Has this ever happened to you? You’re living on a perfectly good planet in orbit around a perfectly acceptable star—and then suddenly, the neighbourhood goes to crap and you have to move. For a lot of people, this means marching onto space arks.
Recapitulating Noah on a cosmic scale is such a pain, though. All that packing. All that choosing who to take and who to leave behind. And no matter how carefully you plan things, it always seems to come down to a race between launch day and doomsday.
Why not, therefore, just take the whole darned planet with you?
(Warning: spoilers for books that are all insanely old venerable.)
Of course, this raises the question of how to do this without destroying the world. You could just slap rockets on one end of the planet (and at least one author did) but the side effects of that method could well be…undesirable. Authors have wrestled with the problem and come up with answers ranging from the utterly implausible to the somewhat less plausible.
For E. E. “Doc” Smith, the solution was easily enough. Simply have supremely intelligent aliens provide humans and other races with the means to negate inertia, through the use of engines that could be scaled up without limit. Put down on paper like that, it seems so obvious1 . To quote A Mighty Wind, “You would make that conclusion walking down the street or going to the store.”
But…even though shuffling planets into stable orbits in Goldilocks zones would be a wonderful first step towards terraforming, Smith’s characters instead focus on moving planets into Goldilocks zones to smash them into other planets inhabited by nogoodnik species. Nothing says hello like a planet in the face at half the speed of light, unless it’s a planet of negative matter in the face, etc.
Smith was writing about a cosmic war. Stanley Schmidt’s Sins of the Fathers involved an unfortunate industrial mishap in the core of the galaxy, one that converted the Milky Way into a Seyfert galaxy (which were all the rage back in the 1970s). The Kyyra (the aliens responsible) had been methodically working their way through the Milky Way giving as many races as possible the means to escape. Unfortunately for Earth, the means by which the Kyrra chose to do this was time-consuming; by the time they got to us, a lethal wave of radiation was very nearly upon the Earth.
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The Consuming Fire
Rather remarkably, given that the setting does have faster-than-light travel (necessarily, because otherwise the first warning Earth would have got that a lethal wave of radiation was on the way would have been the arrival of said lethal wave of radiation), the Kyyra don’t simply slap a Smith-style FTL drive on the Earth. Instead, they use a much more conventional (although highly advanced) means of reaction propulsion: big-ass rockets on the South Pole. Schmidt helpfully provided the math arguing that one could attach a rocket to Earth sufficient to accelerate it enough to save the planet without also rendering it lifeless in “How to Move the Earth” in the May 1976 Analog. Well, sorry…
Larry Niven’s A World Out of Time returns to the war theme. It also marries Smith’s love of spectacle with Schmidt’s desire for a patina of plausibility. The Solar System of several million years from now has been radically transformed. The Sun is a red giant well ahead of schedule and the Earth is in orbit around Jupiter. How did this happen?
[Highlight for spoilers]: Niven postulates a humongous fusion rocket. But rather than stick it on the Earth, with all the issues that would raise, he places it in Uranus, then uses the gravity of the dirigible planet to move the Earth. Enemies of the Earth had used similar methods to hurl a planet into the Sun, thus the premature red-giantism.
[End spoilers.]
As it happens, while we seem to be short on universal wars and galactic-scale mishaps, there is at least one reason why we might want to think about how to move the Earth2 . Stars like our sun grow brighter as they age. Not terribly quickly—about one percent per hundred million years—but enough that the Earth may be uninhabitably hot in just a billion years (plus or minus). Given that the Sun won’t become a red giant for another five billion years, that seems … wasteful. Why not simply move the Earth farther from the Sun to compensate for the increased luminosity?
Thanks to people like D. G. Korycansky, Gregory Laughlin, Fred C. Adams (authors of Astronomical engineering: a strategy for modifying planetary orbits) we have some idea of what moving the Earth might entail. It turns out to be surprisingly reasonable (bearing in mind “it” is moving an entire world literally the size of the Earth): a suitably large intermediate body (a main belt asteroid or a Kuiper Belt Object) is used to transfer momentum from Jupiter to Earth. Jupiter drops a little; the much smaller Earth rises away from the Sun by more. One encounter every six thousand years might be all that’s needed3 .
It would be tremendously cool if we had evidence of a Galactic Club in the form of regular adjustments in Earth’s orbit (if only because if the Earth had been moved over the last few billion years, it would help explain the cool sun problem). Rather irritatingly, when I asked around I was assured we’d be able to tell if someone had been engineering our orbit and that there is no such evidence. How vexing. Really letting the side down, Galactic Club4 .
This is all rather academic for a species that thinks in terms of weeks or months, but still, we might not be the only technological species to occupy the planet over the next billion years. Perhaps one of our replacements will have the necessary time-binding horizons to get the job done.
