Why does sci-fi seem to have a hard-on for energy weapons?

[Formless]

Borgy, I really don't see how I can put this to you, but I don't want to have this conversation if you are going to act so stubborn about it. You have five people telling you the same things and you aren't getting it, and the main question raised by the thread has basically been answered:

Why energy weapons? The question rests on a false assumption-- that projectiles are under-represented when in fact only one specific type of projectile weapon that you wax on and wax off to is seen infrequently in older SF, and I would go so far as to say is over-represented in modern video game SF stories and possibly literature (though I'm not too interested in most modern written SF what with the back catalog of classics I could read). The main example you keep using, Star Trek, already uses a "smart bullet" style hybrid missile, that happens to have an antimatter warhead inside to increase its effectiveness; because we don't actually know that projectiles are effective against Federation shields without a warhead. They do have a deflector dish for a reason, after all: to move aside naturally occurring projectiles like meteorites, which would otherwise punch holes in the ship's hull, as depicted in "Year of Hell" on Voyager. The only evidence you have given for projectile superiority are 1) ramming works, which is a ridiculous leap when, in your own words, "4.5 MILLION ton mass of a Galaxy class" is the weight of the Enterprise D, 2) Borg drones are sometimes shown to be vulnerable to projectiles, but not their ships, other faction's ships, and then fail to address the point that its probably easier to simply issue a software patch for existing phasers than distribute a mess of new firearms which exist for a rare contingency (see "Field of Fire" where they reveal the prototype of a firearm Starfleet scrapped in favor of another phaser variation that did the same job well enough), 3) projectiles are superior in your own mind, which is circular logic and readily addressed by everyone else.

And getting back to the original question (again), why mass drivers are under-represented in older SF stories (compared to lazors and missiles) has already been answered, and you couldn't really argue the point because the historic facts speak for themselves. So I'm done. I've proven the point I came here to prove, and the rest is just a huge, barely worthwhile tangent to me. The other people in this thread can explain the relative disadvantages of slugs as well or better than I can. Ciao.

[Sea Skimmer]

Can somebody explain what the difference is between a missile and a guided projectile in space is supposed to be? How is your smart shell supposed to steer itself, if not by engines? It's not like fins and aerodynamic guidance will work in a vacuum... at that point, you've basically got a magnetic-launch missile system like we see in the Honorverse.

Indeed it'd have to be a gun launched missile with its own propulsion, something like the kill vehicle for an anti ballistic missile system with side thrusters, or perhaps if the corrections were only to be small, a ring of explosive charges as on the Dragon missile or one shot rockets as on PAC-3. It doesn't necessarily need rearward thrust. This could still make sense if the mass of the gun and the power supply is a lot less then the cumulative mass and storage requirements (which might be under high mass armor) of all the rocket motors you saved from the ammunition supplied for that weapon.

If you don't save a lot of mass, you'd sure want pure missiles because missiles could be easier to engineer and could be fired more rapidly.

Also you can add velocity to the missiles by using the ship itself as a gun, accelerating towards the target before you fire. This would of course also work with actual guns too, and the enemy can make his own reactions.

[Simon_Jester]

Can somebody explain what the difference is between a missile and a guided projectile in space is supposed to be? How is your smart shell supposed to steer itself, if not by engines? It's not like fins and aerodynamic guidance will work in a vacuum... at that point, you've basically got a magnetic-launch missile system like we see in the Honorverse.

Basically, a guided projectile gets most of its velocity downrange from the gun, while a missile gets most of its velocity downrange from engine power. The guided projectile needs less delta-v, but has to be massively overengineered to survive the stresses of getting thrown out of a cannon.

Borgy, I really don't see how I can put this to you, but I don't want to have this conversation if you are going to act so stubborn about it. You have five people telling you the same things and you aren't getting it, and the main question raised by the thread has basically been answered:

He's starting to get it, I think...

[Borgholio]

Real life nuclear bombs are pretty big, heavy things; if they fall on a house the sheer physical weight would do some real damage to that house. That doesn't mean someone would seriously consider the idea of removing the explosive package from the bomb just because the bomb "can cause mayhem simply by impacting the target."

Well yeah I'm not saying they absolutely should remove the warhead, but I was thinking about a tank-fired sabot round which requires no warhead to make a kill. On the topic of what a futuristic projectile might look like, an armor-piercing shell with a smooth, creamy center of antimatter would be quite painful, if the antimatter was released after the shell pierced the hull and broke apart.

