Antigravity nation vs teleportation nation (RAR)

[vengence]

Didn't we just go through a round of crude calculations that showed no "air cargo ships" would exist?

Even if they did, repurposing them into "crude bombers", yet with the capability to cripple infrastructure is way more difficult than you're suggesting. For one, you'd need to produce all the weapons to arm them, install bombsights and train the crews in doing bomb runs - and run into the fact that "peacetime readiness" does not mean "complete lack of any defences whatsoever". The fact the US has a rather lousy air defence network right now doesn't mean Russia could cripple them with a sneak attack using converted passenger liners.

I think we determined that the "million ton"(over exaggeration for anyone who wants to be nitpicky) skylords accelerating to mach 3 was improbable, but a quick look at current transport aircraft with current technology we can accelerate 500 ton planes to 80% mac one as it is.

most likely the "Skylord" class vessel will be a slow semi mobile aircraft carrier, or resupply tankers for vessels and outposts operating in the air. these would be more support vessels as opposed to forward assault vessels, and they would likely move at speeds closer to traditional naval vessels(as those are likely the mass sizes we would be looking at) likely no greater than 100km/h.

That's not how orbits work. Even if antigrav units could proper you all the way to an orbital ALTITUDE, you'd still need to give the payload all the necessary orbital VELOCITY, which would require traditional boosters of only slightly less size than what you'd normally need. You save quite a bit of launch mass on two things: one, aerodynamic drag in the lower atmosphere and two, the fact you can use one type of engine optimized for low-pressure operation (normally rockets use at least two types of engines, because different fuels and configurations work with varying efficiency in and out of atmosphere)

But it's not something that can make a crushing difference, especially if teleporterstanis can use them to replace a space elevator. Then the antigravburgians are down to trying to deny space to the enemy Which might work for LEO (thus, no spy satellites), not so much for GEO. Especially if the teleportstanis get a chance to set up killsats to kill the delivery mechanisms before they can insert the debris into dangerous trajectories.

My idea was not to raise an object to orbital altitudes but, use the anti gravity units to rapidly ACCELERATE the payloads, as close to escape velocity as it can until it hits its altitude cut off at which point the booster rockets would ignite taking it to orbit, this way the cost to get the payload to escape velocity would be largely negated.

Also the ability to build a station big enough to house a teleporter(at least the really big ones and any pad big enough to move anything greater than a person or similar size ) would require an almost complete dominance in the field, or to build it in a time of relative peace(in which there would likely be treaties to be signed that would likely prevent building space weapons), because the antigravburgians would likely be building stations and killsats on their own and likely be trying to disrupt said construction efforts.

[Sky Captain]

Didn't we just go through a round of crude calculations that showed no "air cargo ships" would exist?

We argued about feasibility of flying multi million ton battleships, but air freighters definately should be possible and economical. Remember that big pre WWII era zeppelins cruised at ~140 km/h only with few MW of power. With anti grav keeping the ship in the air there is no reason why roughly zeppelin sized and shaped freighter couldn't carry payloads comparable to ocean going bulk carriers. A typical real world zeppelin sized bulk carrier may carry 50 000 tons and travel 30 km/h using ~20 - 30 MW. Now if you could go 5 times as fast with only 5 MW of engine power (likely two diesel engines turning large propellers) it would be very energy efficient way to ship freight. Not to mention the fact that basically anything could be shipped anywhere point to point.

Even if they did, repurposing them into "crude bombers", yet with the capability to cripple infrastructure is way more difficult than you're suggesting. For one, you'd need to produce all the weapons to arm them, install bombsights and train the crews in doing bomb runs - and run into the fact that "peacetime readiness" does not mean "complete lack of any defences whatsoever". The fact the US has a rather lousy air defence network right now doesn't mean Russia could cripple them with a sneak attack using converted passenger liners.

Yeah, but it is a better starting position than teleport guys who likely would have only few cargo aircraft for firefighting and to transport occasional cargo that is too massive to teleport and cannot be broken down into smaller pieces and also lack significant number of trained pilots.
IIRC in Vietnam war US sometimes did use cargo planes to drop bombs that were too large to fit into B52 although accuracy probably sucked.