1: It does seem a bit odd that inertialess matter travels at superluminal speeds and not the speed of light. Presumably the handwaving math would explain why it works like that.
2: Two. “BECAUSE IT WOULD BE AWESOME” is also a valid reason.
3: Or, if you don’t like the idea of regular near-misses from dinosaur killers, there’s also the option of much more frequent encounters with smaller objects. One wonders if one could use a similar method to shuffle worlds like Mars and Venus into more useful orbits. And if any SF author has set their stories in a well-managed solar system, cultivated like a garden… No recent examples are coming to mind, but my memory is notoriously poor.
4: Lots of SF uses one impossible idea to good effect so if you can hang a story off that idea, feel free to use it. Ideas are cheap.
In the words of Wikipedia editor TexasAndroid, prolific book reviewer and perennial Darwin Award nominee James Davis Nicoll is of “questionable notability.” His work has appeared in Publishers Weekly and Romantic Times as well as on his own websites, James Nicoll Reviews and Young People Read Old SFF (where he is assisted by editor Karen Lofstrom and web person Adrienne L. Travis). He is surprisingly flammable.
[1]It does seem a bit odd that inertialess matter travels at superluminal speeds and not the speed of light. Presumably the handwaving math would explain why it works like that.
[2]Two. “BECAUSE IT WOULD BE AWESOME” is also a valid reason
[3]Or, if you don’t like the idea of regular near-misses from dinosaur killers, there’s also the option of much more frequent encounters with smaller objects. One wonders if one could use a similar method to shuffle worlds like Mars and Venus into more useful orbits. And if any SF author has set their stories in a well-managed solar system, cultivated like a garden... No recent examples are coming to mind, but my memory is notoriously poor.
[4]Lots of SF uses one impossible idea to good effect so if you can hang a story off that idea, feel free to use it. Ideas are cheap.
A tow rope and a friend’s old transit van? That is how I move everything else, has anyone tried it? You don’t know it won’t work until you try it.
First, put furniture casters under the earth, to make it easier to get started. Ask Archimedes for his lever.
David Brin discusses moving the Earth in this Youtube video https://www.youtube.com/watch?v=Ai8x-ZqjXPc&feature=youtu.be via a method not discussed above (he doesn’t trust momentum transfer via asteroids, due to the “oops, there goes the ecosystem” possibilities).
Niven’s method is certainly elegant, as is the asteroid method. As often with Niven I’m not sure it’s possible with currently known materials.
The thing about all these ideas is that they require a functioning, unified technological society to exist for millions of years. Given that, isn’t it likely they will come up with some much better solution we haven’t thought of?
PS I have a dim memory that Greg Bear in Moving Mars had the following idea. The properties of every particle in the universe, including its position, are defined by a set of parameters. If you can tweak the parameters that define position you can move the particle, or set of particles, instantly. Now scale up to a planet. Simple!
Lift with your legs.
Did Niven ever describe how the Puppeteers got their planets moved into a common orbit and away from their sun?
For a well managed solar system, we don’t need to look beyond the authors in this article. Niven’s Pierson’s Puppeteers have a bunch of planets sharing an orbit around their sun to use as extra farm land.
@6 I see our minds went in the same direction. Unless he revisited it after Ringworld Engineers, it was just handwavy gravity control.
Don’t you hate it when a nice solar system gets so gentrified that you can’t afford to keep your planet there?
I’ve always liked World Out of Time just because it was the first book I remember that had that kind of large-scale reengineering of the solar system. (I know I’d already read Ringworld & some of the other Known Space books before WOoT, but for some reason moving planets around within a solar system just seemed more impressive than constructing the Ringworld. Which is, of course, not actually true when you compare the two projects.)
Anent footnote 1: SF has been far too willing to forgive silverbacks like Smith and Heinlein for failing to apply basic algebra to the negative result in the Michelson-Morley experiment.
Anent footnote 3: the third (and regrettably last) of Brian Daley’s Floyt and FitzHugh novels visits a Klemperer rosette of (17, if I recall) planets terraformed by the series’ Mysterious but Conveniently Absent Aliens.
The risk of causing another Chicxulub-style event is manageable. If we’ve attained the ability to tow rocks so that they can be used to siphon orbital energy from Jupiter, then we should also have the ability to attach motors to them so that they are sent off into the Sun (or on otherwise safe-ish orbits) after they’ve played their role to boost Earth into a larger orbit.
Even better might be to utilize Kuiper-belt objects for that purpose, as the possibility to reduce each one’s mass via a Sun-grazing orbit increases the margin of error for post-boost safety orbits. Bonus: it might create new meteor showers to replace the ones lost in each bump in Earth’s semimajor axis!
