Human Superiority (again)

[Demarquis]

The Loroi and most of the other major combatants use taimat-powered "Floater" drives. Taimat (also known as "Type A" fuel) is an artificially-produced form of exotic matter with similar properties to helium-4. It is unstable, and can be induced to self-annihilate on demand, which releases an amount of energy comparable to a proton-antiproton annihilation. Taimat is less expensive to produce than antimatter, and easier to store.

So it's comparable to matter-antimatter continuous pulse propulsion, then? Cool.

IIUC, acceleration is hard limited by what the inertial dampening system can do to protect the squishy crew members, yes? So the main advantage would be fuel efficiency and range, I suppose?

[Bamax]

Hahaha!

Human ingenuity strikes again! And this has a reference:



ESA (European Space Agency) have been studying this.

The article is so short, I'm going to copy it here. Link to source at the bottom

TLDR: 24G with air breathing, but suspended in liquid. 100+G with liquid breathing as well.

Is there an example design in nature for the perfect acceleration shield? In effect, there is, and it is the egg. We studied the coupling of water immersion with liquid breathing as a possible approach for the “perfect G suit”.

By completely immerging a man in a physiological water solution within a non expandable, rigid container, the increased fluid pressure developed within the cardiovascular system during acceleration is approximately balanced or even cancelled out by the gradient of pressure developed in the liquid tank outside the body. At the same time, water immersion increases tolerance to acceleration as the acceleration forces are equally distributed over the surface of the submerged body. This abruptly reduces the magnitude of localised forces and a homogenous hydrostatic response of the whole body is induced, with evident benefits for blood and lymphatic circulation. The limiting factor is the presence of air in the lungs. Once under acceleration, the immersed subject experiences an augment on external pressure, which will casue squeezing effects on his chest, until all the air present in his lungs is removed. This fact limits the applicability of the technique to a sustainable acceleration of 24 G.

In order to overcome the limit and reach the real potentials hided in water immersion, it is possible to fill the user’s lungs with a fluid. In this way there won’t be squeezing effects. The problem, then, is: how is it possible to breath with liquid filled lungs? The answer came from the field of clinical lung therapy. Here, the use of perfluorocarbon for liquid ventilation was longer studied, demonstrating the feasability and safeness of the concept.

It is hard estimating an ultimate acceleration limit possible with this set-up, but it presumably can be higher than hundreds of G. The ACT is working to assess the application of liquid ventilation for water immersed astronauts, in order to identify the space requirements and to address future studies, designed to overcome current limits of the technique.

(emphasis mine)

https://www.esa.int/gsp/ACT/projects/li ... ation.html

[The article cites some more detailed papers]

From: https://physics.stackexchange.com/quest ... t-g-forces


Conclusion: Humans ask the Loroi why their ships are so slow. When Loroi mentions the 30g max inertial dampener limit, the humans show them the above article and tell them to implement it.


With just water submersion a Loroi designed to exploit faster accelerations could top out at 54g!

With both water and liquid breathing they could top out at about 130g!


The Umiak's jaw would drop watching that... if they had one.

Fast strike force indeed!

[Cthulhu]

I think that the limit is not only the dampening, but the energy usage necessary for the acceleration. There should be a good reason why it's capped at around 30-36g, maybe it's the upper limit where the floater drives are still economically viable? A reactionless drive may go beyond that, but we haven't seen any Historian ships yet.

Ah, yes, the Fuel and Support section of the Insider database provides a good explanation:

FuelShow

Fuel is going to be your critical resource that determines endurance, and it's highly variable... if fuel is carefully conserved, a ship could travel dozens of systems (though not very fast) and stay out for six months or more; but under heavy acceleration and combat conditions, it could expend the same amount of fuel in just a few days. Loroi and Umiak ships would use types of matter-to-energy conversion reactors for power, so fuel in our case is an exotic, volatile material (like antimatter) that requires sophisticated containment (so that your ship doesn't blow itself to bits when you take engine damage or lose power). Ratio of actual fuel mass to containment apparatus mass is likely to be about 1:10. In WWII, large naval warships typically devoted about 15% of the ship's mass to fuel and stores; applying this figure to a 350,000 ton Loroi cruiser, we get a fuel/storage mass of 52 kilotons, or an actual fuel mass of 5.2 kt. Using a reasonable fudge factor for inefficiency in matter-to-energy conversion, this is enough fuel to run the engines at full thrust (30G) for roughly 100 hours. This can be enough fuel for a strike mission lasting about a month, assuming that the ship travels at an aggressive but reasonable pace to the target, makes several hyperspace jumps (both there and on the return voyage), and spends no more than about two continuous days of intensive combat operations. An Umiak warship of similar size would have a lower maximum thrust, more efficient engines and a higher fuel mass percentage, giving it a full thrust endurance perhaps as high as 200 hours.

