Technical questions

Hi, I have been mulling over several questions regarding the Honorverse physics and technology

Antigravity. When your air car/shuttle/belt or whatever switches on its antigravity, if near the equator why doesn't it just head off on a tangent at a great rate of speed? Centripetal force and all that?

When someone like Frontier Fleet wants to do surface bombardment they use KEWs. Fair enough, but why not use their main energy broadside? We are told that they can demolish small moons or large asteroids. An energy bloom in the atmosphere? That would seem to add to the effect.

What is the mechanism to harvest the energy in a fusion bottle? Can't be as of now, with a boiler and steam turbines attached to a generator.

I do accept that the concept of the extremely high energy involved in a high C missile has been accepted in later books, but why bother with a warhead if seeking a contact explosion? Considering the free energy imparted, could close to C missiles get even higher with massive ablative armor?

Why don't hand and shoulder weapons have extreme recoil, considering the energy they impart to their projectiles?

Disclaimer. I'm an extreme Weber fan, and in awe of how well he framed his series from a stand alone novel over 20 years ago. But eternally curious.

Daryl wrote:When someone like Frontier Fleet wants to do surface bombardment they use KEWs. Fair enough, but why not use their main energy broadside? We are told that they can demolish small moons or large asteroids. An energy bloom in the atmosphere? That would seem to add to the effect.

Hmm, I guess it's about dissipation and losing coherence of any kind of radiation in the atmosphere.
If you are firing in the vacuum there is nearly no "particle induced" physical effect to the beams but in the atmosphere, the density will increase with every meter towards the ground and therefore the effect of every molecule.

And a seconed effect could be, that nobody want to ignite
the oxygen in the atmosphere.

But in the end I guess, it sounds much better to have a kinetic projectile.

Daryl wrote:Hi, I have been mulling over several questions regarding the Honorverse physics and technology

Antigravity. When your air car/shuttle/belt or whatever switches on its antigravity, if near the equator why doesn't it just head off on a tangent at a great rate of speed? Centripetal force and all that?

Coriolis force is never mentioned, nor centripedal forces. supercomputers on belts making counteracting forces? don't know.

When someone like Frontier Fleet wants to do surface bombardment they use KEWs. Fair enough, but why not use their main energy broadside? We are told that they can demolish small moons or large asteroids. An energy bloom in the atmosphere? That would seem to add to the effect.

Energy weapons can be used, they are just messier (as you mention) - In fact, there are energy weapons emplacements on the Landing Palace grounds to attack orbital targets (works both ways). KEWs are just... cleaner... you can easily dial them up or down to achieve the results needed. KEW canisters can also be seeded as satellites, so you get global orbital coverage and quicker responses than once every 90ish minutes.

What is the mechanism to harvest the energy in a fusion bottle? Can't be as of now, with a boiler and steam turbines attached to a generator.

Plasma Magneto Hydrodynamics... but David handles it just like it's a live steam system with accumulators (super capacitors) and live steam piping systems (Plasma conduits)

I do accept that the concept of the extremely high energy involved in a high C missile has been accepted in later books, but why bother with a warhead if seeking a contact explosion? Considering the free energy imparted, could close to c missiles get even higher with massive ablative armor?

The original system David set up, missiles in combat never got close to c relative to the firing ship, and ships usually did not have a high relative closing speed against each other. (ships rarly got above .3c on a direct vector from the hyperlimit to a habitable planet, and most battles happened near a planet, so fleets needed to decell to a low speed if they wanted to contest the planet.) so Missiles with short ranges needed warheads to do significant damage.

Only after 3 and 4 drive missiles gave missiles ridiculous ranges (remember, Honor paraded Missiles through Tourville's formation from 150Km away - that's the roughly the distance between Earth and Mars at their shortest approach) could a moving ship be targeted by a missile who built up such momentum.

So in the original foundation of the Honorverse, a powered, controlled missile didn't have as much kinetic energy - in most cases. And for the cases where the missile did build up enough energy, "sidewalls" can swallow any big kinetic strikes. <handwave>... it's the reason why there are no capital kinetic weapons on ships.

Why don't hand and shoulder weapons have extreme recoil, considering the energy they impart to their projectiles?

From Jayne's, grav powered weaponry also have a countergrav recoil system powered by the same battery.

Disclaimer. I'm an extreme Weber fan, and in awe of how well he framed his series from a stand alone novel over 20 years ago. But eternally curious.[/quote]

Theemile wrote:The original system David set up, missiles in combat never got close to c relative to the firing ship, and ships usually did not have a high relative closing speed against each other. (ships rarly got above .3c on a direct vector from the hyperlimit to a habitable planet, and most battles happened near a planet, so fleets needed to decell to a low speed if they wanted to contest the planet.) so Missiles with short ranges needed warheads to do significant damage.

On a direct vector from the hyperlimit to a planet I'd go so far as to say ships never got anywhere near 0.3c. The highest accelerating ship we know of from period of the early series is Haven's 38,000 ton Facteur-class dispatch boat (IIRC from Jaynes).

At its military maximum (80%) acceleration it could do 428.56 G.
Giving it the best benefit of the doubt; the very highest velocity you can retain from the hyper translation out of the Alpha bands is 8% of 60% of c; or 14,390 KPS (or about 0.048 C).

Given that base velocity it would take a Facteur 17,988 seconds to reach 0.3c; during which it would cover 939,022,360 km (52.2 lightminutes. Most planets are within 5-10 lightminutes of the hyper limits; and for most stars the hyperlimit radius is only twenty-odd lightminutes across - after nearly 5 hours of hard accelerating the DB has not only blown way past the planet, and the star, but is nearly flow out the far side of the hyperlimit!