Yes, but enough to make up for the fact that phasers deliver kiloton-per-second levels of firepower? Maybe they can do that... but we can't just assume they can do that.

Part of the problem is that a phaser is not a pure particle beam. Much of the damage it does is due to some kind of nuclear chain reaction which makes very little sense from a physics standpoint. In Enterprise, we did see an overloaded phase cannon blow the top off of something the size of Mt McKinley. That suggests kiloton-level destructive force, at least if you horribly overload it.

The point being that you really, really don't know that projectiles work better than phasers in all ways. Or that it would be fully practical to replace the phaser mount with a mass driver of comparable size and expense and get a weapon system of equal or greater effectiveness. If there are serious disadvantages to using projectiles that you haven't thought of, they could easily explain why people don't do that more often.

One advantage I see over a phaser strip instead of a phaser or mass-driver turret is traverse speed. The strips do allow for very good coverage. As a particle accelerator, they suck though. So it might be a trade off between raw kinetic force and the ability to shoot in any direction without having to turn a turret.

[Borgholio]

You have five people telling you the same things and you aren't getting it

What are you talking about? I've already conceded several points including the guidance issue and the range issue when Simon brought up his arguments. At this point, given the range of ST combat, projectile weapons are not looking very promising except vs a big, fat, dumb target such as a Borg cube.

why mass drivers are under-represented in older SF stories (compared to lazors and missiles) has already been answered, and you couldn't really argue the point because the historic facts speak for themselves.

Of course I couldn't argue that point, all the evidence backs it up. Why does ST show ships fighting at knife-range when dialogue and tactical displays give ranges on the order of light seconds? CGI and pretty 'splosions. Ok, that's a reason. How am I supposed to argue against that without sticking my fingers in my ears and humming loudly?

[Simon_Jester]

Well yeah I'm not saying they absolutely should remove the warhead, but I was thinking about a tank-fired sabot round which requires no warhead to make a kill. On the topic of what a futuristic projectile might look like, an armor-piercing shell with a smooth, creamy center of antimatter would be quite painful, if the antimatter was released after the shell pierced the hull and broke apart.

Well, the real problem you face is that somewhere between... I dunno, 10 km/s and 1000 km/s, the structural properties of any conceivable material made of atoms become kind of irrelevant, because the impact energy is more than enough to instantly vaporize the shell on impact.

Yes, but enough to make up for the fact that phasers deliver kiloton-per-second levels of firepower? Maybe they can do that... but we can't just assume they can do that.

Part of the problem is that a phaser is not a pure particle beam. Much of the damage it does is due to some kind of nuclear chain reaction which makes very little sense from a physics standpoint. In Enterprise, we did see an overloaded phase cannon blow the top off of something the size of Mt McKinley. That suggests kiloton-level destructive force, at least if you horribly overload it.

This, if anything, makes the phaser more competitive, because it can conceivably do harm to a target out of proportion to the amount of power expended to project the beam.

The point being that you really, really don't know that projectiles work better than phasers in all ways. Or that it would be fully practical to replace the phaser mount with a mass driver of comparable size and expense and get a weapon system of equal or greater effectiveness. If there are serious disadvantages to using projectiles that you haven't thought of, they could easily explain why people don't do that more often.

One advantage I see over a phaser strip instead of a phaser or mass-driver turret is traverse speed. The strips do allow for very good coverage. As a particle accelerator, they suck though. So it might be a trade off between raw kinetic force and the ability to shoot in any direction without having to turn a turret.

It's also non-obvious that the phaser works by accelerating particles at all. If it projects some kind of radiation (electromagnetic or otherwise), then it may well be that there is no need for long acceleration distances. Think about the phased array antennas used on many modern radars.

[Sea Skimmer]

Well yeah I'm not saying they absolutely should remove the warhead, but I was thinking about a tank-fired sabot round which requires no warhead to make a kill.

Ah but that only works because the sabot has very high energy and a fairly high size compared to the target, with only a single internal compartment, and converts some of the tanks own thick armor into damaging internal spall. In the case of DU shells the sabot also catches on fire to help expand the damage path. Also no other ammunition the tank can fire from its gun will be effective at all anymore, leaving little actual choice. Meanwhile high explosive shaped charge ammunition is still used against lightly armored vehicles which will have much less armor spalling, in ordered to improve the damage path and generally produce more well rounded effects. In WW2 meanwhile when tank guns were less powerful relative to the size of the vehicles armor piercing high explosive ammunition was more commonly used then solid shot. This considerable increased the chance of actually destroying a vehicle as opposed to just making a hole in the armor and killing several crewmen.

