In an intense and non uniform gravity field, the various parts of a moving body tend to follow different trajectories, and will unless the whole structure is tied strongly enough to prevent flying apart in pieces.

This is the tidal effect, which is actually causing tides on Earth seas. It is only deformation of the structure, as Earth gravity maintains the planet integrity, but not quite the shape for the fluid parts.

In an answer to a previous question, Can spaceships really explode in space?, after attempting to give an abstract view of more traditional energy-explosion weapons, I tried to imagine another kind of weapon, based on physical laws (hopefully), and I came up with the tider.

The idea is to create in intense non-uniform gravity field near a ship to dislocate it by tidal effect. A black hole would certainly do, but I tried not to be specific (hoping physicists will not mind).

Following a comment by another user, I am now wondering whether such a weapon has been suggested in some existing SciFi work, written or film. Particularly without using a black hole for that purpose, but rather something like gravity waves, or other (I wonder whether a gravity soliton might make sense, but it may move too fast to do damage).

I looked in wikipedia, but found only an article on black holes in fiction, and another on Weapons in science fiction. they do not seem to include this idea.

Precisions added after 3 answers

I tried to ask a very specific question, as I explain in the motivation. I am not asking a long list of uses of gravity tidal effects in science fiction stories, as this is clearly against the rules of SE. I think it may be interesting to see whether authors attempt to use a physical phenomenon to a specific end.

Not respecting the spirit of the question will lead to a closing vote, with no benefit to anyone.

The question was specifically about weapons, which rules out Niven's Neutron Star story, as it is not about gravity weapons.

Though I may not have been insistant enough, I did say that I was not interested in black holes (or implicitly neutron stars) answers, as these are a bit obvious, and I knew it had been used (even though I did not remember specifics).

The gravity gun, and gravity bomb of Star Wars is a much closer answer as it does use gravity waves to dislocate ships. The one thing I do not like is that is is done with some kind of explosion. Though I did not say it explicitly, I was trying to exhibit a weapon that does not cause or use explosion.

The Ender answer is in a way the one I like most so far, as it suggests original uses of an existing (in the story) gravity based technology. The only drawback is that it remains vague, and does not seem to be based on tidal effect as asked. Another weakness is that it is speculative even in the story, which is surprising given the context. Having gravity based weapons should be expected for a culture at war that masters gravity technology.

The answer of Kyle Jones, though interesting in its diversity if lists were allowed, is based mostly on black holes, which is not what I am looking for.

Nevertheless, thanks a lot for answering, as these answers help making the question more precise, and identify interesting side issues on technology consistency.

closed as off-topic by user8719, dmckee, alexwlchan, phantom42, user1027 Dec 6 '13 at 15:58

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Requests for lists of works or recommendations are off-topic as they do not fit our questions and answers format. Feel free to ask about people's favorites in chat." – Community, dmckee, alexwlchan, phantom42, Community
If this question can be reworded to fit the rules in the help center, please edit the question.

  • Thanks for the replies. I read two of these books, but too long ago to remember. Interestingly, one answer is from Star Wars universe, which ties back to the comment that motivated my question. Apparently the question was worth asking. If anyone has a clue as to what may justify downvoting it, I am really curious to know. – babou Dec 5 '13 at 20:14
  • I am pretty sure downvote was because the question is not designed to have a single "correct" answer - any answer is equally correct. – DVK-on-Ahch-To Dec 5 '13 at 21:03
  • @DVK Thanks - This is silly. If we were doing maths and I asked, is this equation solvable, it would be considered as having a single answer, though it could possibly have many proofs. This is exactly the case here: I was not asking for a list of all occurrences of such a weapon, but only for existence of one occurrence, as I explained in the motivation of the question. As it goes, answers are few. I do not understand this SE paranoia. Why is it becoming impossible to ask some respectable questions? BTW, your Star Wars answer seems so far closest to what I tried to describe. – babou Dec 5 '13 at 21:37
  • @babou - I understand what you're saying but despite that (and I feel a need to apologise because you obviously put some effort into this question) I'm still voting to close it as a list question. The problem here isn't so much the question itself but rather the kind of answers it's going to attract. – user8719 Dec 6 '13 at 0:50
  • @JimmyShelter I understand your problem, even though there are not that many answers. I am currently modifying the question to cut down further the number of answers. I hope this may help. While I now understand the downvote for law and order reasons, I do not understand that people will not upvote, while giving detailed answer(s) to a question that is not quite obvious to everyone. Not a complaint, only a consistency issue that might be better suited for Meta. It seems that trivia have more success. – babou Dec 6 '13 at 10:30

There were definitely ideas suggested. For example:

  • Petra suggested the idea to Ender when training him (though in reality, MD weapon didn't use gravity):

    "They never tell you any more truth than they have to. But any kid with brains knows that there've been some changes in science since the days of old Mazer Rackham and the Victorious Fleet. Obviously we can now control gravity. Turn it on and off, change the direction, maybe reflect it-- I've thought of lots of neat things you could do with gravity weapons and gravity drives on starships. And think how starships could move near planets. Maybe tear big chunks out of them by reflecting the planet's own gravity back on itself, only from another direction, and focused down to a smaller point. (Ender's Game - Chapter 7 - Salamander)

  • Star Wars universe had Gravity gun (in Luke Skywalker and the Shadows of Mindor)


In the work Neutron Star By Larry Niven (1966) Beowulf Shaeffer, is sent to find out what killed two researchers near neutron star BVS-1. They were in a ship with a General Products hull which is impervious to anything apart from visible light & antimatter.

Tidal energy plays a significant role in the story.

  • The answer essentially gives away the story anyway, so I wont bother using ROT13 to obscure my comment text. While there was worry over whether something like a new weapon could get through a GP hull, it was in fact natural in that case. In that story, once Shaeffer determined the tidal cause, I don't recall it being specifically suggested that someone might deliberately employ gravity as a weapon, though I could be forgetting. – Jacob C. Jan 14 at 23:56

Larry Niven played with the idea of using gravity as a weapon. In the short story "Borderland of Sol"

space tugs haul around a quantum black hole, using the hole's sharp gravity gradient to rip the hyperdrive motors out of incoming ships, precipitating the ships out of hyperspace. The ships were then robbed at leisure, with the black hole used to eliminate the evidence and any surviving witnesses.

In the Fleet of Worlds series of novels it was strongly implied that the Puppeteers left spheres of neutronium along their escape path out of the galaxy, reasoning that the spheres would appear from a distance as a large Slaver stasis box. Any ships attempting to approach and claim the faux stasis box would be seized and ripped apart by the gravitation fields of the neutronium.

One of these spheres was encountered by Louis Wu in the short story "There Was A Tide", destroying an alien vessel.

In the novel Protector, Brennan used a gadget to collapse the gravity generators of pursuing ships into a "hypermass", another name for a quantum black hole. The ship would then either be ripped apart or fall into the hole itself.

In the short story "The Hole Man",

one character dropped a quantum black hole right through another character. Tidal effects cause extensive cell damage as the hole plummeted through the character, killing them within seconds.

  • 1
    Also, in Niven's "There is a Tide": ˙dɐɹʇ ɐ sɐ pǝʇuɐld sɐʍ xoq sᴉsɐʇs ɐ ɹoɟ ʞooʇsᴉɯ nM puɐ ǝɥ ʇɐɥʇ ǝɹǝɥds ɯnᴉuoɹʇnǝu ǝɥʇ ʇɐɥʇ sʇɔǝdsns ɔouᴉɹ⟘ ǝɥʇ – Jacob C. Jan 15 at 1:00

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