Short story by Jerome Bixby-The Holes around Mars.
Neither story would actually work as nothing can be going fast enough to orbit at just a few feet above the ground.
There is another issue that bears consideration, which is that the power throughput of electrically-powered weapons in high energy lasers (and presumably other hypothetical energy weapons such as plasma weapons, coil guns, rail guns) is low, with efficiencies that are often in 10[SUP]-2[/SUp] range, which means that the bulk of the energy delivered to the weapon is lost as heat. In terrestrial applications, that heat is transported away by forced convection into the air (or in fixed installations, by the use of thermal reservoirs such as rivers or lakes). In space applications, the only way to transport the heat away would be either radiation to the background 3.7 C microwave background (requiring gigantic radiating surfaces, which isn’t really consistent with a warship) or by absorbing the heat with a coolant which carries away thermal energy by being vented. The thermodynamics of dealing with this waste heat is a fundamental problem.
Of course, chemically powered weapons also produce waste heat as anyone who has fired a gun can attest to, but much of the excess heat is carried away by the propellant, and overall the thermodynamic efficiency of chemically-powered projectile weapons is much higher than the best estimates of projected energy or electromagnetic weapons. Rocket powered weapons, where the power source is carried to the target with the projectile rather than being all applied as a nearly instantaneous impulse at the source.
As far as combat between ships, applied velocity or kinetic beyond that need to affect an intercept is scarcely necessary. At orbital speeds even slight differences in a velocity vector are sufficient for even the lightest projectiles to breach the strongest materials. It would be sufficient to deploy a cloud of sand in the path of an opposing ship in order to render it incapable of navigating or communicating (by destroying antenna, external sensors, and any delicate systems such as attitude control systems) if not completely destroying it. Of course, the weapons you see in science fiction, such as ‘phasers’ and ‘photon torpedoes’, don’t portray any of these difficulties, just as they fail to portray many other aspects of practical space transportation or combat. But the reality is that projected energy weapons are more problematic than any theoretical advantages they provide.
Stranger
Gyrojets. Their time has come.
The problem that immediately occurred to me is that since the Moon isn’t a perfect sphere, anything in an orbit that low would inevitably smack into a hill or something and be stopped long before then.
Much as I love Firefly, the presence of conventional* guns is certainly nowhere near the least believable element. I mean, if I was going to pick fault, I’d say the least believable thing is that Wild West culture, dress and language arose again with too close a likeness to its first iteration on Earth-that-was.
Chemical-powered projectile weapons are effective and cheap - and we already know they can exist. Plasma blasters (or whatever), although common in Science Fiction, can sometimes add an air of implausibility (yeah, I know we’re meant to suspend disbelief, but it doesn’t always work).
*(Are the weapons really conventional firearms? - Mal’s gun, for example, makes a sound like as though a tiny motor is spinning up when he draws it)
No, the real problem is the speed. It looks like the required speed for a near-surface lunar orbit would be something on the order of six hundred thirty two thousand mph: you would need a gun that could accelerate a projectile to that speed in the space of, what, a two foot barrel, without vaporizing the projectile or destroying the barrel. Good luck designing that.
IIRC they’re canonically something like gauss guns deliberately made to look like old timey Wild West shooters. Which, you know, why the hell not ? These things had Class.
Kinetic bolides …
In ‘The Moon is a Harsh Mistress’ the lumies fight earth by dropping rocks on it. Well, throwing actually as they wrap them in enough iron to let the mass accelerator push them into the surface of the Earth. Mannie and the Doc who are the ambassadors to earth also travel via grain container tossed at the earth.
Calls to mind the tungsten telephone poles of Project Thor.
Even if projectile weapons remain popular, projectile weapons as we know them will be obsolete. We already have automated sentry turrets that can target and fire on their own. We have Google Glass, which doesn’t do eye tracking but will be able to in a matter of years. The military uses projectile weapons that actively track incoming missiles and shoot them out of the sky. They also have rudimentary tracking systems that can locate the source of gunfire and fire upon it. This technology isn’t exactly field-ready but it’s only a matter of time.
In the future, the idea of drawing and aiming a pistol will seem quaint. Instead, you’ll have a pistol mounted on your shoulder like the Predator. You target with your eye and think about shooting someone, and before anyone can blink your weapon has targeted, gyroscopically aimed (taking into account environmental conditions), and fired 8 rounds.
Because of this deadly accuracy and speed, actual engagements will be avoided at all cost. Consider the videos we’ve all seen of firefights in Afghanistan, where combatants thousands of feet away from each other fire at targets that they can’t see, because getting any closer would mean certain death. Take that scenario, but increase the accuracy, distance, and speed, and nobody would get within 5 miles of an armed adversary.
Or consider an armed robbery scenario – a guy pulls a gun on you, and it’s a battle of technology. The camera system in your shoulder-mounted defense shield identifies the enemy weapon as it’s being uncovered. It alerts you to the presence of said weapon, you see it on your heads-up-display, think about shooting the guy, and your weapon tracks, targets, and fires, taking out the enemy weapon before locking onto the enemy itself. Hopefully all of this happens before the bad guy’s shoulder-weapon is able to lock onto your own gun.
That’s, uh, very wrong. The correct number is about 1680 m/s (sqrt(GM/r) = sqrt(6.67e-11 * 7.35e22 kg / 1.74e6 m), or 3760 mph. That’s high, but not absurdly so: high power rifles reach 1200 m/s.
Other than mountains, mascons are a problem for low lunar orbits.