Trying to contain anti matter in a shell accelerating under forces which might exceed the yield strength of the shell wall material wouldn't be fun meanwhile. It also would make the shell easier to destroy, require much larger guns and ammo and generally be far more expensive anyway. Low average acceleration is much easier to work with, and missiles also give you the option of saving most acceleration for the terminal phase when you need it most to evade defenses and deal with last ditch maneuvering. A missile might cruise with only a fraction of its total delta vee, then, with its now reduced mass suddenly undergo a final burst of acceleration. See the Russian Klub missile for a real life example of this concept in the anti ship role.

Ideally we then make the missile warhead a bomb pumped X-ray laser, or similar directed energy technology, maybe even just a Casba Howitzer, so we don't have to strike the hull and run afoul stuff like reactive armor, just get as close as possible.

It's also non-obvious that the phaser works by accelerating particles at all. If it projects some kind of radiation (electromagnetic or otherwise), then it may well be that there is no need for long acceleration distances. Think about the phased array antennas used on many modern radars.

Its also entirely possible that it accelerates particles, but does so with a racetrack circular setup as in say, CERN, that only shunts into the emitted beam as required. Then you could accelerate slowly but still reach incredibly high velocities. The fact that a ships phaser banks can be 'drained' without the ship loosing power would suggest they've got something going on that involves charging, and aren't employing a solid state laser like direct conversion of electricity into beam energy.

[StarSword]

Its also entirely possible that it accelerates particles, but does so with a racetrack circular setup as in say, CERN, that only shunts into the emitted beam as required. Then you could accelerate slowly but still reach incredibly high velocities. The fact that a ships phaser banks can be 'drained' without the ship loosing power would suggest they've got something going on that involves charging, and aren't employing a solid state laser like direct conversion of electricity into beam energy.

Incidentally this might also rationalize the special effects when a GCS fires its saucer phaser strips. You get a charge moving along the strip from either direction and they fire where the charges meet.

[Simon_Jester]

Ideally we then make the missile warhead a bomb pumped X-ray laser, or similar directed energy technology, maybe even just a Casba Howitzer, so we don't have to strike the hull and run afoul stuff like reactive armor, just get as close as possible.

Though I will say that, despite the opinions of a dear friend of mine, the idea of reactive armor becomes a bad joke for even mildly relativistic weapons- because, again, they're basically a dense particle beam. A particle beam doesn't much care whether the ERA brick it crashes into is a brick or a cloud of vapor; it experiences roughly the same amount of scattering, spalling, and absorption either way.

ERA works because armor penetration relies on physical interactions of solid or fluid matter to work, and having the armor suddenly explode in the penetrator's face disrupts that. There's a lot less to disrupt in the extreme high-velocity limit.

[Sea Skimmer]

I'm thinking more like proximity fused capsules that blow a cloud of deuterium into the path of the projectile and induces a ripple of small fusion explosions to destroy it, then anything like 1980s style ERA bricks on a tank. The point is to gain depth more then anything else, and use the energy of the projectile against itself. If we had anti matter, then we'd just use that in a fully active system.

Making this idea work ought to be about ten billion times easier then mounting large relativistic weapons on a spaceship. Frankly if we have the power and technology to make that work, I strongly suspect we'll be able to make spaceships with the 3D agility, as in engines on all sides, and power margin to evade them all day long anyway. Not to mention the problem of the relativistic weapons damaging themselves when they hit random interseller hydrogen, making it rather unlikely that they could be effectively guided even if the technology existed to do so. I really don't take them seriously as a ship to ship weapon even with a healthy dosage of sci fi. Be good for point defense themselves though.

I do kind of wonder, given a 1 billion G class of acceleration though, if any known material actually could hold together above the molecular scale, if even then. Otherwise its going to have horrible things happen just as it exits the barrel, which takes us back to the idea of a particle accelerator working on the atomic scale for projectiles.

[dragon]

because we don't actually know that projectiles are effective against Federation shields without a warhead.

Actually we do there was the Isokinetic Cannon from voyager It destroyed a target buoy composed of 10 m thick solid monotanium with a chromoelectric forcefield in one shot, coring it cleanly through. So we know kinetic rounds can penetrate forcefields. How those fields stand up to federation shields is a question for debate. But since they went to the trouble of installing the cannon on Voyager would seem to indicated they thought it would be effective against shielded targets.