For Smith, inertialess did NOT equal superluminal. He did toss out the speed of light as a limit – but the speed something could move at when inertialess was equal to max speed it could attain using whatever propulsion limited by the friction of the surrounding material. (Oh, he also seems to have assumed the existence of an absolute reference point for velocity.) After inertia was restored, you got your original velocity vector back.
The superluminal-when-not-inertialess planets that got tossed at other planets (and at least one sun!) were from a different dimension. Unpleasant stuff.
The nut-cracker planets were cute – take two planets of roughly the same size that have opposite velocities at some point in their orbits, then use intertialess drive to put them on either side of a target planet, and turn off the drive. Original velocities restored, they plunge towards each other, crushing the hapless target in between.
Then there’s the methods for moving planets in the Skylark series – the first was ‘place the planet in stasis so nothing can move, then mount big drives on it’ (used in … Skylark of Valeron), second was essentially ‘teleport the planet’, used in massive scale in Skylark Duquesne.
Paul Birch also explored moving planets, along with other momentum transfer ideas. Orion’s Arm pays homage to him and has an archive of his papers. https://orionsarm.com/page/442
As soon as I read the title I thought “Easy, inertialess drive” only to read the article and find out I had been anticipated haha.
I know A Pail of Air is often dismissed here because of the main character’s attitude toward girls, but as a youngling I found the story impossibly romantic. Nowadays though, I wonder if something with enough gravitation to throw the Earth out of its orbit could possibly leave any life to survive on the surface, or even leave the Earth intact and not shattered.
Google tells me James Blish’s spindizzy moved on from cities to planets.
But don’t tow it with a TARDIS, that’s just silly.
Our friend Qntm has made a brief survey of the topic, as a sidebar to his How to destroy the Earth pages. One thing to think about is that it may be possible to move the Sun instead of the Earth, which even if it’s not as easy sounds cooler.
Some folks maybe missed the “(Semi-) Plausible” part? Inertialess drives and teleportation: not so much.
Note that arguably “teleport” is not a form of “move”.
@6 @wiredog I think in the later “____ of Worlds” books coauthored with Edward Lerner, it is mentioned that the puppeteers bought planetary drives from the Outsiders. Which just changes it from Puppeteer magic to Outsider magic…. :-)
Turns out the whole planet is built on an ancient Indian burial ground. A deep intimidating voice says, “GET OUT.”
Nice planet. Too bad we have to leave….
Charles Stross made use of momentum-transfer bodies to move the Earth out from the expanding Sun in “Palimpsests”.
The Earth can regulate its temperature pretty well, even with the increasing solar luminosity. The problem is that it does that through the carbon cycle, and eventually there’s not enough carbon dioxide in the atmosphere for plants to survive. The entire biosphere dies while the climate isn’t much hotter. If you don’t want to bother moving the Earth you could just grow food in enclosed greenhouses enriched with carbon dioxide, and be perfectly comfortable on the rest of the planet. Of course eventually the cycle breaks down and everything burns.
@@.-@ I also thought of Moving Mars. I’m going to have to dig that book out and give it another look.
As far as i know moving planets is not even a remotely good idea. If done wrong then could put earth in jeopardy by causing an ice age. We could however get out of an ice age by strategically putting reflective material on the moon. Only planet that could possibly be moved using almost current technology would be mercury away from the sun to be terraformed. It moves on allmost zero degree on its axis around the sun. Swivel tether large solar parachutes on the poles of mercury to collect solar winds to gently more mercury away from the sun. Problem is it could put out of wack the rest of the planets in the inner solar system including earth. So me being a mover of worlds says. Its not a good idea. Other ways to terraform planets by just giving them what they want or need. Mercury. Increase its magnetic field.with solar powered magnetic field generated satellites. Thats a start. Venus vaporize off lots of its atmosphere with lasers or microvave satellites. Afterwards it would cool enough to start the terraforming process. Mars. What does mars want. Strategic reflective material on phobos to start. To give more light and heat to mars.
ABIAN TIME-MASS EQUIVALENCE FORMULA T = A m^2 in Abian units.
ALTER EARTH’S ORBIT AND TILT TO STOP GLOBAL DISASTERS AND EPIDEMICS.
JOLT THE MOON TO JOLT THE EARTH INTO A SANER ORBIT.ALTER THE SOLAR SYSTEM.
REORBIT VENUS INTO A NEAR EARTH-LIKE ORBIT TO CREATE A BORN AGAIN EARTH(1990)
THERE WAS A BIG SUCK AND DILUTION OF PRIMEVAL MASS INTO THE VOID OF SPACE
[A. Abian, 1999]
There’s also the Velikovsky proposal to use quantum mechanics to bounce Venus from one orbit to another, using its gravitational effects to alter Earth’s orbit and rotation indirectly. Of course, that requires really big quanta. Alternately, figure out how to get Jupiter to eject another planetary mass with the appropriate vector. The details are left as an exercise for the student.
