AnotherDilbert
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The rules were very strict, aircraft could only be used at all in a single atmosphere type and of course not without atmosphere:
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1G ship on a 10G world....
- Thread starter Murph
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The rules were very strict, aircraft could only be used at all in a single atmosphere type and of course not without atmosphere:
The thrust and local gravity or gravitational constant are independent of each other, both have an effect through the vehicle's mass, which is unknown. Lifting bodies help to a degree, though they also become drag limited. In physics we usually create a freehand diagram, list the formulas, then do the work. Doing it in games is somewhat futile as it frontloads it onto the ref, and it is weird because then people at the table look at you like whatever. In school, when we were all engineers, I had a friend who was an aero, and he did the math, there, called them magic carpets. I mean talking about ten G's is very massive, and would likely crush the vehicle through pressure anyways, beyond cytherean, near jovian, and one starts to get pressure ices from normal gases. Making things too simple for the story, because it is centered on the pc's, where truthfully, none of this is at all possible. Radiation would kill everybody. Ships would collapse under their own weight by the square cube law. Engines would simply melt by the amount of energy they had to use.
Counting G's also becomes troubling with deck plates, then one has stacked ten decks, the top is 10 G's, where the 10 G ship would be attracting debris like an old Dr Who episode; something else has to be going on. Also if gravity control was so perfect, it would likely be weaponized. It was in some games like Starfire.
So, according to your calculations, it would be impossible for birds, insects and bats to fly and we would never have developed aircraft as the first three and most of the last have accelerations below 9.8 m/s^2. But they can and do fly - all that is needed is to be able to get off the ground and maintain lift. To achieve escape velocity when your acceleration is less than planetary gravity you just need to get airborne and keep accelerating whilst climbing. For high-G planets, you'd need to do a lot of loops around the planet until escape velocity is achieved.In the absence of a gravity well ...
I'm not quite sure how to tell you this (so that you'll believe me) so let's make this as obvious as possible.
+
= (wait for it...)
Count them yourself if you don't believe me.
Where I come from ... 10x Down + 1x Up = 9x Down =
You're asserting this:
Where you come from ... 10x Down + 1x Up = 1x Up =
I can't explain it any plainer than this.
Where your statement does apply would be to a straight up lift from ground to orbit.
Indeed. Aside from the space drives violating thermodynamics, you also have the structures defying materials science and the occupants ignoring the limits of biology.
Reality gets in the way of the gaming experience, it does.
But the specific ways in which one goes about setting aside "the rules" of reality to make the imaginary world "fit for purpose" have a big effect on how things work there.
Keep in mind that it's a system to simulate science fiction for game purposes, not one to simulate a future reality.
And some of the SF it was based on, really did not have it's fictional super-tech thought out very well....
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True, and I agree. I have used some of it in my setting too. Strict interpretations would make the Green Blobs scenario in Azhanti High Lightning impossible, or gas giant refueling. Aero, propulsion engineers from Armstrong Hall, sometimes gather at a pub near my house, and we talk,only a few like science fiction because for the most of them the actual reality ruins it, it is simply impossible. My feeling is the RPG's are all essentially space opera because the game is centered on the player characters. I watched an interview with a designer who was constantly mentioning their game as realistic, and I felt like saying "what about radiation?" Or other such things they had ignored for the most part, it is fine though, they should do what they like. I didn't say anything, I usually don't say anything because why ruin it? I'm happy that people do use the games as a vehicle for science learning.
Spinward Flow
SOC-14 5K
WRONG.
Birds, insects and bats fly ... and the Solomani developed aircraft ... in a 1G terrestrial environment.
All require over 1G of lifting force (usually from wings, but can also be from buoyancy for lighter than air craft and for submersibles or from thrust in the case of engines and rockets) to counteract the downward force of gravity in order to go up.
In a 10G terrestrial environment (the context of the OP question), those same animals and aircraft DO NOT FLY.
The context is 10G of surface gravity.
10G of surface gravity.
If you want to move "up" somehow, you need MORE than 10G of lifting force to get airborne.
10G "down" + 10.01G "up" = 0.01G "up" ... so you can get off the ground ... and float upwards.
To go UP ... you need more UP vector than DOWN vector.
Is this REALLY that hard of a concept for people to grasp?
