The one that I sometimes think about how useful it would be to have is Vernor Vinge’s bobbler. For those unfamiliar with it, a bobbler creates a perfectly spherical, perfectly reflective shell. At the time of its creation, the lifetime of the shell is determined, and it is absolutely impervious and immutable until that time has passed. Also, time stops entirely for whatever is inside the shell. This has many peaceful uses–protection during vehicle crashes and other dangerous situations, preservation of fresh foods, storage of artifacts, one-way travel into the future, etc. It can also be used as a weapon–if you want someone out of the picture, you can bobble them up for a hundred years (or a hundred thousand, or a hundred million) and they are effectively dead form your POV. Or if you wanted them really dead, just bobble their head, heart, or such. You could crash airplanes by creating a number of small baubles just in front of their jet engines. Or you could just bobble it (or a tank, or an aircraft carrier) into a thousand spherical pieces.
(I also imagine something like an anti-bobble, where time passes at an arbitrarily high rate inside the shell. You could use this to turn any radioactive ore into a nuclear bomb–simple anti-bobble it and allow a few billion or trillion years to pass inside. When the shell pops, all the energy from the decaying atoms is released at once.)
So, favorite tools/weapons/technologies from science fiction? Never mind for the moment if the technology violates laws of physics or not.
I think I mentioned this in the other thread, as a counterpoint to the bat’leth, but the Mimbari ceremonial melee weapon was basically just a quarterstaff. Good old Big Stick. Except that they applied their Old One-level technology to improve it: Not making it a Laser Stick or a Stasis Stick or Psi Stick or anything silly like that: Just making it fold up to fit conveniently in a pocket.
Lazy Guns - Banks,* Against A Dark Background* - the Infinite Improbabilty Drive of person-portable WMDs - random effects with a barbed sense of humour
Possible Sword - Miéville, The Scar - a one-person sword storm with a clockwork motor.
The hypometric weapons from the Revelation Space series. They cut out a variable-sized spherical chunk of space and… disappear it. It’s not clear where the sphere goes, but it’s probably a billion years in the future or a billion light-years thataway or something.
It’s of course useful for disabling enemy ships by removing their engines. One might do this in a more or less catastrophic fashion, depending on if you wanted the occupants to survive. One can use it defensively as well, by subtracting out that incoming missile.
But you could, in principle, also use it for more mundane uses, like not having to get up to take a shit. Just watch your aim.
I always liked Larry Niven’s Variable Sword – a piece of wire enclosed in a stasis field. You can make it longer or shorter by unspooling different lengths before applying the field. It’s ultra-thin and can’t be deflected, so it cuts through anything. It’s absurd as a weapon in long-range fighting, since anyone with a gun (futuristic or not) can just shot you, but it has an impeccable Cool Factor.
There was nothing like it, until Star Wars came out and gave us the Light Saber. I’ve always felt that the Variable Sword was the closest thing to the light Saber in actual fiction pre-SW, and have wondered how a duel between fighters wielding each weapon would play out. Variable Swords don’t cauterize like Light Sabers do.
In the only SW EU novels that I’ve read, Timothy Zahn’s Thrawne trilogy, Zahn explained lightsabers as being exactly like a variable sword. It was only later writers that made up the whole mystical, magical crystal explanation.
In the films (which are all that count, I submit – anything in the novels can be tossed out by things done later in the films*) no explanation is given, and the name “light saber” suggests that this is some weird electromagnetic effect. Zahn, I suggest, read the Niven books, as I did. Dunno about the Magical Mystery Tour Crystal thing, never having read those novels.
*It’s happened before, more than once. In the first Star Wars novel by Alan Dean … uhhhh, George Lucas, Senator Palpatine is a weak-minded fool used as a puppet by the Dark Forces of the Empire, not the mastermind himself.
As far as being useful as a weapon, the Long Guns from Schlock Mercenary are quite effective. With nothing but the coordinates of your target location, you can project a blast roughly equivalent to a small nuke from anywhere to anywhere… including from a hidden outpost at a random location in the Galaxy, to a point of your choosing inside your enemy’s shields and armor.
At least, that’s the version wielded by the protagonists, who currently have control of a few hundred of them. But LOTA has one that works on the same principle, except instead of being equivalent to a small nuke, it’s powerful enough to turn a decent-sized asteroid into a rubble field.
Damn me for reading L. Ron Hubbard’s Mission Earth but I thought his depiction of the galactic ruler’s castle was interesting. It was offset in time so if an enemy tried to attack it, the time variance would cause the assault to miss.
Psychic Paper. Not an ultraweapon/tool, but very useful to have just when you need to get past the police blockade and back to your TARDIS.
Never much cared for the magic wand use of the Sonic Screwdriver, tho.
Babel Fish. Yes, it was designed. Proof that God doesn’t exist.
Another type of really useful magic tech is the Star Trek universe viewscreens. Magic I say because of the way they’re shown to be used. In ST-IV:TVH, Gillian summed it up well: Lots of stuff about whales and whaling and flying and stuff. “Captain, I have the whales.” “On screen!” “You can do that?!”
If you turn your target into a monoatomic gas, they will explode and kill you if you’re at normal pistol-style raygun range. Doesn’t sound very useful.
Niven’s disintegrators tended to work more slowly than the Hollywood version, gradually peeling layers off of the surface of the target. They were used against fixed objects more often than people.
In an industrial application, you obviously don’t want to disintegrate your raw materials faster than your refinery can process them. When you drive a car, you don’t burn the entire tankful of gasoline all at once. You control the input, in order to produce the desired output.
Niven’s best invention was the teleportation system in World Out Of Time. The most sophisticated version was a medical device that could remove plaque from your arteries, or toxins from your cells, without damaging the cells. On a more mundane level, it was used to create a waterless, self-cleaning toilet with a self-cleaning xylospongium. That, my friends, would be a great boon to humanity!
Of course, if you did want to use your disintegrator to maximum destructive effect, you’d use two beams, one set to suppress the electron charge and one set to suppress the proton charge, aimed at two slightly separated points, with the effect that, in Nessus’ words, “a current would flow”.
This version of the disintegrator is the reason why one of the contested worlds in the Man-Kzin Wars ended up being renamed “Canyon”.