[Terralthra]

Didn't we just go through a round of crude calculations that showed no "air cargo ships" would exist?

We argued about feasibility of flying multi million ton battleships, but air freighters definately should be possible and economical. Remember that big pre WWII era zeppelins cruised at ~140 km/h only with few MW of power. With anti grav keeping the ship in the air there is no reason why roughly zeppelin sized and shaped freighter couldn't carry payloads comparable to ocean going bulk carriers. A typical real world zeppelin sized bulk carrier may carry 50 000 tons and travel 30 km/h using ~20 - 30 MW. Now if you could go 5 times as fast with only 5 MW of engine power (likely two diesel engines turning large propellers) it would be very energy efficient way to ship freight. Not to mention the fact that basically anything could be shipped anywhere point to point.

Are you daft? Could you care to explain why a sky bulk carrier's propulsion system is 25 times more mechanically efficient than a real-world bulk carrier?

[madd0ct0r]

because a zeppelin was a big bag of gas that would tear itself apart if you accelerated too fast?

[Terralthra]

because a zeppelin was a big bag of gas that would tear itself apart if you accelerated too fast?

That's not what I'm saying. If a sea bulk carrier takes 25 MW to go 30 km/h, how do you justify a sky bulk carrier going five times as fast using 1/5th the power (5 MW vs. 25 MW)? That's simply an asspull of epic proportions. Modern semi-rigid airships like the Zeppelin NT can cruise at 70 mph on .5 MW, but it can carry a grand total of 1.9 tonnes of cargo, with a max weight (ship and cargo) of 10 tonnes. If you think 10 times the engine output will power 25,000 times the cargo capacity, great, but I'd like to see some sort of justification for that kind of speculation.

[madd0ct0r]

of course it would. It'd just take longer to accelerate. Same drag, same power = same top speed.

A SEA bulk carrier suffers massively higher drag effects due to having to push it's way through a much denser and thicker fluid - the sea.

[Terralthra]

A disadvantage which is balanced by the fact that being of greater density, water is a much better reaction mass than air.

Edit: redundancy.

[madd0ct0r]

well yes, a ships propeller will be very inefficient operating in open air.

your point being?

[madd0ct0r]

ghetto EDIT: Ok, your point is pretty obvious - the effciency gain from not going through water, is exactly the same as the effcieny loss from not having water as a reaction mass.

this is obviously and trivially wrong. Pick two liquids with the same densities and different viscosities and think about it.

[Beowulf]

Terralthra: Air resistance doesn't depend on mass. It depends on coefficient of drag, air density, and frontal area. Therefore, the power to maintain velocity depends only on coefficient of drag, air density, and frontal area. You failed physics, didn't you?

As for anti-gravity giving a slingshot to rocket payloads: we have no clue what acceleration in the vertical axis that anti-gravity is capable of. It could be hundreds of Gs... or it could be enough only to gain a couple feet in a minute.

[Terralthra]

Terralthra: Air resistance doesn't depend on mass. It depends on coefficient of drag, air density, and frontal area. Therefore, the power to maintain velocity depends only on coefficient of drag, air density, and frontal area. You failed physics, didn't you?

No. Air resistance doesn't depend on mass, but inertia does. If it takes a year and thirty tons of fuel to get moving at cruising speed, your cargo ship sucks.

[PeZook]

More to the point, even if it CAN reach 140 kmph, it will not be a bomber: it will just be a target.

All you'll accomplish will be crippling your own economy for no gain at all, because WWII era fighters and 60s era SAMs would be able to destroy an arbitrary number of them.

[PeZook]

We argued about feasibility of flying multi million ton battleships, but air freighters definately should be possible and economical. Remember that big pre WWII era zeppelins cruised at ~140 km/h only with few MW of power. With anti grav keeping the ship in the air there is no reason why roughly zeppelin sized and shaped freighter couldn't carry payloads comparable to ocean going bulk carriers. A typical real world zeppelin sized bulk carrier may carry 50 000 tons and travel 30 km/h using ~20 - 30 MW. Now if you could go 5 times as fast with only 5 MW of engine power (likely two diesel engines turning large propellers) it would be very energy efficient way to ship freight. Not to mention the fact that basically anything could be shipped anywhere point to point.