Plus didn't they make a forcefield from a combadge that deflected a bullet on the holodeck if they could I'm sure the Borg could as well

[Borgholio]

solid monotanium with a chromoelectric forcefield

So, a pure element (mono) with a very colorful electric forcefield? Gotta love that mouthful of technobabble.

Plus didn't they make a forcefield from a combadge that deflected a bullet on the holodeck

I think B'lanna made a forcefield out of a phaser once too. What CAN'T you make a forcefield out of, anyways?

[Simon_Jester]

Bagels.

I'm thinking more like proximity fused capsules that blow a cloud of deuterium into the path of the projectile and induces a ripple of small fusion explosions to destroy it, then anything like 1980s style ERA bricks on a tank. The point is to gain depth more then anything else, and use the energy of the projectile against itself. If we had anti matter, then we'd just use that in a fully active system.

At some point this sort of converges with the concept of CIWS weapons, and arguably a CIWS system would be more effective because the mounts are designed to traverse.

That said, if you have relativistic projectile weapons as a serious threat, then your problem becomes a bit different. At those speeds, even if the projectile breaks up 100 kilometers from your hull it's still in a fairly compact mass when the expanding cloud of plasma hits your ship. Unless of course you shoot back with relativistic shrapnel shell.

Making this idea work ought to be about ten billion times easier then mounting large relativistic weapons on a spaceship. Frankly if we have the power and technology to make that work, I strongly suspect we'll be able to make spaceships with the 3D agility, as in engines on all sides, and power margin to evade them all day long anyway.

Had you decided to stick around in SDNW4, you would have seen me present exactly this.

Not to mention the problem of the relativistic weapons damaging themselves when they hit random interseller hydrogen, making it rather unlikely that they could be effectively guided even if the technology existed to do so. I really don't take them seriously as a ship to ship weapon even with a healthy dosage of sci fi. Be good for point defense themselves though.

I once sat down and mathed out the energy intensity being dumped on the nosecone of a relativistic projectile, in watts per square meter. I'm trying to look up the result... Ah, yes. From an "Honorverse versus Legend of Galactic Heroes" thread a few years back.

Moreover, I repeat that the intensity of radiation a hypothetical Honorverse ship traveling at .9c would encounter is extremely weak compared to the intensity of a weaponized charged-particle beam. Figuring on a (relatively high) density of about five particles per cubic centimeter... hang on.

Point nine c means roughly 2.2 GeV protons, figure on a ship frontal cross-section of, oh, eyeball it at 10000 square meters, that's somewhere in the right general range for a large Honorverse ship...

sweeping a volume of 10000 square meters times 270000 kilometers/second...

is 2.7*10^18 cubic centimeters per second, taking a total power input on the nose of about 3*10^19 GeV/s. Convert to meter-kilogram-second... 4.8 GW across the entire bow of the ship. Which is a quite significant amount of punishment, but nowhere near the kind of energy (let alone the kind of intensity) routinely thrown around in Honorverse or LoGH beam weapons.

Doing a bit of division, I assumed the ship had a frontal cross section of ten thousand square meters, picking up 4.8 GW of radiation flux, so that translates as 480 kW of radiation flux per square meter...

So ignoring any effects from transmutation, neutron spallation, and other problems unique to radiation, the heat transfer to the front of an object moving at 0.9c, due to friction, is roughly 350 times that which we experience from sunlight at the Earth's surface, or more than 40 times that experienced due to sunlight at high noon on Mercury.

Yeah, that's gonna be pretty rough. Honestly, you need either a thick ablative shield, a somewhat less thick ablative shield of magic materials, or a force field of some kind.

I do kind of wonder, given a 1 billion G class of acceleration though, if any known material actually could hold together above the molecular scale, if even then. Otherwise its going to have horrible things happen just as it exits the barrel, which takes us back to the idea of a particle accelerator working on the atomic scale for projectiles.

Pretty much, yes. If you have that level of acceleration, what you really need is a very very uniform application of force- say, some kind of tractor/pressor beam that switches on and applies a uniform force to every particle in the shell, so that the net accelerations are relatively small and limited to the 'fringe effects' of the primary driving force.

The flip side of that, of course, is that like I always say, a plasma cannon is just what happens when you fire a mass driver with homicidal indifference to the projectile's health and welfare.

[Sky Captain]

Pretty much, yes. If you have that level of acceleration, what you really need is a very very uniform application of force- say, some kind of tractor/pressor beam that switches on and applies a uniform force to every particle in the shell, so that the net accelerations are relatively small and limited to the 'fringe effects' of the primary driving force.