If we were to increase trust, especially if this exceeds what's a reasonable efficiency margin for the engines, then the ship's fuel tanks would not even last a day. Entire fleets of tankers, on the other hand, would be a prime target for the enemy forces and therefore, a huge liability.

[Bamax]

This would be select forces, not the average Loroi ship.

This is the kind of ship you send in to bombard planets.

It's so fast it can likely get away AND hit the planet


Or station, since if I recall correctly the umiak spacestations the Loroi were unable to take, and the Semoset campaign fell apart from there.

Have trouble flying under high g? No problem get an all Teidar crew! Telekinesis for the win.

And use massive cover fire to screen it's approach... we would not want a bunch of powerful dead for nothing.

[Tamri]

I agree with Cthulhu. The acceleration of the main combatants is not limited by the capabilities of their compensators, but by the power of the engines and the gradient of energy consumption by these engines. Jim wrote somewhere that 90 percent of the ship's energy consumption goes to the engines.

Besides, the creation of a liquid compensation environment will seriously complicate the LSS and reduce the reliability in general, as well as the resistance to combat damage - firstly, the liquid is incompressible, which means that it will have to be stored somewhere, in addition, it has a mass, and if the volume on board the spacecraft, in principle, the value is variable (controversial for military ships), then the mass is not. And secondly, it is difficult to quickly pump out the liquid medium from non-critical compartments in the event of combat situations, as well as to quickly return it back, it will complicate the airlock system, and there are a whole bunch of reasons why, in general, the liquid environment on a spacecraft is a pain.

For all.

[Cthulhu]

Well, let's construct such a ship in our imagination. For that, we'd need a couple of assumptions:

1. Inertia dampeners are not strong enough for those speeds. (Although, since they must absorb the hyperspace jump forces that would otherwise destroy the ship, they just might.)
2. The ship drives can propel it at the desired speeds (That's still twice as fast as the torpedoes, whether it is actually possible is unknown, but highly unlikely.)

The resulting vessel would be little more than a huge, manned torpedo. Perhaps even multistaged, since it would need to decelerate before a jump, and then accelerate again, multiple times. There should be no room left for a payload, instead it can act as a torpedo and simply ram into the target planet with all of its remaining fuel.

However, this gigantic "wunderwaffe" should be just as effective as the historic ones were. That is, a huge waste of resources. It would need an absurd amount of fuel to do some damage to a single border planet? With utterly questionable chances of success? You'd be better off investing in conventional fleet assets.

A true super-weapon would be a FTL cannon, or a hyperspace drive that could reliably perform long jumps over several systems. That's impossible at those tech levels shown in the comic, even for the Historians.

[Keklas Rekobah]

↑ It must be pointed out that inertial dampers are not required to be active while maintaining a constant velocity (e.g., velocity = speed + direction), but only when the ship's vector undergoes change (i.e., in speed or direction).

The inertial dampers of a ship travelling at a constant velocity of 0.998c would not have anything to dampen because, to the ship and its contents, the net acceleration would be zero.

[Demarquis]

Yeah, I think he meant "acceleration", not speed.

By the way, I forget, can someone remind me if ships in this setting use the propellant as fuel, or are they separate?

[Cthulhu]

Yes, I meant acceleration, since high speeds are rather uncommon in Outsiderverse. The transit between systems is instant and the systems themselves are not big enough to warrant (or even allow) speeds above 5%, perhaps 10% lightspeed. After all, the ship would need to decelerate for an outbound jump.

Yeah, I think he meant "acceleration", not speed.

By the way, I forget, can someone remind me if ships in this setting use the propellant as fuel, or are they separate?

It's not fully fleshed out, but here you are:

Quick question Arioch, what sort of propellant does the Loroi use? From the looks of it in your comic, it looks like your average hydrogen propellant at immense thermal energies. If I somehow missed the answer, I must apologize for it.

