Did you know a lot of planets revolve at a rate exactly relative to how fast they rotate? Due to the gravity of their sun or suns, they do the same thing our moon does to the Earth: they only ever show it one side. That means one side of these planets exist in perpetual darkness, while the other side knows nothing but continual light. The popular theory is that if life existed on these planets, it would have to dwell on the thin inhabitable strip where it would have access to both light and darkness.
One of my favorite dead authors knew about this phenomenon, developed or fleshed out that theory, and aptly coined the term ‘ribbon world’ for this kind of planet. Isaac Asimov was both a student of science and a pioneer of science fiction, and anyone interested in either knows how brilliant the guy was. One of my favorite living writers wrote a post that mentioned this very subject recently, and I would be remiss not to give a shout out to him as well. David Kelly is one of the few people that can make my mind feel like it got left behind a station or two ago when he starts to explain certain subjects. If you want to know way more in depth information about space and technology, he’s the guy to check out.
If you want to hear what little I have to say about it here, just keep reading. The concept of the ribbon world has long fascinated me, and the theory that life can only exist in that thin strip where darkness borders light on these planets has always made me wonder.
Our own ocean floor may throw a monkey wrench into this theory, as do whatever organisms that manage to survive underground; but we’re not here to talk about how wide or narrow of a band the possibilities of life exist within. We’re here to talk about the moon, and how it’s slowing us down.
The planets that don’t spin any faster than they revolve don’t have moons. That’s why they are revolving and rotating at the same rate; the sun is sort of all they’ve got, so far as gravity goes. A planet needs at least one moon to offset its sun’s gravity, if it wants the experience we call day and night. Otherwise they get the land of the day and the land of the night; half the planet is always sunny and the other half is always dark.
We call the side of the moon that faces away from us the dark side of the moon, a saying which we already discussed and dispelled in ‘The dark side of the moon isn’t actually dark!’
It just faces away from us, and we’re just really self-centered.
In our case, it’s actually the moon that keeps our planet from existing in half darkness and half light perpetually. The gravitational pull that it exerts on the Earth makes us spin at a different speed than we rotate, thus giving us the experience of day and night. It also causes the tides, and certain claims of transformation that vary widely in their outrageousness and believability.
But that’s not all the moon is doing.
It’s slowing us down too!
See, the Earth used to spin faster. It is the moon’s constant influence that slowed us down to the speed we’re at now, and which continues to do so. Although you might live a thousand years and never notice a difference, the truth of the matter is the days are getting longer. That gravitational pull is still slowing us down, and adding a tiny bit of time to the day each day that passes.
By tiny, I mean infinitesimal. Science estimates that the day will be about two milliseconds longer in a hundred years, just like today is about two milliseconds longer than a day was a hundred years ago. That’s not much from the perspective of a lifetime or ten, but it doesn’t change the fact that the days are getting longer.
When this was first discovered, they got it backwards. Scientists looked out from Earth, perceived the moon as speeding up in its orbit, and concluded that the moon was going faster. It’s like when you’re sitting in your car, about to pull out, and another car pulls in or out next to you; for a moment of sensory confusion, you might think you’re moving even though you haven’t started pulling out yet.
Yeah, like that; only on a way bigger scale.
The moon wasn’t speeding up, of course; it just looked that way as we slowed down. After a few more measurements were taken, and the rest of the galaxy was taken into consideration, the proper conclusion was arrived at: the days are actually getting longer!
Don’t try telling this to an old person. Almost all of them swear that the days are getting shorter, but that’s another misperception that comes from having a fixed point of view. The truth is that a year seems like forever to a ten-year-old, because they’ve only lived ten of them. An eighty-year-old might see the years as flying by, since one of them only represents one eightieth of their lifetime. I tried to explain this to the adults who kept complaining about time going faster, back when I first understood it. I was around ten years old, which only makes sense; let’s hope I haven’t changed my stance later, and abandoned that childhood logic for a more senior but completely inaccurate perception.
This isn’t the only surprise the moon has up its sleeve, it turns out. There’s one more thing that might be cause for a person who plans on living forever to worry about, although it too will take some serious time to play out in whatever way it’s going to. Like a child that has grown up healthy, the moon is moving further from the Earth as time goes on. The orbit it has followed all this time is not fixed, unless it’s fixed in some kind of outward spiral; the more time that passes, the further away that orbit gets. Sometimes it’s closer to the sun than it has ever been, and other times it is further away from the sun than it has ever been; but every day the moon is slowly inching its way away from Earth.
We don’t know what will happen once it gets far enough away. Will the tides get less extreme? Will werewolves be able to resist the urge to turn? How far away does the moon have to get before we start to notice that its influence is diminishing? And, perhaps most importantly…
What if the moon goes away someday?
Space is a big place, and even planets have been known to change their orbits over time. What happens if the moon gets so far out there that another planetary body pulls it in with its gravity, or smashes into it so hard it knocks it into the sun? Do we lose our experience of day and night? Will we all have to live on the thin inhabitable strip on the border of ‘day land’ and ‘night land’ just to survive?
Hopefully we will be comfortable traveling space by the time any of that happens. Or maybe we will just make a synthetic moon to replace the organic one, and keep the tides and the orbit consistent. Maybe that moon will be better than this one, and won’t put so much of its energy into slowing us down. Our best bet is probably the first scenario, since the moon isn’t the only thing that plays a factor in the Earth being livable.
In fact, there are already a bunch of spots on our planet that are not tenable to human existence. Nature made a few places difficult to deal with, but humans have made an incredible contribution when it comes to making the planet unlivable. Not only that, it all happened in the last hundred years!
You might think it’s a non-issue, and maybe it is; but there are a few questions we have to ask ourselves when it comes to nuclear energy and weapons. How many places can we make into radiation hotbeds at the rate we have been, without putting an expiration date on our species? Even if we do figure out how to live in space comfortably en masse, do we really want to be forced to because the planet we came from has been turned lethal to us by us?
Shouldn’t we learn how to clean up the old stuff before building new stuff? And should we really be building new nuclear bombs and power plants? I don’t know for sure, but I do think about it from time to time. It’s a thought that hurts to think, so we’ll talk about it next week in a post called…
‘We’re running out of places to live!’
I hope you come back for it!
Thanks for reading!
All the best,