Spinward Flow
SOC-14 5K
So ... let me see if I've got this excuse of a game mechanic right.
10G of surface gravity =
1G of ship maneuver drive =
Switch on the contragrav with the maneuver drive and you get:
+==
So the way "contragrav" works in the context of the question @Murph asked is:
10G surface gravity DOWN + 9.9G contragrav REDUCTION to surface gravity = 0.1G of surface gravity DOWN effect
1G of ship maneuver drive UP + 0.1G of surface gravity DOWN effect = 0.9G of net maneuver drive UP
That is some utterly INSANE technology required there. Condottiere
SOC-14 5K
In theory, game mechanics tends to first minus off local gravity from thrust potential.
You need to be fast enough to get off the ground, the I would suppose, a large enough wing area to get lift to the altitude that manoeuvre drive is sufficient to allow the spacecraft to slip the surly bonds of gravity.
You need to be fast enough to get off the ground, the I would suppose, a large enough wing area to get lift to the altitude that manoeuvre drive is sufficient to allow the spacecraft to slip the surly bonds of gravity.
AnotherDilbert
SOC-14 1K
Yes, that's TNE.So the way "contragrav" works in the context of the question @Murph asked is:
10G surface gravity DOWN + 9.9G contragrav REDUCTION to surface gravity = 0.1G of surface gravity DOWN effect
1G of ship maneuver drive UP + 0.1G of surface gravity DOWN effect = 0.9G of net maneuver drive UP
Grav vehicles basically work like hot air ballons, and spacecraft use the same tech by default...
On the other hand there were no gravitic drives, but only reaction drives (with magically low propellant consumption).
That is version dependent...
As AnotherDilbert said, in TNE (and IIRC also in T4) your reasoning is correct...
In MT (and I guess Striker, so by default CT) it would be wrong, as gravitics are "pushing", not neutralizing gravity. I'm not sure about other versions...
Nonehteless, MT:SOM specifies MDs may be overcharged up to 400% for short periods, allowing ships to take off from planets with more gravity. Add to this lift based thrust (you can expect quite a dense atmosphere ion such a planet) and, while a 1G ship maybe cannot have enough, a 2G ship is likely to be able to take off, if it has airframe configuration...
Of course, as Atpollard points, another matter is if the crew would be able to survive, and this would depend on the Atrificial Grav plates capacity. As they can neutralize the thrust of a 6G ships and keep normal gravity, they must be at least capable to alter gravity by 7G, so allowing to survive at least up to 8G planet. Not so sure about 10G.
Enable sound on the .mp4 for additional fun.
I guess most ships would be able to keep structural integrity at 10G. After all, most of them have submarine capacity up to quite high depth (and armored SDBs are kept on the sea bottom hidden for long times)...
And the effect would not be that of an impact, but a gradual increase (as going depth into sea).
As said before, though, the effect on internal nviron (and so to people and objects there) would depend on the capacity of the Artificial Grav Plates of the ship.
What is the diameter of a 10G world? With this you can see if it's possible for a 1G ship to land on/lift off of that 10G planet using the Travel Formulas.
From the Traveller Wiki:
I mention this as a 1G ship can lift off of size 9 & A worlds (at least in T20, and it takes a long time to get to 100 diameters) and with a good enough Pilot skill might be able to skim GG's for unrefined fuel.
Another thing, is that 1G ship in the OP built to withstand/survive the 10G environment? If not, it's ability to 1G off of that planet doesn't matter. And can that 1G ship even lift off a 10G world in the rules you are using?
I've come to the conclusion that the Science, Physics, and Natural Laws of the Traveller Universe are slightly different from our own Universe in some ways and similar in others. Sure, I need the things I know of 'My Universe' to understand 'The Traveller Universe', but I don't need things to be exact, as Traveller is a 'Sci-Fi' setting. As long as it works internally in Traveller, I'm ok with it. And yes, I've read the Threads & Posts that discuss the 'Internally Broken Things' in Traveller.
The bottom line is that for the Citizens of the Imperium, we go from those who are happy with Traveller as is and those who want a more realistic Sci-Fi feel, and everything in between.