I'm not certain, but I think it might make sense if it's supercooled hydrogen and/or helium, which could help keep the taimat stable as well as be used as extra reaction mass.

[Demarquis]

That's interesting, in light of the decision by Arioch that fuel only consists of 15% of the total mass of the ship. That was crazy (I didn't see any way to allow the accelerations that were specified), but if propellant is counted separately, that makes more sense.

[Arioch]

The Floater drive uses the effect of the inertial dampers in reverse, to increase the effective inertia of the propellant. So the propellant mass requirement is very small, essentially just the leftover particles from the decay of the taimat (which probably can't be 100% efficient), and the supercooled helium (or whatever) they're using to keep the taimat stable.

Maximum acceleration of ships is entirely limited by the power of the engines and the structural strength of the hull. Inertial damping fields do not have a practical limit (at least within the acceleration envelope of a starship). This would need to be the case, since the gravitational disturbance created by the jump field presumably creates tidal forces far greater than any ship acceleration could produce.

[Bamax]

The Floater drive uses the effect of the inertial dampers in reverse, to increase the effective inertia of the propellant. So the propellant mass requirement is very small, essentially just the leftover particles from the decay of the taimat (which probably can't be 100% efficient), and the supercooled helium (or whatever) they're using to keep the taimat stable.

Maximum acceleration of ships is entirely limited by the power of the engines and the structural strength of the hull. Inertial damping fields do not have a practical limit (at least within the acceleration envelope of a starship). This would need to be the case, since the gravitational disturbance created by the jump field presumably creates tidal forces far greater than any ship acceleration could produce.

Huh? I think what you are saying in scientific terms is the floater drives artificially increase the inertial mass of the propellant as it is flying through and out the exhaust ports?

Basically turning low mass stuff into the equivalent of dense lead shot out at relativistic speeds. Do not get behind an exhaust port... you will get nuke blasted!

It's a nice cheaty scifi drive, since you are tricking the universe to 'think' a 'low mass ball' has as much thrust as high mass one.

I like it. Give us humans one and let us stick it on our weaksauce ion drives. Would probably make our standard ion drives get 1g or greater constant acceleration.

You just inadvertantly solved the weird glowy light drives of star trek. They must all use weak ion drives souped up to go faster with inertial exhaust inertial mass multipliers.

I know they never say that... but it could work actually as as an explanation






Because if you increased the inertial mass of the propellant while it was STILL sitting in the tank then you would make your ships virtually impossible to move or. change course... unless an opposing force was stronger.


Like the force of crashing into a moon, or doing something utterly insane.

Like coasting 50 kilometers per second and launching a harpoon line onto an asteroid moving a relative 2 kilometers to your vessel as you zoom by.

Result? Either your harpoon line tears while your ship tears past, or it holds and you tug the asteroid some, but you also slow down more since now you are tugging a whole asteroid of inertial mass.

[Cthulhu]

Huh? I think what you are saying in scientific terms is the floater drives artificially increase the inertial mass of the propellant as it is flying through and out the exhaust ports?

Basically turning low mass stuff into the equivalent of dense lead shot out at relativistic speeds. Do not get behind an exhaust port... you will get nuke blasted!

It's a nice cheaty scifi drive, since you are tricking the universe to 'think' a 'low mass ball' has as much thrust as high mass one.

I like it. Give us humans one and let us stick it on our weaksauce ion drives. Would probably make our standard ion drives get 1g or greater constant acceleration.

The floater drive is a system that sits in-between the "boring" real-world propulsion as it is described in the Tsiolkovsky equation by cheating with the variables and the true sci-fi reactionless drive. It allows for a more efficient drive system by shifting the ratio of energy/mass propulsion more towards an energy-based one. Otherwise, the ships would need absurd amounts of propellant. The Historian reactionless drives are presumably purely energy-based, while our current chemical rockets are mostly mass-based.

[Bamax]

Since I am a compulsive worldbuilder, I recently made an anti-inertia field drive.... but this was a whole week before today.


It requires rocket engines (of any kind, even modern will do) to kickstart it.

Once the rocket engines light off to the desired acceleration you engage the anti-inertia field drive and then cut off your rocket engines. Once engines go idle you will be pleasantly surprised to still feel the 3 gees of acceleration still going strong... all because of the anti-inertia field enveloping the ship.