And most ships accelerate noticeably slower, and very few use approaches that optimize for maximum residual velocity upon hyper exit -- which require you take the significant amount of time to work back up to 0.6c again after dropping down into the Alpha bands.

Ships back then only got up to 0.3c in normal space under some special circumstances - the most common probably being a high speed passage from the hyper limit to a wormhole terminus through the RZ (where you can't safely hyper) -- that's a long enough trip many (most?) warships could hit a turnover velocity in excess of 0.3c.

Daryl wrote:I do accept that the concept of the extremely high energy involved in a high C missile has been accepted in later books, but why bother with a warhead if seeking a contact explosion? Considering the free energy imparted, could close to C missiles get even higher with massive ablative armor?

Seems like he gave them warheads because he gave warship perfect and near-perfect defenses against kinetic missile strikes.

Roll the ship and your wedge will basically ignore anything that isn't another wedge of at least roughly comparable power. And even sidewalls will stop any missile whose sidewall penetrators don't work perfectly (those are said to basically use the missile's wedge to 'tear' a temporary hole in the sidewall for the missile to fly through). And the wedge and sidewalls also obscure where the ship is, so good luck lining up on it before penetration. And after penetration there isn't time to adjust your vector.


So, even if you could punch a 0.25c missile through the sidewall approximately 70% of the volume behind them is just empty space; the ship is a pretty small needle in a huge fogbank. Oh, and you've hit the far sidewall before the missile can react - at 0.25 c the missile crosses that distance in about 3/10,000ths of a second; during which its acceleration (if its wedge somehow survives being used as a sidewall penetrator) can adjust its trajectory by about 2 centimeters.

So to overcome that near-perfect defense against kinetic kills you use the missile velocity to help get past the anti-missile defenses and then you use the warhead to cover a larger area and/or shoot 'sideways' as you overfly the target.

And, somehow, the sidewalls that David granted near perfect immunity to kinetic impacts he made weak (in comparison) to directed energy weapons -- even though the photons or charged particles of those carry a tiny fraction of the raw energy represented by the missile's mass and velocity. <shrug>



Oh, and if we go back to the earlier Honorverse, before sidewalls were invented, the missiles were vastly slower - though still kinetically dangerous. But that was generally irrelevant as their wedges would tear apart pretty much anything they touched (other than a wedge of a ship or CM) - and their wedges projected probably at least half a km ahead and at least a km to the sides of the missile body; so a target would be shredded by the missile wedge before any kinetic impact could occur (and could still be shredded by a missile that would have failed to quite connect with the target) It was the wedge of the impeller missile that was the real shipkiller of that era.

Kinetic impact would only come into play if trying to hit something so far away the wedge would burn out before the missile reached there. But you'd need an especially oblivious, or unlucky, ship for it to fail to dodge your missile after wedge burnout.

The first bunch of books (5 iirc) were written as a package and submitted together. So there are some ofd things that go on in them that fan feedback helped fix later.

Daryl wrote:Antigravity. When your air car/shuttle/belt or whatever switches on its antigravity, if near the equator why doesn't it just head off on a tangent at a great rate of speed? Centripetal force and all that?

Because we know people don't fly off on a tangent, the countergravity system isn't just nullifying the force of gravity, but instead creates a repulsive force that causes the object to float. We know from the Star Kingdom series that people on Sphinx but not born on Sphinx carried countegrav belts that helped them alleviate their weights, in case of a fall. Similarly, Stephanie and Karl in their roles as Forest Rangers did use those same countergrav belts to "climb" up trees by floating up. It was just a setting. Come to think of it, it's very similar to buoyancy

This means the planet's gravity is still in effect, but counteracted a little. In turn, it means you're still pulled down and therefore have a velocity component that is centripetal, thus keeping you above the same spot on the planet while said planet rotates. Or at least roughly... there may be a Coriolis or Coriolis-like effect that you move Eastwards or Westwards as you go up or down, but those effects are probably negligible for the scenes we've seen with people and belts, and cars would just adjust for it. This may actually be the reason why you can go up: you nullify gravity a little in such a way that the surface of the planet turning underneath you is actually moving away from you while your motion (as seen from an outside observer) is closer to linear.

Also, as far as I (don't) understand it, the Math for the 4-D tensors in a gravitational field in General Relativity is a little more complex. There was a Veritasium video on this.

Thanks all, I do appreciate the feedback. One clarifier, in regard to the inherent in light speed operations, I never considered ships. However multistage missiles do crowd C where E=MC2 gets interesting above 0.9C.
As some wag once postulated, it isn't true that in SiFi no object can achieve exactly C. At C, mass is infinite, so one can, one per universe.

Daryl wrote:Thanks all, I do appreciate the feedback. One clarifier, in regard to the inherent in light speed operations, I never considered ships. However multistage missiles do crowd C where E=MC2 gets interesting above 0.9C.
As some wag once postulated, it isn't true that in SiFi no object can achieve exactly C. At C, mass is infinite, so one can, one per universe.

So as long as the universe exists, no other object can be that fast?

Jonathan_S wrote:And, somehow, the sidewalls that David granted near perfect immunity to kinetic impacts he made weak (in comparison) to directed energy weapons -- even though the photons or charged particles of those carry a tiny fraction of the raw energy represented by the missile's mass and velocity. <shrug>

It can be inferred from textev that kinetic energy from an impact on the wedge or the sidewall is transferred to the ship (ship shaking from impacts, see textev from the Yawata-strike where the tugs are using their wedges on debris). My guess is that the energy is dumped into the sump with some bleedthrough since no system is 100% efficient.