Oh, ha ha

The most powerful prop engine ever devised was the NK-12M which had 11 MW of power. Four of those were enough to drive a 185 ton Tu-95 at 650 kmph.

You are talking about using ONE EIGHT of that power to drive a ship weighing TWO HUNDRED TIMES MORE? You're not going to save much on drag, because a 50 000 ton freighter would be nowhere near as aerodynamic.

Yeah, but it is a better starting position than teleport guys who likely would have only few cargo aircraft for firefighting and to transport occasional cargo that is too massive to teleport and cannot be broken down into smaller pieces and also lack significant number of trained pilots.
IIRC in Vietnam war US sometimes did use cargo planes to drop bombs that were too large to fit into B52 although accuracy probably sucked.

They used C-130s to drop Daisy Cutters, but C-130s are not considered bombers because a WWII era fighter will easily destroy one.

That's why ponderously floating your 50 000 tonne bombers into enemy airspace is a bad idea ; Teleport guys might not have a lot of civilians aviation, but they will have fighters. You will simply NOT achieve surprise and penetrate deep enough to cripple their infrastructure.

[vengence]

While giant ships do not work as bombers they can work as forward mobile assault platforms, or aircraft carriers in the sky. Plus some research into anti missile defense yields weapon systems that utilise some thing like coil anti missile systems. And no mirrors/reflective surfaces will not stop them.

[PeZook]

Yeah, too bad that the "aircraft carriers in the sky" would still require huge amounts of thrust. You want your 50k ton ship to be able to reach 30 knots in, say, ten minutes?

That's 0.025 m/s^2, so total thrust required is 1.25 MN. A rocket engine with such power (you'd need a rocket to go so slow at 22 km) consumes about 350kg of fuel per second or so, so accelerating over 10 minutes will eat up 210 tonnes of fuel.

And of course it will still suffer all the issues of naval vessels. Oooh, it can have lasers?

Too bad it will need more of them than any naval vessel - because it has to cover a much wider firing arc. Otherwise 60s era SAMs can hit it and start fires. But at a certain point, you will run into issues with power generation, consumables etc - just like any other ship, the resources aboard are llimited and have to be balanced between defense, offense, sensors, etc.

Except it floats in the air, so radars hundreds of km away can see it, and vector interceptors to shoot it down, unlike a naval aircraft carrier which is protected by the horizon. A carrier prefers never to be discovered, because it's such a high value target that the enemy can literally shoot hundreds of missiles at it and still come out ahead if only one gets through. A Harpoon costs 1.5 million, a carrier - over a billion.

BTW, I checked the Hindenburg's specifications: it weighed 212 tonnes and used 3.57 MW of power (diesel engines, too), so the idea that a ship weighing 50 000 tonnes could fly using 5 MW is totally absurd. Well, it COULD but it'd need propellers of truly absurd size...

[khursed]

Yeah, too bad that the "aircraft carriers in the sky" would still require huge amounts of thrust. You want your 50k ton ship to be able to reach 30 knots in, say, ten minutes?

That's 0.025 m/s^2, so total thrust required is 1.25 MN. A rocket engine with such power (you'd need a rocket to go so slow at 22 km) consumes about 350kg of fuel per second or so, so accelerating over 10 minutes will eat up 210 tonnes of fuel.

And of course it will still suffer all the issues of naval vessels. Oooh, it can have lasers?

Too bad it will need more of them than any naval vessel - because it has to cover a much wider firing arc. Otherwise 60s era SAMs can hit it and start fires. But at a certain point, you will run into issues with power generation, consumables etc - just like any other ship, the resources aboard are llimited and have to be balanced between defense, offense, sensors, etc.

Except it floats in the air, so radars hundreds of km away can see it, and vector interceptors to shoot it down, unlike a naval aircraft carrier which is protected by the horizon. A carrier prefers never to be discovered, because it's such a high value target that the enemy can literally shoot hundreds of missiles at it and still come out ahead if only one gets through. A Harpoon costs 1.5 million, a carrier - over a billion.