There was a story by Fritz Leiber, written back in the 50s, called “A Pail of Air.” It told of a family surviving in a makeshift shelter on an Earth torn from its orbit and pulled into deep space. One of the boy’s chores was to go outside daily in a home-made spacesuit to collect a pail full of frozen oxygen so they could keep breathing. The science doesn’t hold up well on close examination, but the tale is powerful enough to overcome that. While the story has a happy ending, the sense of claustrophobic horror that Leiber evoked in the first section stays with me to this day.
@15: Regarding “A Pail of Air” – a large object doesn’t have to get particularly close to Earth in order to adversely affect its orbit, and the tidal effects that would damage the earth drop off with the inverse third power of the distance from the Earth.
@6 – being puppeteers, very carefully would be the answer.
@@.-@,@23 — The idea of “editing” properties of elemental particles also played a significant role in Bear’s Forge of God/Anvil of Stars.
Heinlein discussed doing this as a terraforming technique in Between Planets – the characters had just come up with a space drive that let them cross interplanetary distances in a few days, and had lots of nifty features which appeared to include something like Vinge’s “bobble”, so on their way to rescue Mars from the EVIL Earth government they discuss using it to move planets to better orbits, make Venus more habitable for humans (not sure what the native Venusians, very intelligent dragon-like lizards of abnormal size who liked living in hot swamps, thought about that one), and so forth.
And Blish moved planets a couple of times in his Okie / Spindizzy series.
Isn’t there a case to be made that Between Planets is in the same sequence as Star Beast and Starman Jones? So the temporary setback at the end of BP might have been followed by Earth getting its hands on the technology and then putting its much greater industrial potential to work.
“Isn’t there a case to be made that Between Planets is in the same sequence as Star Beast and Starman Jones? So the temporary setback at the end of BP might have been followed by Earth getting its hands on the technology and then putting its much greater industrial potential to work.”
Works for me, if BP is set a few centuries before the others.
Venus is mentioned in the later books so at least Earth didn’t glass the place.
I think the Puppeteers move their planets with magic drives they’re still paying the Outsiders for. But that might be from the later “Fleet of Worlds” novels rather than the original stories.
One of Janet Kagan’s short stories had some helpful college-student aliens show up to move the Earth and Sun, along with the stubborn grandma who wouldn’t leave with the rest.
I just barely remember “Worlds for the Taking” [Kenneth Bulmer?] – more because it was one of the first sf paperbacks I got my hands on at 11 than for anything about the story. Anybody remember what their trick was?
How about a handful of turtle treats?
Yeah, any sufficiently advanced togas and towers civilization can move a planet; real masters of the universe dim the stars…
Oh, and I don’t know if it ever appeared in an actual novel or story (and it’s not technically moving a planet), but Larry Niven, in his essay “Larger Than Worlds” said that if you had a Ringworld around a sun, you could potentially add some magnetic fields to basically use the star as a jet; and by the time the star had burned away, you’d be moving at Bussard ramjet speeds.
(I have my suspicions as to whether the math would work out; and I might be misremembering a few of the details. But still.)
And in one of the later Ringworld novels, I think they equipped the entire Ringworld with a hyperdrive or some such.
Unfortunately, Bussard Ramjets turn out to be about a billion times better at drag than thrust.
The only plausible method — ignoring the sort of magic pseudo-science that is the core of much of “hard sf” — is the gravity tractor.
See, for example, Schweikart, R., Chapman, C., Durda, D., and Hut, P., “Threat Mitigation: The Gravity Tractor”, https://arxiv.org/abs/physics/0608157.
Yeah, Bussard ramjets are great if you’re writing in the 1960s or 1970s, but these days not so much.
just hire a silver-age kryptonian or three
There’s gravity drives in Michael Kube-McDowell’s Emprise series and F.M. Busby’s Long View, which would work fine when scaled up: They generate gravity without mass at any place you point. At small scale, a ship “falls” forward, dragging its own drive with it. While both IIRC only use them on starships, with enough power, you could steer a planet anywhere you wanted.
Simple and safe; any object in your path will fall into the gravity point, not hit your planet-ship.
It seems to be Earth-moving season.
hahaha I came to post exactly that!
@44 — That also reminds me (for no good reason) of Roger MacBride Allan’s Lost Earth series (Ring of Charon & Shattered Sphere, sadly left incomplete), although in that case the planet wasn’t so much moved as popped through a wormhole or something along those lines.
@44 I thought it was rabbit season.
@47 Duck season
Rabbit Season!