I suspect Ranger Jeff might be referring to a similar short story by Ben Bova, although I don’t recall the title. The plot is identical, though.
One of the things I love – and find hilarious – about old SF and especially SF movies is the way the intrepid explorers carry firearms with them into space. Robert Heinlein did it in his first novel, Rocket Ship Galileo. They were necessary to the plot, but he recognized that they were hard to justify.
In Jerome Bixby’s It! The Terror from Beyond Space the first space ship to Mars (which happens before the events of the story) carried guns. we know because one was fired at the unseen monster and ended up hitting a crewman instead, resulting in a skull with a bullet hole in it. Later on, when the monster shows up on board the ship, they (fortunately) still have guns to use on it. Even more alarming, they have grenades. Who the hell carries grenades on a space ship? Or even thinks about firing guns on one. With all that mayhem, it seems a little silly to be perturbed by the fact that these explorers are burning up precious oxygen by smoking, but I still am.
Similarly, in Robinson Crusoe on Mars our intrepid hero pulls out a gun shortly after ejecting onto the surface of Mars. Fortunately, what scared him was only Mona the monkey, from his own capsule. Still, you gotta wonder about carrying firearms to Mars – did they see It! and get worried that there might be monsters on Mars? (Of course, he later runs into aliens, but who would have thought THAT likely?)
It bothers me that all the above examples are from the overall best sf representatives of their era. It’s not surprising when lesser efforts still have heroes with guns on the moon.
Ray guns came to be used becausec they were cool, and suggested futuristic technology, and (in the words of the SF Encyclopedia) “left a minimum of bleeding parts to be swept up afterwards”. But my objection to them is the same as Stranger’s above – existing lasers aren’t models of efficiency. The early CO2 lasers had only a few percent wall plug to beam efficiency, with most of the used power being exhausted in waste heat, which water cooling carried away. Modern lasers have improved on that, with some laser systems having light-to-light conversion efficiency over 90%. The problem is that the thing producing the original light is another laser, with a lot less than 90% efficiency. The hot thing now is combining diode laser output. I built two systems that did this a couple of years ago. I got out a kilowatt of output, but I had a cooling water system the size of a refrigerator.
Combine that with the fact that laser cutting is often phenomenally inefficient in doing in your enemies (unless you get the wavelength right, you could waste a lot of your energy in simply boiling away his bodily fluids, rather than slashing a clean slice through his body), or that even at 99% efficiency you laser pistol is going to get REALLY hot. Or the simple fact that your ray gun will undoubtedly be carrying around a fearsome amount of energy packed into a very small space. as Arthur C. Clarke observed in The Sands of Mars – talking about a power pack for a mere flash illumination unit – this has the makings of a small bomb. I wouldn’t want to drive a nail into it.
And particle beams are even worse.
All said and done, a modern gun is simpler and overall safer than any likely beam weapon (unless you want to use it to blind people, in which case I don’t want to talk to you). It’s retro, but if I needed lethal force, I’d carry a gun. And, as Heinlein ionce said, even Captain Future will probably carry a shiv.
First off, nothing’s getting to another galaxy in two thousand years - not even a ray of light, much less a rifle slug.
Secondly, nothing’s leaving the Solar System unless it’s exceeding solar escape velocity; the slug’s more likely to be going into orbit around the Sun.
Thirdly, if it does stay in the Solar System, it can take its chances along with a whole bunch of other meteoroids which are already packed with a comparable amount of kinetic energy.
Fourthly, if it gets out of the Solar System, chances are it will never encounter another lump of matter again. It’s hundreds of thousands of years to Alpha Centauri at those speeds, and nearly all of the sphere enclosing that star and our Sun is empty space. I think it was Fred Hoyle who observed that if all of Europe were host to only three flies, the air over Europe would be more crowded with flies than space is with stars.
Obviously what we need though is some kind of radiant energy weapon of the type popular in fiction nine decades ago - the kind that might do no damage to structures but was infallibly inimical to organic life.
That’s the least believable thing? Not that cattle rustling with a space ship was profitable?
I’ve read some science fiction stories where they still have slug throwers but they use some other chemical besides gunpowder.
Crap, I forgot to do the square root :smack:
In response to some posts that mentioned laser weapons: I thought that it wouldn’t be feasible as a weapon because of both crazy power requirements and especially the inverse square law. It just doesn’t make sense to even invent personal laser weapons technology when a simple projectile gun like the ones we have today would suffice.
Sophisticated EM weapons of the future will target the wetware. Non-intrusive drouds (pleasure-center stimulators), neural/computer interfaces and electronic brain function enhancers will lead to the development of longer-range brain weapons. One can choose to make the enemy deliriously euphoric, severely inhibiting their drive to fight, or to accelerate neurological function to the point that it results in confusion/fear. With these weapons, friendly fire will be less of a problem, as they are not inherently lethal. In addition, if one uses a strong enough happiness beam on the enemy for a sufficient length of time (not terribly difficult, since the victim will not be inclined to evade the assault once it has taken effect), shutting off the beam will leave the victim vulnerably despondent. Tuning these weapons to work on non-human creatures could present a significant challenge, though.
I quite liked the tech mix. The point is that it’s frontier colony worlds where they spend most of their time. Places where there is no established industrial tech base, high tech stuff is rare and expensive, but if you just need personal tranport/plough pullers etc, all you need are horses x time with all the other stuff is a 19th century tech base with modern knowledge could manufacture.
When they go into civilised worlds, it’s all flying cars and Apple style shiny world stuff.
;)Nonsense…we’ve had 1920 style deathrays since the 1920s!