BTW, I checked the Hindenburg's specifications: it weighed 212 tonnes and used 3.57 MW of power (diesel engines, too), so the idea that a ship weighing 50 000 tonnes could fly using 5 MW is totally absurd. Well, it COULD but it'd need propellers of truly absurd size...

The thing that irks me, is that if the anti-grav works on the principle of negating the mass of the material the engine is attached to, then you do not have to force 12 million metric tons of steel forward, you have the equivalent of a volume of matter that fits in the same envelope you have for your ship that can float at that altitude. So your engine efficiency and power to weight ratio just got fantastically better.

Also, the main problems of tanks, has always been the need to be able to ford rivers, and cross on existing bridge and the problem of having armor that cripples your speed. If you build huge tanks, with awesome armor, and float them over rivers, you just got a huge boost over anything the enemy can field, since they are basically floating on the air, then you can actually give them decent speed with a jet engine. Since you can now have A very big floating tank, armor it so it's impervious to any machine guns up to 20mm. Then build it big enough to have room for 2 CWIS, equip it with a GAU8-A, carry 30-40 thousand rounds, for all weapon system, and watch that thing mow down stuff like there is no tomorrow. Carry enough fuel for say a thousand mile of range, and you've got some pretty evil war machines. Build a few really well armored one to take on the teleporter nation's bunker, and they might just be fucked trying to stop you.

It's one thing to have teleporter station, however something tells me that it would be very cost prohibitive to have bunkers with teleporter at every 4-500meter of your whole border to prevent the anti-grav nation from storming your border and over running your defenses.

I think the whole approach of flying at 22 km has made people forget that the simplest idea sometime is easier to put in motion.

I think a very mobile force, with a bunch of extremely heavy floating tanks, would be able to conquer the teleporter nation given some thought. Because the main problem the teleporting nation has, is that it's not as mobile as the enemy. My main idea relies on the trick, that once your anti-grav engine is on, you basically negated the weight of your vehicle, thus a strong wind would be able to move it. Think giant balloons, made of thick steel

So, if the anti-grav does work by negating the weight, then you can build some seriously evil flying machines. All bets are off. From floating super tanks, to battleship skylords.

[Beowulf]

There is no reason to believe that anti-gravity actually negates mass, as opposed to negating weight, either by reducing the weight of the object as a whole (including the objects inside, like people), or by being a brick that tends to resist work caused by gravity up to 22km. Negating mass is actually probably the most problematical idea physically, as you couldn't move at all. You have no mass to cause a reaction with. No reaction mass means no action.

[Purple]

But if the field ignores what ever is inside, and the body has no mass can't a guy just stick a paddle out and propel it to a billion km/h (figuratively)?

[Terralthra]

I interpreted the OP's description of the antigravity device (that it only makes controlling altitude easy, but does nothing for other motion) as meaning it negates gravitational attraction, but does not reduce mass.

[Zor]

I interpreted the OP's description of the antigravity device (that it only makes controlling altitude easy, but does nothing for other motion) as meaning it negates gravitational attraction, but does not reduce mass.

Correct.

Zor

[Beowulf]

I do believe that air cargo ships would be feasible. A ship around the size of the Hindenburg ( about 200k m^3) would probably mass around 50ktons laden. You could build it so that the bottom is essentially solid, and designed for aerodynamics, and top cylindrical section is lightweight fairings, so you end up with a giant cargo hold in the center that you could fill with containers. Pop off the fairings when landed, and use fixed cranes to onload and offload cargo, like on modern container ships. Yeah, it might take a while to build up speed, but you can get a whole lot more efficient with props than with rocket motors, and you don't need rockets to operate at 22km. You can use giant ass props. Boeing's Phantom Eye is probably the highest flying prop plane I've heard of, and it's supposed to manage 65kft. Not quite up to the same height as an antigrav airship, but there's probably reasons other than propulsion for that. Like the fact that 65kft is already above the tropopause, and so you don't need to be higher to avoid weather. You could use thicker air at lower altitudes to increase the propeller efficiency and so be able to accelerate a bit faster. You could have massive ground tugs to help kick it up to speed.