From the Traveller Wiki:
Travel Formulae[edit]
Travelling in Charted Space: The travel formulae and diagram used by the Imperial Navy and Scout Service show a typical interplanetary journey, and equations which can determine the time required (if distance and acceleration are known), acceleration required (if distance and time are known), and distance traveled (if time and acceleration are known]. All of the formulae use the MKS (meters, kilograms, seconds) unit system, and assume that the ship is undertaking a journey from rest, that it accelerates continuously to the midpoint of the trip, and then decelerates to rest again. [4]
I mention this as a 1G ship can lift off of size 9 & A worlds (at least in T20, and it takes a long time to get to 100 diameters) and with a good enough Pilot skill might be able to skim GG's for unrefined fuel.
Another thing, is that 1G ship in the OP built to withstand/survive the 10G environment? If not, it's ability to 1G off of that planet doesn't matter. And can that 1G ship even lift off a 10G world in the rules you are using?
I've come to the conclusion that the Science, Physics, and Natural Laws of the Traveller Universe are slightly different from our own Universe in some ways and similar in others. Sure, I need the things I know of 'My Universe' to understand 'The Traveller Universe', but I don't need things to be exact, as Traveller is a 'Sci-Fi' setting. As long as it works internally in Traveller, I'm ok with it. And yes, I've read the Threads & Posts that discuss the 'Internally Broken Things' in Traveller.
The bottom line is that for the Citizens of the Imperium, we go from those who are happy with Traveller as is and those who want a more realistic Sci-Fi feel, and everything in between.
What's the escape velocity of a 10G world?
An airframe designed for a 1G world is quite different from one for a 10G world. How big would the wings need to be for a 747 on a 10G world compared to what we have now?
If a vehicle can get in the air, and climb to higher altitudes, and just burn, baby, burn and increase velocity to meet escape velocity, they may be able to get out of the well. The detail is whether the speed they need to go is possible on their ship.
If we're using a thrust model, then a "1G" ship is actually a ship that has a thruster that can push the mass of the ship 10m/s^2. However as that ship accelerates, it starts running into drag problems, and the becomes the question of what's the actual top speed of such a ship in atmosphere, particularly dense atmosphere, and can they actually achieve escape velocity without just having to go "straight up".
Kakistocrat
SOC-12
Without knowing either the mass or the mean density of the world, the question is unanswerable.
If the world’s mass is known, then g = GM ⁄ (r ²), where g is the surface gravity, G is the gravitational constant, M is the world’s mass, and r is the world’s radius.
If the world’s mean density is known, then g = (4π ⁄ 3) Gρr, where g, G, and r are as above, and ρ is the world’s mean density.
A 10 G world means g = 98.0665 m ⁄ s². The gravitational constant G = 6.67430(15)×10⁻¹¹ m³ ⁄ (s² kg). Fill in your choice of M kg (world mass) or ρ kg ⁄ m³ (world mean density), solve for the radius r, and the diameter will be 2r.
Baroun Tardis
SOC-12
T5 supports this. Ships, by default, have "lifters" that cancel their weight
IMTU that’s how MDrive is able to do reaction drive with ridiculously small waste heat ejecta, the ship mass is in grams.
Yes, but what we forget is the handwavium that is Contra Grav, in that it creates a field in which gravity is whatever you set it to at the current moment, so on a 10 G world, you do not have 10 g's inside of your ship, everything is 1G, not 10G, so the drive is only pushing against something at 1G weight and mass. Once Contra-grav comes in things like escape velocity, and mass ratios go out the window. Regrettably I do not have the math to prove it.
That is kind of the thing, you should save your time and devote it to something else. When I was younger I and others we did the math, for this jumps etc.. So I feel sort of compelled to say something, then again I don't want to ruin it. Therein lies the rub ...
Condottiere
SOC-14 5K
If that were true, I'd extend it to include the hull, and go visit the Titanic.
Or more pragmatically, it becomes a forcefield to protect against incoming munitions.
Or more pragmatically, it becomes a forcefield to protect against incoming munitions.
AnotherDilbert
SOC-14 1K
Contra-grav does not affect the mass of the ship or the thrust required to achieve a specified acceleration, as per TNE FF&S, T4 FF&S, or T5 (Lifters).
They just cancel out most of the gravitational acceleration, somehow.
They just cancel out most of the gravitational acceleration, somehow.
