched the movie Serenity. There is a line near the beginning of the movie, as they’re getting ready to rob the bank which shows that Joss Whedon actually thought about the issue of time zones on other planets when constructing the Firefly Universe. Zoe says to Mal “We should hit town right during Sunday Worship, won’t be any crowds.” I appreciate the fact that there isn’t much dialogue spent on the discussion of time differences between planets since it would most likely not add anything to the story, but this line makes me appreciate Joss Whedon’s writing on another level.
In the real world, this issue of time differences between planets has already started to be taken into account over at the Jet Propulsion Laboratories (JPL) in Southern California. Over the past few
With NASA tentatively planning to put people on Mars by 2030 the issue of having to deal with a shifting work clock won’t be a problem.
Let’s assume that this planet is habitable and people have been living there for a few years as a fledgling colony. Let’s say, you’ve arrived to establish a new way of keeping time on this planet because 26:30 on the 4th of Clarke sounds like something from a bad science fiction blog. Now, you’ve got a couple of options, you can either; 1) start an entire time system based on whatever you want, or 2) you can continue to use the
Either direction you decide to go, you might follow the path that got us to our standard of time on Earth today. It’s not completely clear where the concept of a second came from. We do know, that by the late 16th century clocks were starting to display minutes and that it wasn’t until Christen Huygens in 1656 created his pendulum clock with a pendulum just short of a meter long that clocks were able to keep time well enough to track seconds. In 1832, Carl Friedrich Gauss proposed the second as the base unit of time, and during the 1940’s the second was eventually defined as 1/86,400th of a mean solar day. Although the rotation of the Earth is not an extremely stable phenomenon due to tidal friction and the rotation of the Earth gradually slowing. Because of this, the definition of the second was changed to the fraction of 1/31,556,925.9747 of the tropical year of 1900. This definition was then superseded by the current definition, due to the inherent instability in the measurement. It was decided that we would use a natural reproducible phenomenon to define the second instead. The standard Earth Second that we all use today is officially defined by the International System of Units as “the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of a cesium 133 atom.” Each of these 9 billion plus transitions can be measured by an atomic clock. The standard second is then set by a group of atomic clocks based around the world which “vote” on atomic time and set the standard. The number of transitions was chosen to represent the second that we already had at the time.
This brings us back to the issue of figuring out what to do with time on your new planet. Since the second is effectively arbitrary, there is no real need to continue to use it if you are going to be creating your own new form of time. It is also important to point out that the Earth Second is now just multiplied by 86,400 to add up to one standard day. This has effectively left us with a time standard that only makes sense for Earth. So, you’ve decided to do away with the Earth Second for your new planet and forge ahead with your own second.
The first step is that you need to figure out how long a day is on your new planet. Well, there are a few ways you could do this. You could simply use a stopwatch and time how long it takes to get from sunrise to sunrise, but you’ll have to do this for at least a year and preferably several years to get a precise mean day length. Although, this will lead to your day still being based on the Earth Second and you don’t want that you want your own second. So instead you get out some charts and calculate how long it takes your planet to travel its orbit around its star. Then from here
You’ve done it! It might be a mess but, you have your very own new second for your new planet. You can get some new watches made up, you issue new clocks to everyone, and it’s great. Then you realise that you’re still using this weird Julian calendar thing that doesn’t make any sense. You’ll have to read my next post to figure out what to do about that.
Thanks for reading for now and let me know what you think.