Complex Numbers

Luna Ticks

It's refreshing to find a science article that seems to get the facts straight (though necessarily simplified). Surprisingly, it's from CNN.

    Why scientists say we need to send clocks to the moon — soon  

Before I get into it, though: no, time is still not an illusion. It's just tricky. This is analogous (but not exactly so) to answering a question like "How long is this iron rod?" when the answer depends on temperature and other factors, and probably can't be answered past a certain degree of precision.

On the lunar surface, a single Earth day would be roughly 56 microseconds shorter than on our home planet — a tiny number that can lead to significant inconsistencies over time.

Sure, that doesn't sound like a lot. Over one (earth) year, it only adds up to about 2 hundredths of a second. But they're talking about long-term effects, and highly precise instruments.

Never mind that the length of a year (and a lunar month) change slowly over time, too.

Scientists aren’t just looking to create a new “time zone” on the moon, as some headlines have suggested, said Cheryl Gramling, the lunar position, navigation, and timing and standards lead at NASA’s Goddard Space Flight Center in Maryland. Rather, the space agency and its partners are looking to create an entirely new “time scale,” or system of measurement that accounts for that fact that seconds tick by faster on the moon, Gramling noted.

CNN calling out other sources' headlines for being misleading probably falls under "irony."

Astronauts on the moon, for example, are going to leave their habitats to explore the surface and carry out science investigations, she said. They’re also going to be communicating with one another or driving their moon buggies while on the lunar surface.

It should be obvious that they can't exactly use Google Maps to navigate. I have no idea if it would even be technically possible to set up an equivalent GPS array for the moon. Even if it is (our natural satellite's gravity field has been described as "lumpy"), I imagine the cost / benefit analysis might not work out.

GPS comes with its own time issues, too, having to do with relativistic effects, which the article notes later. And it requires a great deal of precision.

General relativity is complicated...

Ya THINK?

...but in broad terms, it’s a framework that explains how gravity affects space and time.

Eh, fair enough.

The article goes on to explain quite a bit more, fortunately mostly in plain language.

Then it gets into the bit I really wanted to address:

Accurate clockwork is one matter. But how future astronauts living and working on the lunar surface will experience time is a different question entirely.

On Earth, our sense of one day is governed by the fact that the planet completes one rotation every 24 hours, giving most locations a consistent cycle of daylight and darkened nights. On the moon, however, the equator receives roughly 14 days of sunlight followed by 14 days of darkness.

If we don't doom ourselves or give up entirely, this won't be the last time such adjustments have to be made. While there are robots on Mars now, there's always been talk about sending humans there. As I'm sure we all know, a Martian "day," (which they call a "sol" to distinguish it from our familiar 24-hour cycle) is longer than 24 hours, but not by much. As a reader (and sometimes writer) of science fiction, I've often wondered whether we'd keep our circadian rhythms there, or try to adjust them to the Martian day/night cycle.

Considering that any Mars colonies will be entirely indoors, and probably underground, I could see it going either way. In a way, Mars is harder than the moon to figure out this sort of thing, because it's much closer to the cycle we're used to.

Not to mention we'd have to answer these questions for any other planet we choose to visit. (Please note that this isn't an entry about whether we could or should. Mostly, I very much needed to make the pun in the title.)

I mean, sure, the article mentions this sort of thing, too, but without details. Guess I'll have to do what other writers do and just make stuff up.