Babies Born on Mars

…and on Venus, of course, they’ll just die.

Science fiction has addressed this problem often. There are some regular standard solutions.

In the Honor Harrington series (by David Webber), the main characters live in a star system with three habitable planets, each with its own day length and year length. They use the Earth standard as T-years (terrestrial), etc, then make separate clocks/calendars for each planet. One character grows up on a planet with a year that’s about 18 T-months. Ages and such are given in two standards - the local and the reference standard. Sounds like that will be fairly typical as long as Earth is the seat of our culture, history, and meaningful government, etc.

As for how to accommodate the extra seconds, minutes, hours etc in a “day”, that varies, but would seem to depend on the local equivalents. For instance, here on Earth, people living in the Arctic Circle and who have 6 month periods of light and dark don’t count days by light and dark. They count by 24 hr periods, and go about their business on a similar schedule to everyone else, they just sleep when it’s light outside, or work when it’s dark, depending on necessity. What makes you think it has to be different on, say, Mars? Especially as long as humans are constrained to living indoors or wearing pressure suits to go outside.

If we eventually move to planets with a habitable environment, then you ask the next question - how close is their system to Earth’s? If it is as close as Mars’, then maybe it makes sense to tinker with time equivalents (like the second) so they stay somewhat similar. However, what if the planet has 6 month long days, and 15 T-year years? Will the locals want to use local divisions? Or are they just going to use Earth time divisions and say screw the local conditions? I know, with those conditions it seems unlikely the planet would remain habitable. The point is when do you make a decision point and say that shifting to local conditions is ridiculous, let’s use standard time/day/years, and when do you say we can tinker with the designations and “fix” them to use the local divisions?

Not for nothin’ but shouldn’t we work out the whole newton/foot-pound conversion thing before we start worrying about birthday conventions?

I mean, we can’t even hit the damn planet!

Naw, the Climate Orbiter hit the planet alright…just at the wrong angle.

As for the the Polar Lander, it was zeroing in on its appointed landing site just fine but a sensor misinterpreting a vibration from the legs extending as the probe hitting the surface caused it to fall to the surface at a rate of speed somewhat beyond its design capabilities.

:slight_smile:

I can’t believe no one has wished me a happy Mercury birthday. I’m 118 years old fer chissake. That’s OK, you have until mid-November to do so.

Well, “year” and "day are mutable concepts based on what planet you’re on, but perhaps seconds, minutes and hours won’t be. There will come to be occasions when folks from Mars will visit family on Earth, and Grandma will ask Junior how old he is now. If he answers in hours, then someone can whip out a calculator and do the math (1 Earth year = 365.24 Earth days = 8765.76 hours). Either that, or you can simply do what Stupendous man suggested, and just have a simple conversion factor to do the same thing.

Also, I agree with manhattan, don’t go redefining the second to conform to local planetary standard, there’s way too many important equations that depend on “second” being a universal standard. Just think of if: every time folks would land on a new planet, they’d have to update their physics textbooks…

If you’re going to come up with a local clock, that’s fine, just don’t redefine “second”.

Why would they HAVE to do anything? They could work it out however is most convenient for them. Let them worry about it, I say. I have my own problems.

Heinlein’s Podkayne of Mars deals with this, too… The main character and narrater starts off by saying that she’s nine years old, and her parents think that she should be getting married soon. Throws you for a loop, until you remember that Mars’ years are twice as long as ours.

For Mars, I suspect that we’ll just produce an adapted calender with 24 months and a little longer day, since it’s so close to Earth’s. I imagine that the colonists of each planet would have to decide for themselves.

And Lance, happy Mercday. Eat your ice cream fast, before it melts!

I can’t believe some puerile, smartass newbie hasn’t jumped in here with the obvious answer to this conundrum.

Guys, Mars ain’t no place to raise your kids. In fact, it’s cold as hell. And there’s no one there to raise them, if you. . .

What the hell does he sing here “did,” “dig,” or “you’re dead”?

Oops, one just did.

Sir

One second is: 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 cesium-133 atom.

Bwah?

The orbit has NOTHING to do with the length of the DAY.

It has to do with the length of the YEAR.

The day is how long it take to revolve around its axis.

Two completely different beasties.

Now, another planet having a day that’s exactly the same as Earth’s is unlikely - Mars doesn’t, though it’s only off by 37 minutes - but:

a) That doesn’t preclude using a second, as currently defined on Earth as the basis for ‘Universal Space Time’, since SOMETHING will have to be used - even minutes, and hours could be left alone;

and

b) This has nothing to do with the orbit.

Carry on.

Science Fiction can be fun, can’t it?

No-one would live long on Mars. The Human body would soon fail to function properly under conditions it did not evolve in.

No feasible idea for an off-world habitat that I’ve ever heard of addresses differences in gravity and magnetic field strength.

The OP’s “baby born on Mars” would soon be a baby dead on Mars.

Now if you were to increase Mars’ mass and geologic activity by, say, pummeling it with every asteroid, comet, and spare moon you could get your hands on…

Actually, the orbit does have an influence on the time between one noon and the next.

Imagine a plant with a sidereal day of 24 hours (that’s the time for one rotation, as viewed from a long way away, like the distant stars).

If it has a very short year, say 72 hours, as do many of the recently discovered extrasolar planets, then in 24 hours it will have travelled 1/3 of the way around the star, so the position of the sun is still 120 degrees from where it was 24 hours previously. The time from noon to noon in such a situation would be 36 hours.

As the orbit gets larger, and the year gets longer, the length of the noon-to-noon day gets shorter, with a limit of 24 hours.

Bill