In a setting like Honorverse with gravity manipulation tech it may be possible to accelerate projectiles with gravity fields that act uniformly on whole projectile to avoid it breaking apart. IIRC Honoeverse infantry rifles use gravity to accelerate very small bullets to several km/s. However ships don't have any gun type weapons maybe because given the acceleration and relativistic speed capability of gravity drive missiles there is no need to mount cumbersome gun system on a space ship.

[Batman]

The stated MV for infantry pulsers is a mere 2000 mps, though, about two and a half times that of a modern day assault rifle. Hardly the level of acceleration where S_J's concerns come into play.

[Simon_Jester]

In a setting like Honorverse with gravity manipulation tech it may be possible to accelerate projectiles with gravity fields that act uniformly on whole projectile to avoid it breaking apart. IIRC Honoeverse infantry rifles use gravity to accelerate very small bullets to several km/s. However ships don't have any gun type weapons maybe because given the acceleration and relativistic speed capability of gravity drive missiles there is no need to mount cumbersome gun system on a space ship.

The launchers they use for their missiles would make pretty respectable mass drivers in their own right. They can sling a 30-100 ton missile 'out the tubes' with velocity that is (supposedly) significant compared to the massive delta-v of the missile.

Which is... the total delta-v is something like... a hundred thousand g for sixty seconds (I'm rounding here) equals roughly... um... sixty thousand kilometers per second, before MDMs are factored in.

The muzzle velocity of the shipboard mass driver, to even be noticeable on those scales, must be measured in the high hundreds or low thousands of km/s.

I have a sneaking suspicion that taking a hit from a dud Honorverse missile, with no engine or warhead whatsoever, would be a major, nuclear-equivalent event. Actually... yeah, fifty thousand kilograms at, say, 0.005c, would be something like 125 megatons. OUCH.


How did I do that in a hurry?

Tip: a rule of thumb I use for soft-SF calculations: a speed of 0.01c, or 3000 km/s, translates roughly into one kiloton of kinetic energy per kiloton of the impactor. Increasing velocity past this point will cause kinetic energy to scale with the square of the velocity (say, 0.1c -> 10^2 or 100 kilotons per kilogram)

So, 0.01c is 3000 km/s is one kiloton per kilogram. 0.02c is 6000 km/s is four kilotons per kilogram. Et cetera.

That is accurate to, oh, 10-20%. At least until you get up to around 60% of the speed of light and the relativistic correction starts mattering enough to subvert your use of the formula.

[Sky Captain]

I have a sneaking suspicion that taking a hit from a dud Honorverse missile, with no engine or warhead whatsoever, would be a major, nuclear-equivalent event. Actually... yeah, fifty thousand kilograms at, say, 0.005c, would be something like 125 megatons. OUCH.

Yeah, the warhead ads little at that point. At engine burnout at 60 000 km/s kinetic energy would be in gigaton range. I can only rationalize the need for warhead because in Honorverse achieving direct impact is extremely difficult because of point defense and because impeller wedges destroy any matter they contact and it is hard to get precise reading where exactly the ship is located within wedge. So the bomb pumped laser warhead is only way how to reliably score some hits and even then you need a spam of missiles to take out major warship.
Against unprotected stationary targets those missiles would be devastating without any warhead. A single rogue warship probably could pretty much devastate entire planet killing billions with its missile armament if missiles are used as kinetic impactors.

[StarSword]

Against unprotected stationary targets those missiles would be devastating without any warhead. A single rogue warship probably could pretty much devastate entire planet killing billions with its missile armament if missiles are used as kinetic impactors.

As a matter of fact, a few books before the Sollies are revealed to be useless there's a fight near a planet, and the invading CO muses about having to be careful with his targeting because even though he's not aiming at the planet on purpose, a stray shot could still hit the planet and do serious damage. Never mind pissing off the Sollies thanks to the Eridani Edict.

[Simon_Jester]

By the way, if anyone really cares, the error if they use the "one percent c is one kiloton per kilogram" rule of thumb is... hm... OK, it lowballs impactor energy by 7% (since a kiloton is 4.2 TJ, not 4.5), and further lowballs it by an amount equal to the Lorenz factor. The error is (roughly)...

7.5% at 0.1c,
9% at 0.2c,
12% at 0.3c,
16% at 0.4c,
22% at 0.5c,
32% at 0.6c...

and it starts getting rapidly worse from there.