'Clean' nukes and the nature of Honorverse sidewalls

[phongn]

Ok, that you all, this simplifies things for me a great deal

But two questions: why arent modern nukes high-yeld. And, more so, is there a definite mininal size one could squeeze a 300gt nuke into, i.e could one be fit into something the size of a Tomahawk missile?

The radius of destruction is proportional to the cube root of the yield of the device. IOW, to double the destructive radius you'd have to increase the yield by some eight times (2^3), to triple the radius, some 27x (3^3) and so forth. It quickly becomes more efficient to hit a target with many smaller weapons than one huge one.

The large multi-megaton weapons were almost exclusively dedicated for taking out hardened targets. Also, you'd be amazed at how "little" damage they might do; a 1MT airburst over the center of London would "only" take out 10% of its assets (and 20% of its population).

I ask this cause the 'clean' nukes (err...actually, i call them 'atomics' for purely aesthetic purposes) in the story are about the size of a modern cruise missile, but have multi-gigaton yelds.

I'm not quite sure if that's realistically possible short of using antimatter warheads, but it's your story! As long as things are consistant things are fair game.

[18-Till-I-Die]

Ok so heres what i'm thinking:

Atomics are incredably efficient fusion weapons, equal in explosive power to three-hundred gigatons of high explosive, and fueled by a promethium core. Propelled at near-light speeds by a small magnetic 'sail', the hardened neosteel 'beak' punches through the enemy ship's armour, and it drives deep inside before detonating. Though unguided, they are designed to take not of a target's position, and airburst detonate if they overshoot the enemy, to cause at least some damage. These airbursts in large numbers are effective against a ship's shields.

I was figuring the explanation for what shields are can remain a mystery. Most of this is going in the tech bible, and some will be mentioned in some of the story's narration, like the missile's yeld or speed or how it penatrates the ship's hull and such, maybe some other points too.

Any advice?

[Darth Wong]

There's no need for such a large weapon against a vessel which can't even stop the missile from striking and penetrating its hull. A detonation of that size would cause a global environmental havoc if it went off on Earth.

[Spanky The Dolphin]

As I said before, if the description of technologies and their manner of operation isn't important to the actual plot or progression of the story, don't even bother wasting time and effort on such trivia. Most of the time the reader won't even give a shit either way.

[18-Till-I-Die]

I figure most starships have defense weapons (high energy lasers, railguns, counter missiles) and some ships like frigates and destroyers are designed specifically to shoot down fighter craft and torpedoes. Also, these ships are made of neosteel, which is really strong compared to normal steel, and thus it requires a lot of firepower to blow the ship apart. They also use some beam weapons: neutron cannons and 'quantum' bolt weapons mainly, but also huge lasers and such. But these energy weapons are slow firing, despite their increased range, so missiles are more effective as ship-killers.

Also shields are a factor: you have to literally pound them down with brute force, like the Honorverse shields i shamelessly ripped off to create them ( )

[HRogge]

What's about a fusion bomb triggered by some kind of high powered one-shot laser ?

[Elheru Aran]

Well, the big problem is, i was trying to figure out a way that a ship could carry hundreds of thousand sof such misisles (more on the larger ships), as i pictured them being used in thousand-missile volleys at a time.

Are you thinking of something like a WWII rocket ship that the US used to bombard islands in the Pacific before landing? What they did, they launched big barrages of rockets into the air on ballistic trajectories; it was basically rocket artillery. You don't need a whole lot of fancy guidance material in there as long as you have your trajectories calculated right with allowances for atmospheric conditions.

If you want guidance, you have to consider that it makes the rockets much more expensive... it doesn't take much to make a metal tube, fill it with propellant and explosive, attach a nozzle, nose cone, and fins, but when you put electronics into the mix, the price triples (or more). It also cuts down on the amount of explosives in there.

If you want something that's going to cause a lot of destruction, your best bet is kiloton-range nukes; smaller, expensive, but definitely sufficient. 300-gigaton nukes are just plain overkill-- an airburst over an ocean with one of those would literally vaporize a huge amount of ocean, and cause catalysmic environmental/ecological/global destruction. It'd be best suited for a doomsday weapon a la Dr. Strangelove.

My advice? Go with either high-powered conventional or small nukes. Both are plausible enough.

Incidentally, a little background on this story of yours might help... for example, does your society use nuclear weapons on a large scale or what? Is it wealthy enough that it can afford the expense of producing mass numbers of missiles (which, after all, are one-time-use weapons)?