That said, I believe that using the same sort of design for a warship is a losing proposition. It'd be nearly completely unmaneuverable, slow to accelerate or decelerate, and far to vulnerable to such tactics as suborbital kinetic strikes.

Evil idea for anti-airship warhead: penetrator warhead with teleporter inside. After the warhead hits, it starts spewing strong oxidizers (ClF5, IRFNA, LOX, etc), for a while before it ignites the whole shebang. Disadvantage for fighting fires when you're airborne is that you can't just pump seawater onboard to help cool the compartments down. It's also alot harder to fight fires that are fed with oxidizers, because you can't remove the oxidizers from the area, and the fuel is going to be the steel the ship is made from. You're pretty much just stuck waiting for it to burn out.

Zor: does the antigravity actually negate gravity for the object (rendering all objects inside to be in freefall), or is it like a box you strap the rest of the ship to, and it provides a force counter to gravity. The personal lift harness tends to imply the latter to me.

[Sea Skimmer]

Yeah, too bad that the "aircraft carriers in the sky" would still require huge amounts of thrust. You want your 50k ton ship to be able to reach 30 knots in, say, ten minutes?

That's 0.025 m/s^2, so total thrust required is 1.25 MN. A rocket engine with such power (you'd need a rocket to go so slow at 22 km)

No you don't, that's the most nonsensical thing you could say. Rockets suck at low speeds. The NASA Pathfinder UAV reached over 29km while going only 40kph using propellers. Jet engines meanwhile you might notice, work for takeoff from zero airspeed.

And of course it will still suffer all the issues of naval vessels. Oooh, it can have lasers?

Too bad it will need more of them than any naval vessel - because it has to cover a much wider firing arc.

Actually it needs less because it can see a incoming target coming much further away, and can exploit very thin air to make its laser beams far more effective, that was you know the whole point of the US airborne laser program. A laser at each end of a flying ship could provide complete coverage which is no different then what a surface warship is going to need as a minimal.

Otherwise 60s era SAMs can hit it and start fires. But at a certain point, you will run into issues with power generation, consumables etc - just like any other ship, the resources aboard are llimited and have to be balanced between defense, offense, sensors, etc.

A 1960s SSM can blow up a warship too, what's your point?

Except it floats in the air, so radars hundreds of km away can see it, and vector interceptors to shoot it down, unlike a naval aircraft carrier which is protected by the horizon.

Yeah totally a huge problem, because its not like people look for aircraft carriers with radar on aircraft in the first place that can see hundreds of kilometers away right? Did you think about this at all. Meanwhile flying warship can also go over land, and doesn't have its own sensors limited by line of sight either. You notice how the most important plane on a modern carrier deck is its airborne early warning plane? Meanwhile since the flying ship is flying so high, any weapon it launches automatically has much greater range then a similar weapon fired from sea level.

A carrier prefers never to be discovered, because it's such a high value target that the enemy can literally shoot hundreds of missiles at it and still come out ahead if only one gets through. A Harpoon costs 1.5 million, a carrier - over a billion.

I love when people just assume its no problem at all to fire hundreds of missiles at something. Kind of ignores the whole problem of coordination, having launch platforms and a few other factors. Meanwhile a missile that can climb to 22km ceiling at a significant range is a lot more expensive then an subsonic missile that only has to fly at sea level. It needs a much bigger engine, better guidance, better flight controls and a lot more fuel all of which turn into a much larger weapon.

BTW, I checked the Hindenburg's specifications: it weighed 212 tonnes and used 3.57 MW of power (diesel engines, too), so the idea that a ship weighing 50 000 tonnes could fly using 5 MW is totally absurd. Well, it COULD but it'd need propellers of truly absurd size...

Weight only matters for acceleration and a flying ship isn't going to slow down much, no reason it should since it could refuel underway. Drag area and the coefficient of drag are what matter. Since a warship is going to be a lot longer then it is wide or tall its unlikely to have a radically different drag area. Put on a couple jet engines and it will move fine. You might notice modern warships are powered by gas turbines built out of aircraft jet engines in the first place. Propfans are a pretty likely choice for propulsion, though I ducted propulsion isn't unlikely.