How fast you go depends on your rocket engine, but at least the rate of acceleration is constant, while the vector is linear. Meaning you will keep 'falling' in the same direction.


To cut the acceleration you turn off the field, and then to turn it on you light off your main engines again.


Vessels that use anti-inertia drives I imagine would use high thrust pulse rockets. Since they need thrust but only for a short time before the AI (Anti-Inertia) drive takes over to 'copy'what the rocket did at a constant rate.

[Demarquis]

Ok, but what is the energy source for all this again? I realize that this is sci-fi, and I am not really criticizing the canon, but scientifically if the amount of energy you use to dampen the inertia is less than the energy you gain by shooting the propellant out the nozzle... well, that's something.

It's a perpetual motion machine, for one.

[Cthulhu]

Ok, but what is the energy source for all this again?

Taimat, which is some sort of exotic matter that allows for a matter-to-energy conversion reaction without the hassle of antimatter.

I realize that this is sci-fi, and I am not really criticizing the canon, but scientifically if the amount of energy you use to dampen the inertia is less than the energy you gain by shooting the propellant out the nozzle... well, that's something.

It's a perpetual motion machine, for one.

The floater drive cheats with the aforementioned Tsiolkovsky equation by using energy to effectively increase the inertia of the exhaust and therefore "fake" the presence of more exhaust mass. Basically, it trades energy for propellant mass, since it's easier to generate more energy, than to carry more propellant.

[Bamax]

Ok, but what is the energy source for all this again?

Taimat, which is some sort of exotic matter that allows for a matter-to-energy conversion reaction without the hassle of antimatter.

I realize that this is sci-fi, and I am not really criticizing the canon, but scientifically if the amount of energy you use to dampen the inertia is less than the energy you gain by shooting the propellant out the nozzle... well, that's something.

It's a perpetual motion machine, for one.

The floater drive cheats with the aforementioned Tsiolkovsky equation by using energy to effectively increase the inertia of the exhaust and therefore "fake" the presence of more exhaust mass. Basically, it trades energy for propellant mass, since it's easier to generate more energy, than to carry more propellant.

In my head it makes the exhaust much more dense.

My guess is taimat can be be induced to multiply in it's plasma state.... much as a human cell divides. Just to an extreme degree in the case of floater drives. Which would certainly explain the brilliant Loroi plumes... as well as their beam weapons working so well in space.


Either that or the drive just gives the exhaust imaginary or psuedo-mass.

But I honestly prefer it to be actual mass that came from seemingly nowhere, when it's source is the taimat.

Einstein implied energy can be converted into mass, and I reckon that is part of the 'magic' that makes floater drives work.

It is doing all of this simultaneously. If I am right, taimat may be like an exotic form of mass that can not only be converted into energy, but can be converted BACK into mass and reproduce rapidly as well... but only in the plasma state.


If I am right, there would also be a way for Loroi to engineer miniature stars. Using taimat plasma and whatever they use for gravity control.


Cool eh?

I am just glad Arioch never went overboard with technobabble like Star Trek.

A plasma multiplying inertial mass is one thing for exhaust.

But using Star Trek replicators to make a copy of anything you want is kind of plot breaking to me.

[Cthulhu]

Unfortunately, the Loroi (or any other empires) are not yet at the technological stage where they can transform energy into matter, or even replicate it like in Star Trek. The floater drive system does not produce more matter in any way, it simply acts upon the exhaust to achieve more trust with the same amount of propellant.
Just as you said, matter creation is just way too much of a universal plot device that can plug even the laziest plot holes.

[Demarquis]

And yet, if you wanted to be objectively realistic about it, that must be what they are doing (I have no idea what "imaginary mass" could even be). Perhaps they can covert energy into very basic sub-atomic particles, but not more structured objects (like an atom). Or perhaps they can only add mass to a currently existing particle, without altering it's structure in any way. That would prevent any replicator shenanigans.

Still plenty of plot-breaking implications. The Loroi would have access to infinite free energy, for example. They should be at the equivalent of Kardashev II by now, at the very least (although perhaps the war is holding them back). The Historians may be keeping certain trade secrets to themselves, as well.

[Bamax]

Imaginary mass is hard to understand, but I gather that... assuming I understood this wiki well enough, if you had it, you could simulate real mass.

https://en.m.wikipedia.org/wiki/Tachyonic_field