[Elheru Aran]

Okay, I just checked (apparently my post was a bit slow, I missed the bit you inserted about your tech)... when you said "ships" I was thinking water craft. If you're talking spacecraft, then a 300-gt nuke is plausible enough, but it'd be enormous-- even mininaturized, it'd be at least as big as the Tsar Bomba, if not larger. That's one HUGE missile... aside from that, nuclear weapons aren't much use in space unless they've got a good guidance system; after the fireball, all that's left is some radiation that can be sifted out by plain old lead sheeting wound around your ships. The main reason why nukes are so powerful on land is because of the fireball, the blast effect (concussion from air compression), immediate radiation (like what happened at Hiroshima and Nagakasi-- many people there died shortly after from radiation damage), and fallout (the main damage factor, but slower-- a long-term thing).

Like I said, go with high-power conventional or kiloton... if it's space though, make sure that they've got darned good guidance systems!

[Sea Skimmer]

Is there any cocievable headroom for improving fusion bomb efficiency? I know we are limited by reactants, but how much of a modern fusion bomb is just the fusion reactants (since it is concievable I'm told to have a pure fusion bomb).

Nuclear bombs as we know them know are in the 98-99% efficiency range, there's no room for improvement in that respect, and I really doubt a fusion bomb could be any more compact. Dial a yield nukes though, as noted by Arrow Mk84 may be far less efficient depending on the yield selection. If you have the potential to yield 300 kt at near 100% efficiency and only explode with the force of 1 then a lot of nuclear material well be left over, giving you a very dirty bomb amoung other things.

As for the Tomhawk missiles, there actually were Tomhawks equipped with nukes, but they were megaton-range... low-end at that. Gigaton-range weapons were mostly bombs or very large missile warheads like ICBM's.

All that is off the top of my head-- I'm no scientist and can hardly make accurate claims (being merely a lowly freshman in college), but it sounds about right to me. Will gladly accept any corrections...

Well firstly Tomahawk only has a yield of 200 kilotons maximum and we've never seen approached a gigaton range weapon in any form. The largest nuclear weapon ever exploded was Tsar Bomba with a yield of 50-60 megatons. It was designed and originally built to yield 100 megatons but the third stage was replaced with lead before the test, probably so that the Tu-95 used to drop it had a chance in hell of escaping the blast.

Okay, I just checked (apparently my post was a bit slow, I missed the bit you inserted about your tech)... when you said "ships" I was thinking water craft. If you're talking spacecraft, then a 300-gt nuke is plausible enough, but it'd be enormous-- even mininaturized, it'd be at least as big as the Tsar Bomba, if not larger.

It would be far larger, it's jumping up in yield by a factor of 3,000 while that bomb was already highly efficient, it couldn't be significantly miniaturized. The bomb would need numerous additional stages to reach that yield, and every stage is bigger then the last. The weight and physical size would be just massive. Though simply getting such a thing to detonate is probably not feasible.

[Symmetry]

HHverse isnt hard sci-fi by any stretch of the imagination.

Oh, well see, i didnt know that Well i knew the Webber was known to technobable, but it seemed like the sidewalls were possible. Well, does anyone knwo of any strong, non-technobable gravity shields then?

HH is a lot better than most space opera, but its still space opera. At least he gets Newtonian physics right. And no, there aren't any such things as strong, non-technobable gravity shields, or any other sort of non-material shields. Magnetically contained plasma is your best bet if you want realism.

[The Nomad]

How strong would a plasma shield be? Could it stand up to multi-gigaton weaponry, for example? And what would be the simplest, explanation?

A plasma shield could use abrasion to damage incoming missiles ( eventually triggering them or damaging their sensor/guidance apparatus ), and scatter EM radiation beams. But AFAIK it would be worth shit against large scale nuclear detonations ( opaque clouds of particles would do better, and anyway the EM pulse would fuck off the containment field ), and sheer KE.

Might as well use a wall of exotic matter, or a kind of LDA-shield from I-War. Or some tough armor, like Xeelee construction material...

[harbringer]

Why not just use a fissionable element that is currently unknown it won't be real hard science fiction but it could solve your problems. Perhaps something discovered by a colony or something. As for shielding I doubt even the US government can make magnetic shielding work and we more or less understand magnetism. To stop warheads borrow something from HH and have lasers blind or kill the missiles at range. From memory a carbon dioxide laser could do it if you had enough power (it is however invisible). Use of decoys and electronic counter (and counter counter) measures would be important in that case.