[Sea Skimmer]

That said, I believe that using the same sort of design for a warship is a losing proposition. It'd be nearly completely unmaneuverable, slow to accelerate or decelerate, and far to vulnerable to such tactics as suborbital kinetic strikes.

How easily do you really expect anyone to make a suborbital kinetic weapon that can hit a target that moves in 3D at high speed? Turning is kind of easy if you have 90 degree thrust vectoring on the main engines and put some ducted thrusters across the bow. Airships themselves were pretty damn agile for the size and they had nothing like the flight controls that would become possible with modern technology, anti gravity and such a high weight budget. Its not like the thing has to make banked turns here. deceleration isn't a very big idea, air breaks ect... work, accelerating would only matter if you had to slow down which I don't see happening much on a combat mission. Just send up tankers to keep refueling and rearming.

I kind of favor teleporters anyway, but not because a giant flying warship wouldn't be a giant exercise in raping conventional forces.

[Zor]

Zor: does the antigravity actually negate gravity for the object (rendering all objects inside to be in freefall), or is it like a box you strap the rest of the ship to, and it provides a force counter to gravity. The personal lift harness tends to imply the latter to me.

The latter.

Zor

[PeZook]

No you don't, that's the most nonsensical thing you could say. Rockets suck at low speeds. The NASA Pathfinder UAV reached over 29km while going only 40kph using propellers. Jet engines meanwhile you might notice, work for takeoff from zero airspeed.

They work from zero airspeed in the thick air at lower altitudes. Isn't the air at 22km so thin that you have to move above a certain airspeed to compress and heat it up for use in a jet engine?

The Pathfinder is hardly applicable, since it used solar-powered electric engines to drive its propellers. I suppose you could try and spam the flying ship with a massive amount of engine pods, but if you want to burn any sort of fuel the thin air is still going to be a problem, as will its sheer mass.

Actually it needs less because it can see a incoming target coming much further away, and can exploit very thin air to make its laser beams far more effective, that was you know the whole point of the US airborne laser program. A laser at each end of a flying ship could provide complete coverage which is no different then what a surface warship is going to need as a minimal.

Hmm. Good point.

A 1960s SSM can blow up a warship too, what's your point?

Well, with complete coverage with just two laser sets I don't really have one

Yeah totally a huge problem, because its not like people look for aircraft carriers with radar on aircraft in the first place that can see hundreds of kilometers away right? Did you think about this at all. Meanwhile flying warship can also go over land, and doesn't have its own sensors limited by line of sight either. You notice how the most important plane on a modern carrier deck is its airborne early warning plane? Meanwhile since the flying ship is flying so high, any weapon it launches automatically has much greater range then a similar weapon fired from sea level.

My point is that a huge floating carrier doesn't need to be located using airborne early warning, but could be seen with most groundside radars, too.

I love when people just assume its no problem at all to fire hundreds of missiles at something. Kind of ignores the whole problem of coordination, having launch platforms and a few other factors. Meanwhile a missile that can climb to 22km ceiling at a significant range is a lot more expensive then an subsonic missile that only has to fly at sea level. It needs a much bigger engine, better guidance, better flight controls and a lot more fuel all of which turn into a much larger weapon.

It's a problem if you don't have appropriate numbers and sizes of launch platforms, but the teleporter nation could exploit its tech to brute-force very large high-ceiling interceptors with long loiter times.

Weight only matters for acceleration and a flying ship isn't going to slow down much, no reason it should since it could refuel underway. Drag area and the coefficient of drag are what matter. Since a warship is going to be a lot longer then it is wide or tall its unlikely to have a radically different drag area. Put on a couple jet engines and it will move fine. You might notice modern warships are powered by gas turbines built out of aircraft jet engines in the first place. Propfans are a pretty likely choice for propulsion, though I ducted propulsion isn't unlikely.

Inertia also matters for turning, and while you might not want to slow down a whole lot, you will probably want to be able to accomplish course changes in timescales shorter than a geological age. This is where water helps a lot, with thin air to push against you'll need to brute force your turns.